jack_lam1

As I am doing a research on lens character and the preferred esthetics of lenses, I am increasingly puzzled by the concept of "micro contrast". It is such a controversial topic. Some photographers consider it the ultimate lens character, the holy grail of quality lens. Others dismiss it as sneak oil - a redundant concept that can be more accurately described by existing scientific terms.

The most interesting part is, we don't seem to agree on the very definition of micro contrast. Many believe that it is unmeasurable. They say micro contrast is more than just contrast, sharpness, or resolution. It is the beauty of detailed tonal transition from bright to dark. Some look at micro contrast with a zen-like approach and insist it is something to meant be felt, not measured in numbers. It is the extra oomph. The FORCE. Something that is only seen by discerning eyes.

One can only imagine, a simple blind test can help lead us to a consensus on the definition of micro contrast. But I have yet to see such a blind test on the inter-web. So here it comes.

I shot the following tabletop scene with TEN 50mm lenses. All ten lenses are widely-loved on their own right. They come from a variety of vintage with varying element counts. Some are very expensive cinema lenses. Some are less expensive common lenses. There are no bad lens in this line-up.

Detailed method:

At shot at f/2.8. ISO320. Spot metered on a specific patch of gray on the hat for consistent brightness. All shot with standard color JPEG all-zero settings straight from a LUMIX S1H camera. Shot on tripod with shutter delay. Focus was checked and double checked in live view before each shot was taken. If a slight field curvature in the focal plane is detected, I prioritize for the hat band and the dog. Only very minor tweak in exposure + convert to B&W in Lightroom. Text added in Photoshop. JPEG export quality set to max, sRGB, sharpen=0. Each image is a 3848x1785 center crop from a 6000x3368 image.

To participate in the test, please view each test image in original size.

Please reply with the following:

1) Pick THREE images that possess the greatest / richest amount of micro contrast.

2) Which area of the image is most revealing to you in micro contrast? Why?

3) If you think this is an insufficient test of micro contrast, please explain.

When we have a good number of responses, I will post the model of each lens used.

I know this will inevitably spark some debate on this contentious topic. Please help keep this a civil and constructive experience. I believe our taste for good lens characters are after all, personal tastes. They are as psychological as they are physical. I hope this discussion will eventually help shed light on what our common denominators are when we define a good lens, and we may learn a thing or two from it.

Jack Lam

cinematographer

www.Jack-Lam.com

------------------------

Full composition (downsized, slate blurred out):

http://www.jack-lam.com/-MyFolders/MicroContrast/20200712_S1H_1003928.jpg

Here are the test images:

http://jack-lam.com/-MyFolders/MicroContrast/MicroContrast_JackLam_A_928.jpg

http://jack-lam.com/-MyFolders/MicroContrast/MicroContrast_JackLam_B_931.jpg

http://jack-lam.com/-MyFolders/MicroContrast/MicroContrast_JackLam_C_936.jpg

http://jack-lam.com/-MyFolders/MicroContrast/MicroContrast_JackLam_D_946.jpg

http://jack-lam.com/-MyFolders/MicroContrast/MicroContrast_JackLam_E_951.jpg

http://jack-lam.com/-MyFolders/MicroContrast/MicroContrast_JackLam_F_956.jpg

http://jack-lam.com/-MyFolders/MicroContrast/MicroContrast_JackLam_G_964.jpg

http://jack-lam.com/-MyFolders/MicroContrast/MicroContrast_JackLam_H_969.jpg

http://jack-lam.com/-MyFolders/MicroContrast/MicroContrast_JackLam_i_971.jpg

http://jack-lam.com/-MyFolders/MicroContrast/MicroContrast_JackLam_J_976.jpg

<p>Andrew: Yes I have tried speaking to camera houses and have emailed a couple equipment manufacturers. None of them have products that address to this particular need.<br>

<br />Ellis: I am aware of the Arri dovetail type of quick release you are referring to. It is originally designed for larger 35mm motion picture cameras or today's Arri Alexa.<br>

<br />The problem here is, the motion picture market is transformed by this new breed of small cameras like Canon 5D Mark II or the Blackmagic, but the support accessories haven't caught up with this new trend. Most people are still focusing on making these cameras work like large studio-style cameras by mounting them on full-sized rigs. Full-sized rigs have their benefits, but we shouldn't overlooked the advantage of being able to go small at times.<br>

With the way most rig/cage setups are designed, the blackmagic camera body is semi-permanently attached to the rig. It can take as much as 10-15 minutes to disassemble the whole rig to take the camera body out when one wants to go small. To me that is unacceptable and downright stupid.</p>

