D2x Images-- Let's try this again

[bill c.]

OK, back from assignment, let's try to post some of those D2x images

again. Also, most of my review was cut off, some sort of forum glitch

(can't even post replies to the original thread).

 

Let's get the "flying seagull" images out of the way first. Here's a

low-res of the overall frame.

 

(to be continued...)<div></div>

[bill c.]

Now here's a very tight detail crop of the eye of that seagull, with absolutely no manipulation. Original was a JPEG.

 

To be continued...

[bill c.]

After taking a look at how that detail shot came out after being posted, I'd like to point out that virtually none of the JPEG artifacts that I saw around the seagull's beak was visible in the original image. Those may have come from the forum's storage algorythm.

 

The VR on the 70-200 2.8 did an incredible job of holding the image stable as I tracked the bird, and the autofocus performed equally as well. That was with the 2x converter attached, and the data says that the focal length was about 180mm. I've noticed that the data readout does take the teleconverter into account when determining the focal length of the lens when the image was taken.

 

Aside from the problem I have already posted about (the intermittent short in the I/O port), the camera is an awsome performer. Comparing it to scanned Fuji Provia slide film, it appears to be just below the Fuji's resolution, HOWEVER, I do not have the same exact lenses for a true direct comparison (the slide film is old work, haven't shot 35mm transparencies in I don't know how long).

I sold the fourth image I ever took with the camera, a test shot with the 70-200 of my dog sitting on the floor in front of me. Now, you have to realize that I have a very unique brown dog with the most incredible blue eyes you have ever seen, and I have them peering directly at the camera. The eyes are in focus and sharp, thanks to the VR, and the rest of the dog's face is blurry. It was purchased by a local ISP provider for an ad. Twenty frames later, a shot of three sticks poking out of the surface of a glassy lake was sold for the cover of an Eastern medical arts magazine.

 

On the other hand, several frames of the King of Norway holding a wreath at the tomb of the unknown soldier were corrupted on output, but it was corrected by downloading directly from the card. The problem cost me a couple of hours of time, which is deadly in the PJ business.

 

The camera is HEAVY! I carried it on a 1.5 mile walk around the lake behind my house this a.m., in a case with the 70-200 attached, and my shoulder is still hurting. The lens did add significant weight, but such a thing doesn't happen with the D70. The case has significant padding on the strap, and I was wearing a thick jacket, but it didn't help.

 

In an earlier thread, someone giving a review of the camera after having seen it at a show stated that the salesperson said that in high-speed mode a 600mm lens would turn into a 1200mm lens, and therefore came to the conclusion that the salesperson was ignorant. It wasn't the salesperson. High-speed crop mode cuts the sensor down to half the size of a 35mm frame. Apparently the author wasn't very familiar with the camera's features. Amazing that someone with so little knowledge and experience with such a complicated piece of equipment would feel qualified to spout off with authority on the subject.

 

Informal tests indicate that the HS crop mode is a tad sharper than the D70, which I also own. If I get enough work done today, I'll try and run a more definitive test with similar fields of view for direct comparison.

The D70, BTW, is giving me somewhat inconsistent results in terms of sharpness. Yes, I'm aware of the potential back-focus problem, but it seems more to be in the algorythm. With the 70-200, the images are sometimes astoundingly sharp, but with wide-angles the percieved resolution can be disappointing.

Again, testing, testing, testing, but the work has piled up and I spend far too much time on photo.net!

 

Best of luck, and happy shooting. -BC-

[aeiffel]

Cropping a shot taken with a 600mm doesn't give you a true focal of 1200...

[greg s]

A crop is a crop, and 600mm is 600mm. There is no confusing the two. -Greg-

[lex_jenkins]

Oh, yikes, here we go again with the crop factor nonsense.<p>

<p>

From the Zörk (Zoerk) website, maker of various lens adapters:<p>

<p>

=================================<p>

<p>

"Understanding focal length and image size <p>

<p>

Lenses of a given focal length produce <i><b><u>the same size image regardless of camera or film format</i></b></u> (emphasis mine). However, because of the cropping effect of a smaller format relative to the original format for which a lens was designed, a standard medium format lens ? such as 80 mm, becomes a short telephoto lens on a 35mm camera or a medium telephoto on a 1.5 multiplication factor digital body. What is important to remember is that each focal length has a distinct perspective or 'look' - the rendering of spatial relationships (such as geometric compression or elongation) and depth-of-field at a given aperture. These effects are format-independent (i.e., an 80mm lens, while appearing "normal" on a medium format camera, will produce the same perspective as an 80mm "short telephoto" on a 35 or full frame digital camera). For this reason, it is more appropriate to describe the effects of a lens in terms of cropping or image size relative to format than "magnification factor," which is commonly used in comparing 35mm lens coverage with APS-size digital sensors."<p>

