phase one p25 with nikon d3x

Discussion in 'Medium Format' started by andoni_mesa_bravo, Sep 4, 2011.

  1. Hi all i am new in forum :)
    I have a nikon d3x and i am about purchasing a phase one p25 v mount back with 2200 exposures for 3000 euros.
    my question is that if it is and stupid thing as i have the nikon d3x with about the same amount of PX.
    I like the medium format field and DOF over the 35mm and i have the hasselblad 503 cw already.
    Sorry about my english and thanks for you time
     
  2. If you prefer working with the Hasselblad, and you can afford it, it's not a stupid thing at all. Quite sure the Phase One back will have different qualities from the Nikon; the amount of pixels is only part of the story.
     
  3. thanks for the response:)
    I m not very clear about the image quality diferences on thoose two systems.
    Some people says that the pixels on MF are diferent than thoose on 35mm.
    I shoot fashion and the way i work i dont need speed...so i need opinions :)
     
  4. Generally the larger the sensor the greater the image quality. That would be a full frame sensor. I do not think you are going to suffer image quality loss.
    The only other consideration would be your glass. Since you already have the camera, I will only assume you have a decent selection of lenses.
    It should be quite a step up.
     
  5. So... do you think that it would be a nice thing to have the nikon d3x and phase one p25 together?
    my hasselblad 503 cw has the carl zeiss planar 80 2.8 CF .
    Im getting crazy...y dont now what to do...
     
  6. A digital back is an excellent way to continue to use a V system that you already own in the digital era. It is especially appropriate if you shoot fashion or products. Not all pixels are equal. Although the D3x is an outstanding camera, medium format digital is different and in many ways better for controlled photography.
    The P25 will have significantly more resolution than the Nikon, for two reasons. The D3x has an anti-aliasing filter, whereas the P25 does not. Secondly, larger pixels mean the lens doesn't have to work as hard to resolve an image*. The net effect is a 50% improvement in resolution compared to the same number of pixels in the smaller camera. Larger pixels are also quieter than those in the D3x, and the dynamic range is 16 bits/channel vs. 14 bits/channel for the Nikon. Both factors contribute to a smoother appearance and more open shadows.
    One image that sold me on MF digital was that of a motorcycle - black and chrome. The texture of black leather is reproduced very well, along with the bright contrast of the metal. In other subjects, including portraits, MF renders gradients and textures much better than small format, whether film or digital. I don't have the original, but I couldn't resist taking a similar shot on the street.
    * Net resolution is a product of the resolution of each component making the image. If the "errors" in edge contrast were gaussian (a good approximation), the net error is the root sum of squares. In short, if the absolute resolution of Hasselblad and Nikon lenses were about 200 lp/mm (also a good approximation), pixels of the P25 would yield about 40% better resolution.
    Aliasing can be a problem with MF digital, due to the lack of a filter. Repetetive patterns, like bricks or fabric near the edge of resolution show Moire patterns, which can be very hard to remove in post.
    00ZHb6-395483584.jpg
     
  7. You only have one Hasselblad lens. The D3X is a much easier system to use. The "look" of the Hasselblad and P25 may be different but I doubt significantly better. Sharpness of images will not be significantly better. Don't forget that the P25 is a "crop" sensor. It is approximately 36mm x 48mm and not 56mm x 56mm that your 503 with 120 film used to be. This is the part I am concerned about. The sensor is twice the size of the D3X sensor and has less pixels with only 22 MP. It seems to me that you can make same size prints at the same print resolution and get very similar results from both systems.
    Your 80/2.8 with the P25 will give a similar view to a 105mm lens.
    Depending on what Nikon lenses you have I might recommend putting the money into Nikon lenses instead.
     
  8. Edward, my one concern in your post is regarding resolution of medium format lenses compared to 35mm lenses. I don't have all the lpm facts in front of me, but it has always been a known fact that the best 35mm lenses outresolve the best medium format lenses by a significant margin. In the days of film the single biggest advantage MF had was far less magnification of the negative/transparency to achieve the same size print from 35mm film. Since the grain of a 35mm film was the same as the grain of it's 120 format film counterpart, the medium format lens did not have to resolve as well as the 35mm lens to still achieve far superior results.
    In this scenario, with different sensors, the D3X it is like using a fine grain Kodachrome 25 film, and the P25 is like using a large grain Ektachrome 100. By the time you enlarge them to the same size print they will be similar.
    With respect to your motorcycle anecdote, what was the medium format sensor and what DSLR were you able to directly compare it to.
     
  9. maybe i should wait another eternity and buy a p45+ or p40 + ....but the p25 back has a very good price with just 2500 exposures...(3000euros)...i would not want to loose the chance .
    Another thing i like about the p25 is thas the sensor measures 36x49 and for example the p40+ measures 33x44 with i realy do not understand why they call 33x44 MEDIUM FORMAT.it is not even double of a 35mm camera and has the same micron size as my nikon d3x.
    The price of a p40+ is about 16000euros just the back :-0 and the p45+ is about 22000 euros :-0000(
     
  10. There are so few of these around on the used market I have no idea if that is a good price or not. If you know that it is a good price, and you can afford it, then you could purchase it, test/use it, and if you are not happy with it, then resell it for close to what you bought it for. Directly comparing it to your D3X is the only way to truly find out. Anyone who has taken the time, and money, to make this direct comparison is not likely on this site.
    I absolutely concur, to me it will not be medium format until there are at least 56mm x 56mm sensors that can use medium format lenses the way they were meant to be used.
     
  11. what do you think about 33x44mm size sensor? I d like to now why new MF sensor are smaller like p40+, p30+, h4d31 ,h4d40... It is better to have a smaller sensor? i thougt it was better to have a bigger sensor size
     
  12. I like the medium format field and DOF over the 35mm​
    You mean you like deeper DOF, and don't care about the 35mm system's ability to achieve much shallower DOF than a P25 back on a V system Blad? Because the oft-repeated statement that MF has shallower DOF than 35mm is just an urban myth.
    Here's a little bit more mythology (or halucination).
    The D3x has an anti-aliasing filter, whereas the P25 does not. Secondly, larger pixels mean the lens doesn't have to work as hard to resolve an image*. The net effect is a 50% improvement in resolution compared to the same number of pixels in the smaller camera.​
    Of course, there is nothing in optical physics or image processing to support that.
    Larger pixels are also quieter than those in the D3x, and the dynamic range is 16 bits/channel vs. 14 bits/channel for the Nikon. Both factors contribute to a smoother appearance and more open shadows.​
    No. Larger pixels with the same technology are superior to smaller ones. The sensors in current MF backs are so far behind the level of technology in a D3X sensor that if you actually measure the dynamic range instead of quoting urban myths, chicken entrail readings, or hallucinations, you will find that the D3X has the quieter pixels, smoother appearance, and more open shadows. And a 16 bit converter on a sensor noisy enough to mask the last 4 bits with noise is not a tactical advantage of any type.
     
  13. Medium format sensor development has the same problems that DSLR sensor development had. Nikon has crop sensor and full frame sensor camera bodies. It took Nikon several years longer than Canon to develop a full frame sensor.
    I don't follow medium format like I used to but I see since the spring that Phase One has had a pretty much full frame 645 camera with an almost 41mm x 54mm sensor available in 60 MP and 80 MP formats, so hopefully things are improving. Except I for one will never be able to afford one of these even used in the next 15 years!
    I'll have to see what I can do with a stitched Canon 17 TS-E image at 36mm x 48mm on a full frame Canon body.
     