<p> </p>

<p>Thanks everyone for the suggestions. So the RRS 16mm clamp is the thinnest one we can think of? Anything thinner than that? Now I don't mind the clamp + plate combo is thicker than 14mm because I don't think I will find one at all. But I do want to find the thinnest clamp available and I mill it down.<br>

Ellis: There are many rail system designed for the Blackmagic Camera, but nobody seems to care to design one that has a quick release.</p>

<p>So this is what I'm trying to do:<br>

<img src="http://www.jack-lam.com/images/promediagears_c40.jpg" alt="" width="984" height="780" /></p>

<p>I need to install a quick release plate between a Blackmagic Cinema Camera and the base plate. Although the camera hasn't arrived, I know from my research that the camera has to be 14mm above the base plate in order the for lens center to be 85mm above the rods, which is dictated by industrial standard for cine-style accessories.<br>

Looks like I need to find a machinist who can help file down the thickness of the clamp. But it need to have an extra long locking screw in the first place.<br>

Any further idea?</p>

<p>For my particular setup, the camera must be raised above its base plate for no more than 14mm.<br>

Can you suggest an Arca-swiss type quick release clamp and plate combo that has a total thickness of 14mm or less?<br>

<br />The plate needs to be around 80 to 100mm long. <br>

<br />If you happen to have the said product with you, can you measure the actual thickness of the item and share with us?<br>

<br />A million thanks!<br>

<br />Jack</p>

<p >I'm referring to theses lenses:<br />Tokina AT-X 828 AF Pro 80-200mm f/2.8 SD<br />Sigma 70-200mm F2.8 EX DG APO HSM (pre-marco, with aperture ring in Nikon mount)</p>

<p>For those of you who owns any of these lenses, can you tell me if they are parfocal?<br>

(Parfoal means: Once focus is set at the most telephoto setting, the focus holds even when you zoom out.)</p>

<p>Also, when you adjust focus manually on the lens, do you notice any image shift, especially when you change direction on the focus pulling? (I heard the Nikon 80-200 AF-D two-ring version does that. When you pull focus from close to far, then you pull from far to close, you see an image shift. That isn't acceptable for video shooting.)</p>

<p >thx</p>

<p > </p>

<p >Jack</p>

<p>Thx Steve for sharing your experience. I know most lens adapters are slightly thicker than specs to allow focusing slightly beyond infinity. That's a good thing because we don't know we have absolute infinity until we go pass it. But I wonder if it will play well with a TC in my case.<br>

<br /> Steve really knows the dilemma faced by today's video shooters. As much as I hope to stay with Canon lenses, the clutched design of their focus rings make them unsuitable for proper focus pulling. Canon EOS lenses are simply no good for cine-style shooting. (Not to mention, I want my lens kit to be compatible with the GH1 too. The lack of aperture ring on Canon lenses disqualify them.)<br>

<br /> Nikon lenses are not ideal either. They focus in the wrong direction. But at least the focus ring doesn't have the clutch that spins beyond infinity and I can mark my distance scale.....<br /> So, anyone else has relevant experience to share?</p>

<p >I have a Nikon 80-200 2.8 lens that I want to use on a Canon 5D Mark II for video shooting.<br>

What type of teleconverter should I get - one that is made for Nikon or Canon? Does it matter at all?<br>

In another word, option 1:<br />Nikon Lens > Nikon TC > Nikon-to-Canon adapter > Canon Body<br>

Option 2:<br />Nikon Lens > Nikon-to-Canon adapter > Canon TC > Canon Body<br>

I figure option 1 is safer because a Nikon-specific TC is optimized for the flange depth of Nikon lenses. But for convenience sake, I'd rather go for option 2 because the adapter can always stay on the lens. I can use the Nikon lens as if it is a Canon one without fiddling with adapters on the field. I can also use this Canon TC for other Canon lenses.<br>

Is it going to work at all? Would I see more chromatic abbreviation or compromise image quality if my TC doesn't match the brand of my lens?</p>

<p >thx</p>

<p>How would you compare the two?<br /> I know Zuiko probably has more color fringe. How do they compare in sharpness and other areas?<br /> I know the Nikon 300/4.5 ED non-IF beat them all, but it is also a very rare item to find.</p>

<p>Here is a little description of my intended use for the lens:<br /> I will use the lens primarily for video. I have a Panasonic GH1 with micro4/3 to Canon EOS adapter. I have a set of primes, mainly Contax Zeiss, adapted to EOS mount. This gives me a set of primes that works for both the Canon 7D/5D and my GH1.<br>

Or would you suggest a 300mm lens made by another manufacturer? (One that is adaptable to Canon EOS) I wanted to buy the Contax Zeiss 300/4.0, but many people say it is mediocre. What do you think?</p>

<p>For video use, I have some concerns that may be not so important to still shooters.<br /> 1) I need nice smooth focus ring with a lot of rotation to pull focus with.<br /> *2) "Breathing" should be minimized - the image shouldn't zoom in and out slightly while pulling focus. I wonder if the IF design of the Nikon does that, since I know the IF design changes the focal length when focus is changed.<br /> 3) The lens and focus ring must be solid and sturdy. I used to have a Zuiko 28/2 with a focus ring that has a very slight amount of play when I switch direction during my focus pulling. It is not at all a concern to a still shooter. But that tiny amount of play is enough to shake the image and it is very noticeable on video.</p>

Joel: Did you sort out the problem with them yet? I'm thinking about buying from them too. For $38 does it come with a pair of glass or just one piece?