<p>

=================================<p>

<p>

It DOESN'T MATTER. All that matters is *effective* focal length relative to the film/sensor format.<p>

<p>

Riddle me this: Let's say a lens manufacturer somehow miraculously manages to design a lens that satisfies everyone's perception of what a "true" 1200mm is for the current Nikon dSLR sensors.<p>

<p>

So... what focal length would it be on a 35mm Nikon?<p>

<p>

You folks are persistent in misplacing emphasis on crop factors instead of image circles. An 80mm lens is an 80mm lens is an 80mm lens regardless of whether it's on a dSLR, 35mm, medium format or large format. Assuming it has adequate coverage for all these formats, the lens *is* effectively a 120mm focal length with 1.5x dSLRs when compared with 35mm; *is* effectively a moderate 80mm telephoto with 35mm; *is* a "normal" lens with 6x6cm; and *is* a wide angle with large format.<p>

<p>

I don't understand why this is so difficult to comprehend. If necessary I'll be willing to lend my Yashica 635 TLR to anyone who still harbors doubts and misconceptions. The 80mm lens is a normal lens when 120 is loaded up and - wonder of wonders - a moderate telephoto with 35mm.<p>

<p>

To demonstrate, set up a 35mm camera with 50mm lens on one tripod and the Yashica 635 loaded up with 35mm film on another tripod, both side by side.<p>

<p>

The only constraint is that when the camera is oriented normally all 35mm frames will be vertical. It makes a nice portrait camera with 35mm because there's no need to *crop* off the extraneous areas often seen on 6x6cm negatives.<p>

<p>

If the phrase "crop factor" is going to be so persistently bandied about here then there should be a forum requirement that any and all references to Nikon 35mm cameras include the disclaimer that the 85mm f/2 Nikkor is not a "true" telephoto but is simply benefitting from the "crop factor" relative to medium format.<p>

<p>

Even 8x10 film enjoys the benefit of a huge "crop factor" advantage when a "normal" lens for billboard sized film is adapted to the mere large format camera. Why does no one ever fret about this on the Large Format Forum? (Other than the fact that such a lens probably doesn't exist.)<p>

<p>

Let's just agree on an arbitrarily determined hypothetical upper limit for the maximum size of any capture medium, whether a sensor or film. Billboard size is good. Then we can enjoy making dismissive remarks about the "crop factor" with banquet cameras, 4x5, 6x9, 35mm, dSLR sensors, 110 film, microfilm, ad nauseam.

[loreneidahl]

Lex - good points!!

 

AND it gets even more fun in Large Format where there are specific lenes for wide angle and for Telephoto, the focal length of lens is not used to determine if a specific lens is wide or tele.

[lex_jenkins]

Yeh, at least we don't have to deal with lenses measured in inches.

[ky2]

If we could get a hold of an infinite-resolution capture-emulsion/imaging device, all we would really need is the ideal 1mm lens with infinite cropping scalability :)

[greg s]

"An 80mm lens is an 80mm lens is an 80mm lens regardless of whether it's on a dSLR, 35mm, medium format or large format."

 

My point exactly.

[vivek iyer]

Yes, the crap factor does not change the focal length nor does it change the magnifications involved.

 

They remain the SAME.

[aeiffel]

HSC mode sensor size vs 35mm = 1:2<br>

At f8 in 35mm format, for the same focal length and to reach the same DOF, your aperture will be 8/2 = f4 in HSC mode. So with a given lens, if you move so as to get the same view with both formats, you'll end up with twice the DOF in HSC mode. Or to put it differently, using the same focal, same aperture and shooting from the same place, the DOF will remain the same if you crop the 35mm in order to get the same view. So "crop" sounds better to me. There's really nothing dismissive here, I see the extended DOF as great way to maintain fast shutter speeds and good sharpness. But it also means it'll be more difficult to get OOF with slow lens.<br><br>Pros and cons as usual.

[ky2]

Arrrgh... "you'll end up with twice the DOF in HSC mode" ... which now would require an enlargement twice as much instead of 1.5x, dismissing your DOF-extension claims...

[ilkka_nissila]

Yaron, at the same aperture, the same field of view, and print size, a smaller sensor will yield larger depth of field. This is very, very basic stuff.

[bill c.]

YO! GUYS! WE ALL KNOW WHAT THE FREAK I'M TALKING ABOUT HERE IN TERMS OF THE CROP FACTOR! You're splitting hairs. Effective focal length equivalents have different effects in each format because the magnification factors are different and the resulting compressions are different. Let's call it "equivalent field of view."

 

The previous poster I referred to still thought that the crop factor was 1.5x in high-speed mode. He didn't seem to be aware that the crop factor could be changed to 2x.

 

As for your previous writings on the subject in this thread, you all are incredible. I'm in absolute awe of your technical knowledge. You people are mental giants. Now LET'S MOVE ON!