  14. the P-25 is a great back for a lot of things, Someone mentioned the lack of anti aliasing filter, which is one reason for it's sharper images, but the P-25 is particularly prone to the moire problem mentioned before. I used to use one on a 503cw and you would not see it at all on some shoots especially product. But I had some lifestyle or portrait shoots where the moire on fabric was very difficult to deal with. sometimes in almost every shot with certain knit or denim materials. Despite the recommended fixes, very difficult and time consuming to fix. It caused me to upgrade to the p-45 as the higher resolution almost eliminates the problem. If you are shooting a lot of people or fabrics it might not be the best choice.
     
  15. for me the easiest thing to do will be to buy a iq180 MF system but unfortunatly it is a matter of money. That is why i am asking about the p25 back.
    I like the perpective you get with it and change the camera wile working.
     
  16. ok David papas that was a great response for me ,very helpfull, as i would not like to deal with thoose kind of things after spending money so i think i will wait for anotheR oportunty to upgrade to MF.
    Thanks so much :)
     
  17. I have a CFV-16 and a Nikon D3 and D2x. If you crop the square CFV-16 to a 2:3 aspect ratio, you are left with about 13 MP, compared to 12 MP in the Nikons. Consequently, the comparison is fairly straight forward on a pixel/pixel basis. I have a number of images in my Photo.net portfolio which compare resolution and dynamic range between the CFV and various Nikon sensors, MF and 35mm film.
    Larger pixels offer greater resolution than the same number of pixels in a smaller dimension, given comparable performance of the lens. In a CFV-16, there are approximately 109 pixels/mm, which is the smallest detail you can resolve with this sensor. Assuming the lens has a resolution of 200 lp/mm, the image is further degraded by this limitation. An estimate of the net effect is the root-sum-square of the components.
    (1/net)^2 = (1/109)^2 + (1/200)^2
    net = 96 pixels/mm, or 3551 pixels/image width (37 mm)
    The same computation for a D2x gives a value of 3191 pixels/image width.
    You can't make a blanket statement that 35mm lenses are better than MF lenses. It is fair to say that 35mm lenses would have to be much better than medium format lenses to achieve the same performance. That is not to say that they are, in fact, uniformly better. Hasselblad lenses are all very good. Some 35mm lenses are very good, some are not, including some Nikon lenses. Having examined thousands of film images from both cameras, I'd say they're about the same in practice. What they are in the lab is not of immediate concern - I don't take pictures of newspapers and air force targets on microfilm.
    Moire is not a problem if you choose or arrange your subject matter carefully. Fabric, in loose folds, is sufficiently random that Moire does not occur. If you stretch it flat, watch out! Fences, bricks and grain elevators (see my portfolio) can be a challenge. That doesn't happen with the Nikon (q.v., the same grain elevators). The anti-aliasing filter tends to disperse the unsharpened image of edges over 3-4 pixels, whereas the CFV is sharp to the nearest pixel under ideal conditions (good support and good focusing). Most of the resolution advantage is due to this effect.
    Have fun parsing this post, Joseph. You make it so much fun to share my experience. Try adding something this time, not just knocking down.
     
  18. "Because the oft-repeated statement that MF has shallower DOF than 35mm is just an urban myth."

    Apart from DoF itself being an urban myth, is it?
    DoF depends on magnification and f-stop. To create the same compostion on larger formats, magnification has to grow in proportion with the growth of the format. And with it, DoF automatically decreases.
    The only thing that can counteract that is f-stop. So you would be able to open up your 35 mm format lens wider to get the same, shallower, DoF (still given the same composition on both formats.)
    So where's the myth, Joseph?
     
  19. And speaking of myth (urban or otherwise), here's a perfect example:

    "but it has always been a known fact that the best 35mm lenses outresolve the best medium format lenses by a significant margin."

    It's a myth Edward has addressed already, but i think it cannot be stressed enough that this indeed is pure fiction (created mainly by Leitz, as a marketing thing. Repeated - without questioning - ever since).
     
  20. "Because the oft-repeated statement that MF has shallower DOF than 35mm is just an urban myth."
    So where's the myth, Joseph?

    In practice FX excels in shallow DOF because there are many more options for fast lenses in the small formats than medium formats. For example lenses like 24/1.4, 200/2 and so on. I would be happy to see someone demonstrate similar or shallower depth of field (than those lenses give with FX) in any medium format digital system. Of course the angle of view has to be fixed for a valid comparison.
     
  21. Yes, of course the angle of view has to be fixed for comparisons.<br>The larger aperture of the faster 35 mm format lenses (or FX, if you so wish to call them) is balanced by the greater magnification in MF.<br><br>There may be a few exceptions, like an f/1.4 24 mm lens not having a 'DoF matched' MF counterpart. Are there many f/1.4 24 mm lenses? Any?<br>And then, "in practice": how many pictures do you suppose are shot with the lens wide open?<br><br>In short: it's not a myth. It's a general rule. And in practice there may be a few exceptions to the rule, for the lucky few who own superfast 35 mm format lenses.
     
  22. Pnet's own Bob Atkins' website has a reasonably mathematical explanation of DOF, and refers to a more rigorous analysis. In a nutshell, DOF is inversely proportional square root of the image size, given the same distance and field of view and same relative aperture.
    Without the rigor, anyone who has used medium format along with a smaller format in the studio can attest to the relative ease with which you can throw the backdrop out of focus with the larger medium. Considering the high minimum ISO of many small format cameras, you have to fiddle with the lights to use f/4 or wider. Otherwise you faithfully capture every wrinkle and piece of lint on the muslin :)
     