Craig: Do you mean you have success just using ONE piece of AN glass and not have the film sandwiched by two pieces of glass? Do you have the film emulsion side down?

I have been using the Spyder2Express with dual monitor setup in OSX.

I find the following work for me. Please correct me if I'm wrong.

What I do is to create a profile for each monitor separately in Spyder2Express.app

1) Set monitor A as the main display in system preference and run Spyder2Express.app

2) An icc profile named "Spyder2express" is created at

"/Library/ColorSync/Profiles/"

3) rename this file as "Spyder2express_monitorA"

4) set monitor B as the main display in system preference, run Spyder2express.app again.

5) Again, a new icc profile named "Spyder2express" is created at

"/Library/ColorSync/Profiles/". Rename this file "Spyder2express_monitorB"

6) Open ColorSync utility and set the current profile to these two files respectively.

Now each monitor are using the profiles created by Spyder2epxress tailor-made for each of them!

I'd like to see how much real world difference do we see by using a Spyder2 instead of the NEC colorimeter.

Anyone has first hand experience?

Oh, nevermind.

I didn't see the previous post before I posted this.

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00OHDJ

I just bought a NEC LCD2690WUXi monitor without their colormeter.

I figured that I can save some money by just buying their SpectraView II

software and use my Spyder2Express colormeter.

I know the Spyder2Express and Spyder2Pro are the same hardware. I hooked it up

and SpectraView can recognize it properly.

My question is, do I miss anything by not using their NEC/Gretag Macbeth

colormeter? Especially for a wide gamut monitor like this?

Joe:

Seeing that you have owned the LCD2690WUXi for more than 2 months now, can you share with us how you like the monitor so far? Is the graininess still bothering you? Do you see much real world benefit in having a wide color gamut?

I'm about to try this.

Can someone who succeeded in making one out of RadioShack parts post the RadioShack part numbers for each item?

That will help save a lot of trouble and confusion.

thanks

I think the hot pixel problem is bigger concern than the banding noise, which can be avoided by not shooting at ISO1600.

(hopefully the horizontal noise pattern will be invisible in B&W)

Can someone who owns the GX100 shoot a "lens-cap" shot at ISO400 at f2.5/0.5sec and email it to me? That will really help me figure out whether I should return my camera or not.

That would be a great help coz I need to make this decision ASAP.

My email: jackcklam(AT)hotmail(DOT)com

The 30 second lens cap shot at ISO1600 is just to illustrate the banding problem in an exaggerated way.

But my main question is: Am I the only one who has this problem? Should I send it back for another exchange?

For a more real world example for the hot pixel & banding problems, I just uploaded a few more pictures on that page.

In the new banding shot, it is not very obvious. But there is clearly some horizontal pattern in the way the noise looks.

I just got my Ricoh GX100 this week and has been playing with it. Most GX100

users are generally happy with its picture quality, and many users call the

noise "film-like" and organic. Some even said its picture quality at low ISO is

"DSLR-class". <br><br>

After closely examining my pictures (pixel peeping?) I found some potential

issues with hot pixels and banding noise. I seldom see any mentioning of these

two problems with the GX100 anywhere online. I know this camera is quite noisy,

and I'm ready to embrace the noise (the rest of my camera arsenal are film gear

with Tri-X/HP5+). But banding noise is simply not acceptable.<br><br>

I am wonder whether these problems are by specs or just because I got a lemon.

Today I returned the camera and exchanged for another one at Adorama, but the

new camera still show similar problems. <br><br>

Please go to this page to see the pictures.

<a

href="http://www.jacklam.net/GX100/GX100.htm">http://www.jacklam.net/GX100/GX100.htm</a>

<br><br>

Any idea? Does your GX100 show the same problem? Is my camera noisier than

yours? (Huh, Maybe the whole batch of GX100 is defective in the same

manner?)<br><br>

Am I expecting too much from a small sensor camera? <br><br>

Just got a new Autocord CdS I. I'm looking for a neck strap for it.

A search on photo.net returns a few threads discussing about how difficult it is

to find a strap that fits the strange strap lugs. Someone suggested that Mamiya

straps might work.