 

-BC-

[fourfa]

someone had to say it

[walterh]

Well Vivek said it :-P

 

"CRAP factor" - I agree crop factor is CRAP factor .

[jim_gifford]

Bill, I hate to interrupt the cheery debate on terminology, but I'd like to congratulate you on a very nice gull photo, and thanks for working to bring the forum a taste of what your new D2X can do.

 

The "600mm vs 1200mm telephoto" debate is a hot one for purists because the small sensor (compared to 24mm-by-36mm) will give DSLR images some, but not all, the characteristics of images taken using longer focal length glass on a film body. Field of view is a match because of the cropping. Perspective is a match because of where the camera sits relative to the subject. Depth of field is not a match, for a given aperture and field of view, and that gets more obvious at longer focal lengths. And so on a so forth.

 

The differences leave some people apoplectic at those who use imprecise language and say "The even tighter HSC mode turns a 600mm into a 1200mm!"

 

I do understand the value of precise use of words... and I understand that editors' blood pressures can and do spike in arguments over whether the "S" between Harry and Truman needs an accompanying period so it will not LOOK like a typo even though it is NOT a typo... and, even so, I just don't get my undies in a knot over how people describe DSLR focal length issues.

 

Be well,

[geof_grieble]

At least we finally have Nikon camera with enough resolution to allow cropping. That it can

be performed in the camera (using the HSC mode), or in Photoshop, gives the user added

flexibility, and there is nothing wrong with increasing user flexibility in my mind.

Regardless, I think the real point of the HSC mode is to achieve increased frame rate. I've

cropped all of the pictures <A href="http://www.pbase.com/ggrieble/florida_weekend">

here</A>, mostly because I only brought my 70-200 and TC-14E. The hawk is an

extreme crop that would have been impossible to achieve with my D100.

[vivek iyer]

Geoff, Many thanks again for the pics.

 

The downside of the crop mode or extreme cropping appears to be lack of sharpness. Since the focal plane is often not on the subject, cropping may not be very useful under conditions where a wide open lens was used. The two bird photos (Egret and Hawk) do not look sharp to me at all. The gator is alright, can't say much about the Rocket (I suspect the launch was quite far away from where you were standing).

[bill c.]

One of the advantageous things I've discovered about the crop mode is that it allows me to see what's coming into the frame or what's going on just outside of it. That's helpful with sports and moving wildlife. While it's OK for web work, newspaper assignments, and perhaps for glossy magazines if it's used small, basically all it does is allow for higher-speed shooting and cut down on wasted memory space if the anticipated crop exceeds the throw of my lens.

 

I plan on doing comprehensive tests between the crop mode and D70 either this evening or tomorrow.

 

Happy shooting. -BC-

[geof_grieble]

Vivek,

 

Both looked okay (sharpness wise) to me before I uploaded but I do agree the Egret looks

soft for whatever reason (but I don't like the Egret shot because of the extreme contrast

either). I think the Hawk is okay though.....In any event stopping down the lens would have

helped - this is really the first time I've used the TC-14E with the 70-200. If I marry those

two again I am definitely going to stop down a bit. And yes, the rocket was far away...the

gator must have watched because he/she was facing the right direction and just down the

causeway a bit....:)

[lex_jenkins]

"The downside of the crop mode or extreme cropping appears to be lack of sharpness."

 

===============================

 

Yeh, same with the wonderful little Pentax 110 SLR, one of the best photo toys ever invented.

 

So what's the point? Who doesn't already know that *effective* focal length changes according to the size of the film format/sensor size?

 

Chant the mantra with me: Image circle, image circle, image circle. That's the only relevant limitation. Lather, rinse, repeat until it soaks in.

 

There sure is a bad case of 35mm-centricism here.

[vivek iyer]

Geof, Thanks for the reply. It makes sense now.

 

Lex, Go over to the Minox forum (AKA Martin Tai) and try this. Those tiny little cameras are something else when it comes to sharpness.

 

The Pentax 110 (I have a set from several years ago, BTW), is a neat little SLR but the lenses aren't that great, IMO.

 

Olympus Pen is the king when it comes to this. Their lenses are superb. You can actually make some useful photos with the Pen F.

[lex_jenkins]

Yeh, Vivek, I've browsed a couple of sites devoted to Minox and ultra-miniature film use. They do seem better able to make sharp photos because the film train is more secure.

 

The problem with even the best 110 cameras - and there were a few - was the relatively floppy arrangement of the paper backed film in those cheapo plastic cassettes. Without pressure plates to ensure consistency those cameras were never going to be tiny equivalents to a competent 35mm SLR. But the Pentax 110 was fun.

 

I remember the Olympus half frame cameras when they were new. A couple of my photo class instructors had them when I was a kid. They had the "way cool" factor and made moderate sized enlargement that were entirely comparable to our full size 35mm shots.