  23. Are there many f/1.4 24 mm lenses? Any?
    And then, "in practice": how many pictures do you suppose are shot with the lens wide open?
    Yes, both Canon and Nikon have 24/1.4's (I have one from Nikon). I shoot it quite frequently wide open. And the picture quality wide open is very good.
    it's not a myth. It's a general rule.
    The OP's 80/2.8 if mounted on a full frame 645 sensor is equivalent to a 51mm lens (typical 50/1.4's are actually a few mm longer). There are autofocus 50/1.4's in the Nikon system. For a half-body portrait subject let's set the focus distance to 2m. For the 80mm lens, on 645, the depth of field calculator gives us 0.15m depth of field at f/2.8. The D3X with a 50mm lens at f/1.4 gives a DOF of 0.13m. The circle of confusion was automatically adjusted by the calculator to 0.03mm and 0.045mm which is approximately correct. Very small difference in DOF but FX wins slightly (and there are faster 50mm lenses in existence if you use manual focus). For other systems than Nikon there are even f/1.0 and f/0.95 available.
    Now, let's look at a 150mm f/4 lens which might be used for a head shot. That would correspond to the angle of view of a 96mm lens on the D3X. I have a 100mm f/2 ZF. MF rig: DOF at f/4 0.06m vs. FX rig DOF at f/2 0.05m. You can argue the difference is negligible here.
    Let's look at wide angle. For a Hasselblad V system there exists a 40mm f/4 lens. That would correspond to 25-26mm lens. I have a 24/1.4 as closest match. DOFs wide open 0.93m (Hasselblad 645) and 0.59m (FX). Clear win for FX.
    Finally, for a longer lens let's look at a 350/5.6 vs. a 200/2 for Nikon. DOF wide open MF 0.0137m vs. FX 0.0108m.
    Anyway, these are with a full frame 645 sensor. For a 36x48mm sensor the lenses available are the same but the DOF will be larger for any given angle of view and aperture than when using a full-frame 645 sensor. For the H system Hasselblad has slightly faster lenses, e.g. 100/2.2. Let's look at that. That's 64mm on FX .. don't have a lens like that but I do have 50/1.4 and 85/1.4. 7.68cm DOF wide open (MF) vs. 4.5cm for FX(85/1.4) and 13.3cm FX(50/1.4). You can argue here that if you want that particular angle of view then you do have shallower depth of field on MF using that full frame 645mm sensor.
    While I may have missed some lenses I think we can conclude that there is no clear-cut advantage to using MF digital to achieve shallow DOF vs. a D3X except in individual special cases. FX can achieve shallow DOF across a greater range of focal lengths though of course you have to pay real money to get it (but nothing like a MF digital camera with a full-frame sensor). Now, in the past it used to be that 35mm lenses were quite crappy wide open but things have come a long way since that time - the latest f/1.4 AF-S Nikkors are excellent and can be safely used wide open. Also, if you get to actually employ the V system lenses on a 6x6 sized sensor then the tide shifts a bit but I am unaware of anyone with that big a general-use (non-scanning) sensor.
     
  24. anyone who has used medium format along with a smaller format in the studio can attest to the relative ease with which you can throw the backdrop out of focus with the larger medium. Considering the high minimum ISO of many small format cameras, you have to fiddle with the lights to use f/4 or wider.
    Yes, there is a discrepancy with studio flashes made at a time when 8x10 film was normal to use in the studio, and the requirements of modern cameras. I've ran into that myself. Anyway, I calculated that with two Ranger Quadras and big softboxes you can actually shoot at f/1.4 at ISO 100 (which is the base ISO of OP's D3X) at the lowest flash energy setting. It has a greater range of adjustment than typical studio flashes but can take the same modifiers. That's a fairly faint blip and I guess any leak of existing light would create a problem. Alternatively you could use LEDs.
    FX has the nice advantage that you can utilize any light - if it is bright enough that you can see anything at all in it, you can make a photograph using it. Okay, a fashion photographer will need controlled color spectrum of the light source. Let's see ... an iPad ;-)
    http://fstoppers.com/jesse-rosten-uses-ipad-studio-lighting
    (I like LCD monitors to light my office portraits after daylights have dimmed - try doing that with medium format.)
    Anyway, I suspect a more typical situation for a fashion photographer would include enough DOF to show the details of the clothing so this discussion is probably academic. ;-)
     
  25. So there we have it: due to the increased magnification, larger formats have less DoF. You must compensate on smaller formats by using larger apertures if you want the same shallow DoF.<br>No myth in sight anywhere.<br><br>(Not, of course, until we begin to talk about how much DoF there is. ;-) )
     
  26. Apart from DoF itself being an urban myth, is it?
    DoF depends on magnification and f-stop. To create the same compostion on larger formats, magnification has to grow in proportion with the growth of the format. And with it, DoF automatically decreases.​
    To create the same print (remember those) magnification decreases (decrease is the opposite of "grow") for larger formats.
    The larger aperture of the faster 35 mm format lenses (or FX, if you so wish to call them) is balanced by the greater magnification in MF.​
    OK, now you're on to something. (But "FX" is pretty much a Nikon term. Let's stick with the term that millions of photographers use, FF. We'll let "MF" stand as short for "medium format", despite maybe 10 times as many photographers using it as an abbreviation for "manual focus". Sorry, time moves on, language evolves).
    There may be a few exceptions, like an f/1.4 24 mm lens not having a 'DoF matched' MF counterpart. Are there many f/1.4 24 mm lenses? Any?​
    The reality is that in pretty much every focal length bracket, a common FF lens exceeds the shallow DOF abilities of the "DoF Matched Counterpart" or "DMC" (I like your term, I think I'll keep it. Thanks). The "few exceptions" are the MF lenses that are DOF matched to FF counterparts.
    645 has a 70mm diagonal. 35mm has a 43.3mm diagonal. I'm not going to get into which aspect ratio is "better", they're each suited to different styles of photography.
    • Neither system offers a decent "fl = diagonal" or "1x" normal, they both tend to the 1.15x normal. That's 50mm on FF, 80mm on 645. Nikon and Sony have 50mm f1.4 normals. The DMC (thanks again!) for 645 is an 80mm f2.2. The fastest production lenses from Fuji/Hasselblad and P1/Mamiya are 80mm f2.8. Canon offers a 50mm f1.2, the DMC for that is an 80mm f1.9.
    • I spend a lot of time with a 2x portrait tele, an 85mm on FF. Mine is an 85mm f1.4 Nikkor, and there's also a respectable 85mm f1.4 for Sony and an 85mm f1.2 for Canon. The DMC is a 135mm f2.2. It's not rocket science to build, Nikon and Canon build them for FF, but they could be extended to cover MF. But Mamiya and Fuji/Hasselblad don't make them. Blad makes a 150mm f3.2, Mamiya a 150mm f2.8.
    • I also spend a lot of time with a 3x portrait tele, a 135mm f2.0 Nikkor. The DMC is a 218mm f3.2. Blad and Mamiya both make a 210mm f4.
    Oh, and since you made a big deal about the 24mm f1.4...
    • I have the dirt common 24mm f2.8. Tiny little thing, 270g, and you can get one for about $400. The DMC is 39mm f4.5. Blad makes a 35mm f3.5 But that's a $4,000 lens, weighing in at 975g. So, to toss your own question back at you... Are there many f/3.5 35 mm lenses? Any? And then, "in practice": how many pictures do you suppose are shot with the lens wide open?" The "any?" 24mm f1.4 comes in at half the price and 2/3 the weight (just 620g) and still manages to best the snot out of the Blad on DMC.
    I really like the comment
    for the lucky few who own superfast 35 mm format lenses​
    Let's have a look at that "lucky few".
    • 50mm f1.4 - Roland Vink's compilation of Nikon serial numbers says that there's been 825,990 autofocus 50mm f1.4 Nikkors built. Throw in Canon and Sony, and the "lucky few" is about 2 million people. Contrast that to the AF Blad H system or Mamiya 645AF 85mm f2.8.
    • 85mm f1.4 - The "lucky few" for Nikon AF is 103,658.
    • 105mm f2.0 - There's 30,859 AF Nikkors out there. How many 210mm f4 Blad H lenses do you think there are? Who's the "few"?
    • 24mm f1.4 - In just a year since introducing theirs, Nikon sold 8,252 of those. In that same year, the total combined MF body sales for Fuji/Blad and P1/Mamiya was under 6,000 units, so how many 35mm f3.5 lenses do you suppose Blad sold in that time? Again, you're confusing who the "lucky few" are.
    My assessment of MF's DOF advantage over 35mm being an urban myth stands.
     