I saw these on ebay. Do you think any one of these would work? Has anyone tried it?

http://cgi.ebay.com/Mamiya-RZ-camera-strap-clips-for-RZ67-RB67-camera_W0QQitemZ150097381452QQihZ005QQcategoryZ3352QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

OR

http://cgi.ebay.com/Mamiya-645-camera-strap-clips-f-M645-Super-Pro-Pro-TL_W0QQitemZ150097016267QQihZ005QQcategoryZ3352QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

thanks,

Thanks A.R. for your great info.

I saw a used Beattie screen for Bronica SQ for sale. Price is much lower than a Maxwell screen (less than half). I know most opinion out there prefer Maxwell screens. What do I miss by going with a used Beattie screen? Is it big enough of a difference to justify the 50%+ extra in price?

A 2nd-hand camera shop owner told me that I should avoid older Beattie screens because their older design suffer from lower contrast and is difficult to focus with. Can someone verify this? I can't find any related info here.

How can I tell an old Beattie screen from a new one?

Thanks everyone for your input.

John: The screen seems reasonably bright for bright outdoor condition. But for dark interior situation I find it difficult to see the shadow area on the screen. Since I don't have a modern bright screen to compare with, I don't have a reference point of how good a bright screen can get.

My original thought was that 40+ years of improvement in technology should give us a much brighter screen. And a screen upgrade will make the camera a much more practical shooter - esp with today's low grain high speed film.

Maybe it is unrealistic to expect from a TLR the type of clarify that I'm used to with a SLR viewfinder, isn't it? Maybe TLR isn't meant for handholding in dark available light situation and I should learn to live with the limitation?

I took Karl's advice and sent him the camera for CLA without adding a Maxwell screen. Let's see if it will get brighter after the cleaning.

Jeff: When you say the autocord screen is on par with your older 500C, and the new hassy screen are beauties compared to the older ones. Does that mean a new hassy screen is much better than the autocord screen?

If that's true, a modern bright screen would be a worthwhile improvement over the original autocord screen. Isn't it?

I just received my Autocord today. I'm ready to send it out for a CLA, but I

want to find out if I should have a Maxwell screen installed at the same time.

<br><br>

Everyone is raving about the improvement of a Maxwell screen on a Rollei. There

is no doubt a modern bright screen can transform a old Rollei and it is almost a

must-have upgrade.

<br><br>

But what about the Autocord? Some people say it is good to have the screen

upgraded. At the same time, many people say the original autocord screens are

clearly brighter than the Rollei's.

<br><br>

I emailed Karl Bryan (a pro repairman specialized in Autocord) and asked for his

opinion. That's what he said:

<br><br><br>

<i>

"I have found that the Beattie and Maxwell screens are grainy compared to the

Autocord. Yes, the screen is bright but the large Fresnel lines bug me. The

Autocord Fresnel lines are smoother and almost not visible. If you want to see

a truly bright screen that has super fine Fresnel lines, check out an Ikoflex

Favorite. The Favorite screen looks like a bright ground glass screen rather

than a ground glass screen with a Fresnel lens behind it. As far as inferior,

what are you defining as inferior. The design parameters used by the engineers

for the screens were not the same. Beattie and Maxwell aimed at bright screens

for large format cameras where you are shooting at f/32 or f/64. The reason

they wanted a bright screen is the focus of some large format lenses shifts as

you stop down and most large format camera users are fanatical about focussing.

So without a bright screen you ended up staying under a hot focus hood in the

hot sun until your eyes adjusted and then tried to focus. It was later that the

screens were made for TLRs, due to requests from Rollie users because Rolleiflex

didn't know how to make decent screens. The Autocord/Diacord screens were

designed specifically to emulate a ground glass screen but to be brighter. It

was their way of setting themselves apart from the horde of Japanese TLRs in the

50's and 60's. Yashica TLR screens are bright but grainy but Yashica got away

with it because they undercut the other manufacturers in cost.

<br><br>

I would recommend trying the Autocord screen before spending the money on a

Beattie or Maxwell screen."</i><br><br>

So now I just received the camera and have spent some time with it. The screen

is decent and workable, but I still wish it could be brighter. <br>

<br><br>

Here are my questions:<br><br>

1) How much brighter is a Maxwell screen?<br><br>

2) Do you find the pattern on the fresnel lens of your Maxwell screen to be

distracting?<br><br>

3) I'm new to TLR. Is the extra brightness beyond the original autocord screen

going to help much in the operation of the camera?<br><br>

4)Some people prefer a plain matte screen and some prefer screens with a split

rangefinder in the center. What's better for TLR? Is it simply a matter of

personal preference?

<br>

<br><br><br>