  27. hi Edward Ingold you are right i m gonna said something to share and have fun :)
    Going back to the real question on this i have to say that i was curios to see what was the opinion about Md and 35mm systems with the same amount of PX.
    I have a very good chance of getting in MF camera for a littel money...but at the end i already have a nikon d3x that works great and if i want to get into MF i want to go into a new tecnology MF with is one of the main features of MF systems.
    The main features of MF systems are at the end , more MP , bigger sensor, high sync speed , and the feeling of having deeper images that is very important to me.
    I not speaking about very tecnical things because for me at the end is more a practique thing.
    For example:The sensors of the cameras are not built for our cameras, they are built for a general porposes and are cuted in diferent sizes ....some pieces goes for mobiles,others bigger piezes for the NASA.....is not a photographer who tells how must be a chip, because if it will be like this the MF chips will be 64x64 , 12micron the size, and that in the real world is very very very espensive.That is why they put a lot of MP together on a chip .
    My nikon d3x has a lot of MP all together on the chip with 5,8 micron size and works great ,like it will a MF system of 37x49 with 50PM because also for my experiance the more MP the more DR and DETAIL.I had the d700 with a big micron size and all thoose things and when i change to the nikon d3x was very a new step on image quality.
    About how the lenses works on 35mm or MF i have to say that both are very good but the way i work , i never go to F1.4 or F2.8. The maximum i open is at F4 so with MF to have the same DOF it will be ok F. 7 and i will win more in IQ.
    MF is an incredible system but just when it makes sense, i mean ,Get MF with all the ultimate tecnology as you will with 35mm.One of the advantages of MF is megapixel count with nice size of micron ( 6 )and sensor size,(and when i say big sensor i mean all the beautyfull things that means.
    I am sure the diferences between a micron size of 9 and 6 no one could tell
     
  28. I use nikon d3x and last month I received my CVF-39MP digital back with 10% redeem from hasselblad, the difference between d3x and the hassey back used on 503CW and the CW winder is another type of experience.
     
  29. totally agree!!!i m sure you are gonna love it :)for a looooooong time
     
  30. Joseph,
    In your calculations/argument, you are missing out on most of the fastest MF lenses.
    - 45/2.8 for Mamiya 645 and Pentax 645
    - 50/2.8 for Rollei 6x6
    - 75/2.8 for Pentax 6x7
    - 80/1.9 for Mamiya 645, 80/2 for Contax 645, 80/2 for Rollei 6x6, 80/2 for Norita 6x6.
    - 110/2 for Hasselblad 6x6 and Rollei 6x6
    - 105/2.4 for Pentax 6x7
    - 165/2.8 for Pentax 6x7,
    - 180/2.8 for Rollei 6x6 and P6/Kiev 6x6
    - 200/2.8 APO for Mamiya 645
    - 300/2.8 APO for Mamiya 645 (and I believe there was also one for Hasselblad 6x6)
    - 400/4 for Pentax 6x7
    - 500/4.5 APO for Mamiya 645
    This is not an exhaustive list; I am picking the ones I can think of from memory. There are also many I've left out (lots of 300/4s etc.), but I'm not including them if there is a much faster one in the same focal length (like the Mamiya 300/2.8).
    The wideangle end is still where MF lacks fast lenses, but I have included a couple of f2.8 lenses above. On a 48x36mm digital back, these would be akin to roughly f2.0 wideangles on FF/35mm.
    The Hasselblad, Pentax and P6/Kiev lenses can all be used on the 645 cameras with an adapter, thus increasing their effective system size of fast lenses. The Mamiya 645 system (which is what I primarily use) comes out on top; its own offerings are generally the fastest in their focal length category, plus it can also take all these adapted lenses.
    Including these overlooked lenses would alter the balance of your conclusions. Maybe you should recalculate and repost the DMC comparisons.
    Also, I know that this thread started with digital backs, but if you also recalculate using the full film frame sizes (645, 6x6 or 6x7, as the case may be), you see how on film at least, it is possible for MF to compete on wafer-thin DOF with 35mm/FF. That Pentax 75/2.8 I listed above may not seem very fast, but remember that on 6x7 film it's the equivalent of a 35/1.4 wideangle on 35mm/FF.
     
  31. Joseph,

    You're absolutely right that DoF depends on the final magnification. That does indeed mean that printing to the same size paper, the balance is redressed.
    It's a conditional thing though (as so many other things): if, for instance, you were to assume that larger formats are used to make larger prints (due to printability limits), the thingy evaporates again.
    But still.

    (By the way: unless you reduce the format, print an image that's smaller than the negative itself, you do not "decrease" magnification. I don't know many people who make post stamp sized images from MF negatives.)

    You claim that the "few exceptions" are the lenses that do have a DMC, mentioning in your example the need for a "39mm f4.5" to match the "dirt common" f/2.8 24 mm lens you have, and go on as if that would be an improbable proposition. There are quite a few, not very exotic, MF lenses that meet that, and are even 1/3 stop faster.

    Then you list a number of superfast 35 mm format lenses, and would have us believe that there are huge numbers of those. Good to know, for instance, that there are no less than 103,658 f/1.4 85 mm lenses.
    But how many f/1.8 85 mm lenses are there? How many "dirt common" f/2.8 24 mm lenses are there against how many f/1.4 24 mm lenses?
    In short: what's the proportion of 35 mm format shooters who own such a superfast lens?

    And still: what's the percentage of images these lucky few shoot using these lenses are shot wide open? Not a lot.

    But be that as it may, it really doesn't matter
    Your assertion that less DoF is a myth hinges on the willingness to believe that there are enough 35 mm lenses that have apertures fast enough to balance the decrease of DoF with increasing format, to make the decrease in DoF with increasing magnification a non-phenomenon.

    Think about that: you need to do something (produce faster lenses, or use lenses at larger f-stops) to balance something that you say is a myth and non-extant.
    Hmm... ;-)

    Now had you built your case on that "same final print size" thingy, it would have made more sense. Not that that would make the decrease in DoF a myth either. But still...
     
  32. Andoni,
    As we swung way off track, I'd like to get back to your questions:
    maybe i should wait another eternity and buy a p45+ or p40 + ....but the p25 back has a very good price with just 2500 exposures...(3000euros)...i would not want to loose the chance .​
    2500 exposures is like a newborn baby in the digital back world. You really don't need to pay much heed to the shot count on a digital back, because each actuation is purely electronic, and does not involve any moving parts. The shutter count would matter, but the shutter is somewhere else, in the lens or camera body.
    €3000 sounds like a pretty good price. The P25 uses a Kodak 22 MP, 9 micron sensor, which I would prefer any day over backs based on the noisier and less sensitive Dalsa 22 MP, 9 micron sensor.

    Another thing i like about the p25 is thas the sensor measures 36x49 and for example the p40+ measures 33x44 with i realy do not understand why they call 33x44 MEDIUM FORMAT.it is not even double of a 35mm camera and has the same micron size as my nikon d3x.
    The price of a p40+ is about 16000euros just the back :-0 and the p45+ is about 22000 euros :-0000(​
    and
    what do you think about 33x44mm size sensor? I d like to now why new MF sensor are smaller like p40+, p30+, h4d31 ,h4d40... It is better to have a smaller sensor? i thougt it was better to have a bigger sensor size​
    Yes, it is better to have a bigger sensor size, but only if the pixels behave the same. The difference between the 33x44 mm and 36x48 mm families is that the former have microlenses over the pixels, which changes (improves) their behaviour. This gives the 33x44 mm sensors about 1 stop more of true ISO sensitivitity (signal to noise) for the same pixel size. Some people prefer this to the extra sensor area and higher pixel count of the 36x48 mm ones. So the question a digital back shopper has to ask, is "Do I want 1 stop higher ISO, or 25% more pixels and wider angle coverage from my lenses?"
    You mention the P40+, but that is not the right one to compare with the P45+....the P30+ is the smaller microlensed brother of the P45+; both with 6.8 micron pixels. A CCD generation earlier, the P21+ was similarly the smaller microlensed brother of the P25+; both with 9 micron pixels. Phase One have not used the 6 micron Kodak sensors (a terrible mistake on their part, IMHO: the Dalsa 6 micron sensors they chose just cannot do long exposures) but Hasselblad do use them: the H4D-40 is the smaller microlensed brother of the H4D-50; both with 6 micron pixels. See the pattern?
     
  33. Ray
    I like your opinion and i would like to ask you some thing
    When you speak about that the h4d 40 is the little brother of the h4d 50 you mean that the chip of the h4d 40 is the same but kodak have cut the chip smaller?
    for me the specs of the h4d 50 are the right ones for what i do.
    thanks for your response
    i d like to open a new question about what people now about phocus software from hasselblad
    thanks so much everybody. ALL OF YOUR RESPONSES HAVE BEEN VERY HELPFULL FOR ME :)
     
  34. In your calculations/argument, you are missing out on most of the fastest MF lenses.​
    Not really, no. You've listed lenses that aren't made any mode, many of which aren't available in auto focus, and many of which come from companies that are now out of business. Same reason I didn't mention the Canon 50mm f1.0 or similar lenses for FF.
     
  35. Joseph,
    You've listed lenses that aren't made any mode, many of which aren't available in auto focus, and many of which come from companies that are now out of business.​
    You're now throwing in extra qualifiers, which were not present in your original statement:
    Because the oft-repeated statement that MF has shallower DOF than 35mm is just an urban myth.​
    To MF users, such as people on this forum, MF means any MF system or lens you can buy today, new or old, manual focus or auto focus, film or digital.
    Of course, if you shift the goalposts like that, you can win any argument.
    When that statement was most "oft-repeated", these companies were in business, these lenses were being made new, and MF autofocus was still a twinkle in some Japanese designers' eyes; as were 35mm FF digital, Nikon 24/1.4 lenses, and many other fast 35mm lenses on that side of the argument. So was it an urban myth in those days too?
     
  36. I'm not shifting anything, Joseph. It's just not a myth.<br><br>It's not that regardless of whether MF cameras and lenses are still made or not.<br><br>It also has nothing to do with autofocus.<br><br>It's the simple thingy about DoF depending on magnification and f-stop, such that when magnification goes up, DoF gets less, and you have to open up the lens to keep DoF the same.<br>To make your statement work, you would have to show that the smaller formats lenses are both significantly faster than their larger format counterparts, and that smaller format users typically do not stop down, favour changing shutterspeed instead to arrive at the setting needed to expose their films properly. I wish you good luck trying! ;-)<br><br>If there is a myth (apart from the thing about DoF as an quantifiable entity), it's your statement that it's an Urban Myth.
     
  37. The depth of field is inversely proportional to the size of the format (not the 1/square root of the size as I stated previously), given the same distance, field of view (i.e., focal length), relative aperture (f/stop) and viewed print size. Among the assumptions is that the DOF is defined by a 250 micron circle of confusion (4 lp/mm) in a print viewed from a distance of 10 inches. In other words an APS-C sensor, with a cropping factor of 1.6, has 1.6x the DOF of a 35mm (24x36mm) image. A 6x7 image has 0.4x the DOF of a 24x36mm image. The additional magnification required of a smaller image is taken into account.
    The math for this conclusion is found in the cited reference, together with the simplifying assumptions.
    http://www.bobatkins.com/photography/technical/digitaldof.html
     
  38. To the OP ... if you can afford it, get the P25 for your Hasselblad. It'll open up a new world for you that is quite different than working with a 35mm DSLR. If you can afford it, also keep the 35mm DSLR because it is a different way of working that provides AF speed and versatility for certain subject matter. It is a win-win proposition. Zeiss lenses for the V cameras are quite distinct in their character, and this remains true for digital capture. In fact, my preference for the V lenses is the use of the "Fat Pixel" backs, and had someone made a 56 X 56 sensor with 9 micron pixels I'd probably still be using a V system.
    While it is true that the Phase One P-25 and any other so called 9 micron "Fat Pixel" digital back can produce Moiré patterns in high frequency patterns such a clothing ... it is not all that frequent of an issue, and can be resolved by a few different means. One is to alter the distance to the subject and if that doesn't work, Capture One software used for Phase One backs has an amazing tool to deal with it which has come a long way since the introduction of the P25.
    Personally, I prefer CCD sensor cameras and digital backs without filtration, and the occasional penalty of moiré, over the aggressive AA filter pixel smearing of most CMOS sensor 35mm DSLRs.
    The issue of whether DOF is an Urban Myth is somewhat a moot point. It is what it is. Sure, when comparing a 24/1.4 or 21/1.4 there is no equivalent in MFD that I know of. However, my Hasselblad HC 100/2.2 AF lens on a H4D/40 shot side-by-side with my Leica M9 with a manual focus Leica 75/1.4 are almost impossible to distinguish for one another in terms of DOF and focus fall-off when printed @ 8" X 10" ... The Bokeh may be different due to the characteristics of each lens, but the DOF effect is visually identical.
    When I upgraded from a Hasselblad H4D/40 with a 1/3X crop factor to a larger sensor near 645 sized sensor H4D/60, it was immediately apparent that DOF became more of a consideration at the same distance using the same lens at the same aperture.
    A perfect example of Medium Format DOF and focus fall off can be seen with the new Leica S2 37 meg "tweener" medium format system which has some very fast optics for Medium Format ... all of which are AF. The 120/2.5 Macro has the shallowest, wafer thin DOF of any camera mounted Macro lens I've ever encountered. It has the visual appearance of a Leica Summilux when shot at closest distances wide open. Not many 100/1.4 Macros in 35mm optics that I know of.
     
  39. Correction: H4D/60, it was immediately apparent that DOF became more of a consideration at the same FOV using the same lens at the same aperture.
     
  40. Mark said:
    Personally, I prefer CCD sensor cameras and digital backs without filtration, and the occasional penalty of moiré, over the aggressive AA filter pixel smearing of most CMOS sensor 35mm DSLRs.​
    While I agree with Mark, I have to add: lest anyone get the impression that CMOS implies AA filtration and CCD doesn't, that's not the case. If digital backs were made with CMOS sensors and (more) DSLRs were made with CCDs, you wouldn't notice the difference (well, actually, the digital backs would be greatly improved by CMOS, in terms of readout and dark noise, but that's another issue!). The presence or lack of an AA filter is independent of the sensor technology. CCD-sensored DSLRS like the pre-D3/D300 Nikons have an AA filter; companies will happily remove the AA filter from your CMOS or CCD DSLR for a few hundred bucks; and some CCD digital backs and DSLRs can have an accessory AA filter added (Kodak DCS and Mamiya ZD for example).
     
  41. As I clearly said Ray ... "MOST" CMOS sensored DSLRs."
    Remove the AA filter from a 35mm DSLR and kiss your warranty goodbye. No major maker currently makes a CMOS 35mm DSLR without an AA filter. As high ISO's became the marketer's siren's song, the AA filters have gotten more aggressive.
    Regardless of personal opinions about the use of CMOS verses CCD sensor in a Medium Format Digital back, the fact is that not one maker has produced a CMOS MFD camera kit ... not Hasselblad, not Phase One, not Pentax, not Leaf, not Sinar, not Leica. No one. From 16, 22, 31, 39 40, 50, 60, 80 and 200M/S meg backs ... they all are CCD.
    If CMOS would be the ultimate imaging step up for MFD systems, I'd hazard a guess that one of these players would have done it and trumped all the others in this highly competitive photographic niche.
     
  42. Check out the DOF calculator at:
    http://www.dofmaster.com/dofjs.html
    You’ll see that when photographing a subject at 15 feet for example, with a 50 f1.2 on a 35mm camera, the DOF is 1.94 feet….the same setup on the Contax Zeiss 80 f2 would have a 1.9 feet DOF….or about 1/2” shallower. That is far to tiny to be seen by anyone. With a Mamiya f2.8 80mm lens, the DOF is 2.7 feet.
    This isn’t to say the rendering will be the same, but the idea that MF, especially above f2 is shallower than 35mm, is nothing but a myth.
    Probably the easiest thing to do is to look at the actual DOF offered by two lenses, one MF and one 35mm. Looking at an f1.4 lens for example, one can pick the Zeiss, Nikon or Canon offerings. For MF, say we look at the 80mm f2.8 lens.
    Given a subject distance of 15 feet, both will offer an equivalent FOV….neither will be wider nor more of a telephoto than the other.
    In the case of the 50 f1.4 on a 35mm body, with the subject at 15 feet, everything from 13.9 feet to 16.2 feet will be in focus. Thus the total DOF is 2.3 feet
    With the 80mm f2.8 on the MF body, with the subject at 15 feet, everything from 13.8 feet to 16.5 feet will be in focus. Thus the total DOF is 2.7 feet.
    The problem comes up when people talk about using the 50mm focal length on both. Of course, to obtain the same field of view, one would never do that. If two photographers are photographing a subject, one using the 50 and the other using an 80….both “normal” lenses on 35mm and MF 645 gear respectively, then the photographers would both be at the same camera to subject distance to maintain the same field of view.
    Using a 35mm film body with a normal 50 f1.4 lens, and using a MF645 body with an 80 f2.8…..both taking the exact same picture, in this case, the 35mm film body with exhibit a shallower DOF. In the case I mentioned previously with the 50 f1.2 on the 35mm body, and the Zeiss 80 f2 on the 645 body, the DOF will for all purposes, would be identical.
    I did the ruler test on this about 15 years ago and found that the MF shallower DOF issue is nothing but a myth. The physics backs this up.
    And yes, we are comparing an f2 lens with an f1.2 lens, or f2.8 to f1.4….because we can in this case. If the MF cameras had 80mm f1.4 lenses, then yes, the format sizes would allow the MF to have a far shallower DOF. The problem of course is that the lenses available to 35mm users are far wider than their MF counterparts. As such, 35mm users have the benefit of having an equivalent, or even shallower DOF than the MF users can obain.
     
  43. Apples and oranges, Dave.<br>Dofmaster uses different criteria for acceptable CoC size for different formats. (Part of the Real DoF Myth.)<br>If you really want to compare DoF (and not what people think would be acceptable DoF for different formats), those 1.94 ft using an f/1.2 50 mm lens are matched by 1.27 ft for an f/2 80 mm lens.<br>If you also take the aperture out of the equation (after all, the larger opening is only used to counter the effect of higher magnification) those 1.94 ft are facing 0.75 ft. Less than half.<br>A myth? Apparently (!) not.<br><br>So the bottom line of it still is that you need to have faster lenses (and indeed use them at wider apertures) to counteract the effects of what is said to be only a "myth". Hm... how can that be?<br>And because you have to, it's casually assumed (without blinking an eye) that most 35 mm format lenses are indeed faster and are used at larger openings. A brand new myth in the making.<br><br>Why is it, by the way, that people want the smaller format to have shallow DoF? That, in a world in which people use thingies like "f/22 and be there" as tag-lines?
     
  44. To MF users, such as people on this forum, MF means any MF system or lens you can buy today, new or old, manual focus or auto focus, film or digital.
    Of course, if you shift the goalposts like that, you can win any argument.​
    I didn't "shift" anything. As I pointed out, if you take the long-discontinued MF (that's manual focus, because I speak "English", not "forum") medium format lenses (mostly from camera companies that don't exist any more) and compare them to the long-discontinued MF 35mm full frame lenses, then 35mm FF still wins, or ties. So, the medium format advocates, who describe medium format as having shallower DOF in a definitive, absolute, "this is a characteristic of the format" system are, indeed, repeating mythology. The plain and simple truth is that, any time you compare apples to apples, medium format to full frame, whether it's modern AF lenses from current companies or antiques, there's no clear DOF advantage to medium format. It went from being, at most, at par with FF decades ago, to being about a stop behind today.
    And it gets even worse when the overly aggressive medium format advocates start throwing in words like "much" shallower or "always" has had. You used to get a lot of that from camera salesmen, photography teachers, and yes, people who speak "forum", instead of English.
     
  45. Joseph,

    Why it would be an "advantage" is what puzzles me.

    But as long as you believe there is something called DoF, there is no escaping that with increased magnification, it (DoF) is reduced.
    There is also no denying that to create the same composition, magnification has to increase in step with format size, i.e. that DoF automatically is reduced when you step up to larger formats.
    The only myth here concerning that, is that it would be a myth.

    It has nothing to to with "advocates" etc. Though you apparently see it as a contest, an "A is better than B" thing.
    It's just the way it is: "the plain and simple truth".

    It also has nothing to do with modern lenses v.s old lenses. You can't design a lens to have shallower DoF at the same magnification and f-stop, or more DoF at higher magnification and the same f-stop.

    And it has even less to do with language and the use thereof.
    The refuge of the aggrieved corrected, to start complaining about irrelevant things... ;-)
     
  46. Dofmaster uses different criteria for acceptable CoC size for different formats. (Part of the Real DoF Myth.)​
    And I thought you were beginning to understand. They use different CoC sizes because that's part of all standards for measuring DOF. The CoC for film is calculated from the CoC for the final print.Change the final print size, and you change everything, the DOF criteria, the required sensor (or film resolution), the acceptable diffraction blur.
    Why is it, by the way, that people want the smaller format to have shallow DoF?​
    You're requiring us to accept your premise before we can answer. There's a name for that particular logical fallacy, the loaded question, and the classic example is the question "have you stopped beating your wife". People want pretty much whatever format they're using fulfill their particular vision. Manufacturers with a decent amount of resources respond to the large variety of photographer's visions.
    That, in a world in which people use thingies like "f/22 and be there" as tag-lines?​
    You're doing it again. Google the original "f8 and be there" and you get 124,000 hits. Google your f22 version, and you get 3,280. You actually find more mention of "f16 and be there" (which I tossed in simply as an example of how silly you're being), 3,450 hits. "f4 and be there" gets a whopping 16,600 hits, more than f16, f22, f32, and f64 put together. The actual f-stop in the tag line isn't all that important, it simply means "be ready to shoot". "Be there" is pretty self explanatory.
     
  47. The 120/2.5 Macro has the shallowest, wafer thin DOF of any camera mounted Macro lens I've ever encountered. It has the visual appearance of a Leica Summilux when shot at closest distances wide open. Not many 100/1.4 Macros in 35mm optics that I know of.​
    You don't need an f1.4 (although I have some old f1.4, 1.1, and even 0.7 macro lenses in my collection). Since the S2 has a 55mm diagonal sensor and the FF cameras have 43.3, the ratio of the diagonals is 1.27. So, the equivalent of a 120mm f2.5 lens is a 94mm f2.0. Cosina/Zeiss makes a simply amazing 100mm f2.0, and the bokeh is surprising. Tamron makes a 60mm f2.0 that's a lot of fun. ;)
    Remove the AA filter from a 35mm DSLR and kiss your warranty goodbye.​
    Actually, no. A competent tech can do this without kissing anything (aside from myths and misconceptions) goodbye. It's not a difficult matter for the tech that swapped the AA filter for clear glass to put it back. Nikon's or Canon's techs can't tell that a decent independent technician has been in the camera.
    No major maker currently makes a CMOS 35mm DSLR without an AA filter.​
    This is true. That is because no major maker makes anything without an AA filter. Only the niche and specialty makers make cameras without AA filters. (Personally, I put this down to the high cost of AA filters in niche market quantities and the general inability of most medium format shooters I've seen to work at the apertures that make their 30-60mp resolutions actually worthwhile. But that's a topic for another day).
    As high ISO's became the marketer's siren's song, the AA filters have gotten more aggressive.​
    No, they've actually become less aggressive. I've measured the PSFs.
    Regardless of personal opinions about the use of CMOS verses CCD sensor in a Medium Format Digital back, the fact is that not one maker has produced a CMOS MFD camera kit ... not Hasselblad, not Phase One, not Pentax, not Leaf, not Sinar, not Leica. No one. From 16, 22, 31, 39 40, 50, 60, 80 and 200M/S meg backs ... they all are CCD.​
    Yes, that is indeed a fact.
    If CMOS would be the ultimate imaging step up for MFD systems, I'd hazard a guess that one of these players would have done it and trumped all the others in this highly competitive photographic niche.​
    Then you have hazarded an incorrect guess. More accurately, you have made a logical fallacy. What you have done is observed a real phenomenon and postulated a totally incorrect explanation for it. The harsh reality is that the specialty market (and that even includes Leica's MF (manual focus) 35mm systems, as well as their medium format) is not large enough to gain access to CMOS sensors. Nikon and Canon are "drivers", they each do over $4 billion/year in APS and FF sensor business. Nikon says "jump" and Sony Semiconductors says "how high?" Other billion dollar babies include Sony, Panasonic, and Samsung. P1 (which includes Leaf and Mamiya), Blad, Leica, and Pentax's medium format operation are "passengers". They do about 1/1000 the sensor business of a Nikon or Canon.
    Making a sensor up to about 20x30mm is not hard. That's the largest size for the optical components of a stepper, the machine that exposes integrated circuits. There's dozens of fabs in the world who can shoot sensors that size. It's a huge chip, big enough for the biggest processors, memories, or analog systems.
    To make larger sensors requires a technique for "stitching" chips, to do multiple exposures of 20x30 tiles to make the larger components. The stitching techniques vary, depending on the design of the chip. CCD sensors require very deep implantation or thick epitaxial growth (or both) of strongly doped materials, but not too complex metalization, and it's only single acting, so symmetry is not important. CMOS is entirely different, symmetrical, with complex metalization. Once you manage to get stitching working on a particular line in the fab, that's it, you've only got one line, one technology. Philips (later DALSA) and Kodak only got stitching working on their large cell CCD lines, because that was what their aerospace customers wanted. That's the "driver" in medium format sized sensors. Canon got stitching working on their own CMOS line, Nikon (who doesn't own a fab, but makes the equipment used by many fabs) got CMOS stitching lines up and running at both Sony and Toshiba.
    Medium format almost had CMOS. Kodak, back when they were actually fighting for life, instead of their current business plan of having a profitable death, worked with Fill Factory to get stitching going at Tower and XFab, and failed pretty miserably in both ventures. So, basically, without an amount of funding 10-100x the total worth of the medium format business, there's not going to be any medium format CMOS. There's also a rather scary possibility that Kodak and DALSA may stop giving eyedroppers of aerospace tech to P1 and Blad, or that the aerospace "drivers" may steer the course of sensor development in a direction that makes them less suitable to general photography. Or that aerospace may adopt CMOS. ;)
    In any case, it's not P1's, Blad's, Leica's, or Pentax's decision. Medium format digital, to paraphrase Scarlett, has always relied upon the kindness of strangers.
     
  48. Well, Joseph,

    You probably still think you understand DoF, but you (again) show you do not.
    I know why The Real Dof Myth uses different CoCo criteria for different formats. If you want to compare DoF, and not the varying criteria, you obviously (really should be obvious, but there you go, needing to have the obvious pointed out to you), you do not use different criteria, but one and the same.

    Different criteria are used in The Real Dof Myth on the assumption that people who use larger formats do so, so they do not have to enlarge as much as when using smaller formats. Which is, of course, nonsense: people use larger formats either because they produce better images when enlarged as much as smaller formats or can be enlarged more than smaller formats. Neither of the two warrants relaxing the CoC diameter criteria.
    So it's plain stupidity of the people who dreamt up The Real DoF Myth to think that the criteria for DoF could be relaxed when the format is larger. People don't use larger formats to end up with the same quality as when using smaller formats just for the pleasure of carrying more weight and using more cumbersome equipment (or whatever nonsense they might have had in their heads when they came up with the different criteria idea).

    But even if it would make sense: i hope you do understand that you can't prove that the Eiffel tower is the same size as a pencil, i.e. that it would be a myth that a pencil is shorter than the Eiffel tower by using a pencil sized unit to measure the pencil, and an Eiffel tower sized unit to meassure the Eiffel tower. Do you?
    (Do you really want to talk about logical fallacies, while proposing it is? :))) )

    So next your "logical fallacy" thing. If you meet someone who wants a pencil to be as big as the Eiffel tower and ask that person why he wants that, you really do think that is the same as asserting that the Eiffel tower and pencils are indeed the same size, or asserting that they are not (or asserting that the Moon is made out of Cheddar cheese, or... )?
    It apparently matters a lot to you that larger formats should not have less DoF. I have asked why twice without getting an answer and will do again. Can you explain how asking why that is would require you to first accept "my premise", and what "my premise" would be?
    Again: you talk about logical fallacies? :)))

    Next the "you're doing it again" bit. What am i doing again? And do you think that "f/8 and be there" not illustrates the point as well as "f/22 and be there"? The significance is really completely lost on you?
    Now, how many hits did you get for "f/1.2 and be there?"
     
  49. Joseph is hung up on the fact that you can achieve a shallow DOF with a small-format camera by using a faster lens (wider aperture). Few medium format lenses exceed f/2.8, whereas f/1.4 lenses are commonplace in small format domain. I don't disagree, but it's an apples-to-oranges comparison. The relationship of DOF to format size is based on using the same relative aperture. Larger formats do offer certain advantages (which Joseph is loathe to acknowledge), and with that come some equipment considerations.
    In a studio situation, strobes are the usual light source. Exposure depends on the ISO and aperture, and is independent on the shutter speed. The lowest ISO on my CFV-16 is 50, which is two stops slower than the minimum ISO on my D3 (200), which wipes out any speed advantage of the D3 lenses. In fact, f/1.4 lenses probably don't belong in a studio anyway, which raises that parameter to f/2 or f/2.8 (maybe slower).
    Using 1000 joule flash heads with a 5-stop turndown, the minimum exposure for portraits is about f/5.6 at ISO 50 - a nice spot for an f/2.8 or f/4 lens. That corresponds to f/11 at ISO 200 - so much for DOF control. I suppose I could use neutral density filters (effect on image quality?), or borrow a set of shoe-popper flash units.
    I never tried apples and oranges together. Now apples and rhubarb - that's a treat!
     
  50. There's been a lot of equipment advanced in the last couple of decades, Al...
    My old 1200J X3200 can be turned down 8.2 stops (1/300 power) and my newer 640 J Einsteins can be turned down 8 stops (1/256 power). Now, replace your D3 with a D3X (we are taking medium format budgets, here) which goes down to ISO 100, and yup, the DOF control is there. When really pressed, a sheet of black lace over the front of the softboxes kills another stop and a half, without measurable alteration of color.
     
  51. The Force 10 is an highly capable flash unit, adjustable over 5 stops in 1/3rd stop increments, with little effect on color temperature. I'm glad you're happy with Paul C Buff flash units, but good ol' Paul promises a lot more than he delivers. 8 stops turndown - OK, if you say so. Even Profoto only does 7 stops, at 5x the price of your Einsteins.
     
  52. Like I said, Al, there's been a lot of advancement in the last few decades. Like you, some companies choose to ignore it. The Profoto is a voltage controlled flash. Just like every other voltage controlled flash on the market, it lowers its power setting by charging the capacitors to a lower voltage, which makes it difficult to adjust down more than 4-5 stops. This also results in a color temperature shift of about 80K for every stop you lower the flash power.
    The Einstein is a really large version of an IGBT controlled flash, like a really large speedlight. There have been a few others on the market. The Broncolor Grafit was one of the first (since replaced by the Scoro) along with the Photogenic Solair. It's not much trouble to make such a flash adjust over an 8 stop range, or more, and hold a pretty constant (within 50K) color temperature while doing it. Power switching electronics improves dramatically each year.
    I've got Einsteins, they deliver as promised. Have you ever actually tried Paul Buff gear, or are you just maligning something without evidence, again?
     
  53. Joseph, it feels like aggressive opinions and preferences are being presented as fact.
    Implying things like MFD users can't realize the benefits of the larger format, more practical ratio, and increase of meg. is a disservice to all the MFD users that produce fantastic, high quality images day-in and day-out. Nothing made by any 35mm company even remotely approached my H4D/40 let alone my current H4D/60 ... in IQ, dynamic range or color fedility. That includes the Canon 1DsMKII, Nikon D3X, and Sony A900 I've used.
    If you meant "in the hands of less experienced shooters", then that would equally apply to the higher performance 35mm DSLRs also.
    The notion that MFD makers can't tap into CMOS technologies because they are niche players ignores the working relationship that both Phase One and Hasselblad have with Dalsa ... who makes large format CMOS sensors for other niche applications, and was/is a pioneer in CMOS technologies.
    So, I still contend that IF CMOS would be a distinct advantage one of the major players would have capitalized on that to capture more market share. For a more balanced idea of the strengths and weakness of each (CCD v/s CMOS), go to the horses mouth and Google Teledyne Dalsa CCD vs CMOS ... paying particular attention to the image quality comparisons and trade offs ... where THEY say CCDs provide the performance benchmarks in photographic, industrial and scientific applications that demand the highest image quality. While there take a look at Dalsa's Feature and performance comparison chart keeping in mind they produce both CCD and CMOS sensors.
    CMOS does allow more features which fits with the consumer and pro-sumer penchant for more sensational marketing promises on their cameras ... balanced with decent IQ. However, for pure IQ the CCDs win hands down ... which is played out in reality by simply observing that all the highest quality makers use CCDs.
    Regarding DOF ... Who cares? ... it is what it is ... and it IS apples and oranges.
    Glad you like your Paul C Buff gear. I tried it and the automotive Fabric swatch bread-and-butter work I slog through was all over the map in color temp consistency ... so, not my cup of tea. No such issues with Profoto.
     
  54. Nothing made by any 35mm company even remotely approached my H4D/40 let alone my current H4D/60 ... in IQ, dynamic range or color fedility.​
    Several FF and even APS sensors exceed both the dynamic range and color fidelity of an H4D-40. It's really not that hard to measure, even without a monochromator sweep (the way I do it). Measuring, on well calibrated equipment, is "fact", Marc.
    I'd hazard to guess that I'm more up on DALSA's various working relationships than you. Citing a 12 year old piece of sales literature is not "fact".
    keeping in mind they produce both CCD and CMOS sensors.​
    True. But keep in mind that they don't produce CMOS that is competitive with anything Sony, Canon, or Panasonic produce. That's only one reason why DALSA was bleeding out when Teledyne bought them a few months back.
    where THEY say CCDs provide the performance benchmarks in photographic, industrial and scientific applications that demand the highest image quality.​
    Actually, no, that's not what they say, at all. What they really do say is that
    "CCDs have traditionally provided the performance benchmarks in the photographic, scientific, and industrial applications that demand the highest image quality (as measured in quantum efficiency and noise) at the expense of system size."
    When people talk about what "traditionally" was, it's a rhetorical device they use to introduce how things have changed.
    "As a result, you can find CCDs in low-cost low-power cellphone cameras and CMOS sensors in high-performance professional and industrial cameras, directly contradicting the early stereotypes."
    Here's what DALSA said that they were going to do 10 years ago when they bought the Philips CCD business...
    "To grow our Company profitability into a $100 million Digital Imaging Solutions business by 2002 and $1 billion by the end of the decade, by being the world’s leading developer and supplier of high performance silicon image sensors, electronic cameras and other semiconductor imaging technologies."
    Now, how much do you think you can believe from these folks? Since you suggested I Google something, I'll make the same suggestion back to you. Have a look at DALSA's financials from the Philips sensor business acquisition to the Teledyne buyout. Once you adjust for inflation, you'll see that they shrank about 60% in the last 10 years. The really scary thing is that, once you adjust for inflation, you'll see that Philips was doing as much sensor business 11 years ago with 60 people as DALSA was doing last year with 600 people.
    "Same old same old" just isn't working any more.
     
  55. After reading this thread, I have to say Joseph is far more convincing. His arguments are logical, thorough, and he actually uses some references as evidence. I was always suspicious of MF advocates, searching the internet for some clear visual proof of MF superiority is like walking through a landmine of false positives and vague "you have to SEE how amazing it is" statements without any actual visual qualification. If someone could link something which proves the superiority of digital MF in pure image quality I would love to see it.
     

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