1Ds Mark III limited at f5.6

I have been kicking around the idea of getting a 1Ds Mark III or the 5D II. As I move to more studio ISO 100/200 flash contrived compositions I want a file that is large enough for me to work in Photoshop to achieve different looks and room for cropping. I shoot sometimes at f8 to get the best out of the lens but look at what this link shows:

http://www.openphotogr​aphyforums.com/... .../showthread.php?p=4​6107#post46107


Should I look at the Mamiya 645AFDIII with digital back instead? It seems Medium Format is the way to go for studio work both inside and outside.

Many photographers use the 1DsMKII or III for studio work with excellent results. And f/8 isn't always the sweet spot of a lens. Certainly you're going to run into diffraction issues as you stop down the lens, but how big an issue it becomes depends on the degree of enlargement you intend for the final image and the amount of detail required. Certainly the MF backs can offer some superb detail, but it comes at both a financial cost and a convenience cost. It really depends on what you need.

The first thing that comes to mind is that I don't see any indication that he adjusted for the actual aperture value of the lens at 3:1. The MP-E 65 is nominally an f/2.8 lens, but at 1:1, your true aperture is really f/5.6, not f/2.8 since you need to include the 65 mm of lens extension as well as the 65 mm of the focal length in the calculations. At 3:1 the extension is 4x the focal length; your effective aperture is f/11 when the lens is wide open. So his f/5.6 example is more closely comparable to your using a lens at f/22 than f/5.6 under normal (non-macro) conditions. At 3x magnification it's not even possible to get a true f/5.6 or f/8 aperture. For more on this, take a look at this photo.net write-up. You'll also see it alluded to in this post in the thread you linked. So I don't think you need to worry about shooting at f/8.

Jon wrote in post #5835940
So his f/5.6 example is more closely comparable to your using a lens at f/22 than f/5.6 under normal (non-macro) conditions

Okay, thank you. I was getting very worried there for a minute!

And if you are really worried about studio shots, look up 'TheAztech' -- he currently uses a 5D in a studio setup, and the images are on the money!

I agree with Jon. As the writer of that article points out, the MP-E 65 shows the effects of diffraction much more than other lenses, which is why he used it. In normal use with regular lenses (as opposed to a highly specialised piece of kit which isn't representative of normal studio work) you won't see any significant diffraction problems below f/11 with a crop body and f/16 with FF.

Of course, medium format will always be a better studio format than 35mm / FF or a crop. Film or digital, the basic premise is still that the larger the film / sensor being used, the better the quality of the results. That isn't going to change, so yes you will be better off with a Mamiya 645.

Unless you are making extremely large prints though, I doubt that you would see a significant IQ difference between that and a 1DsIII. The 1DsIII will produce excellent quality results and diffraction won't be an issue at f/8 - f/11.

The point is that the only reason the MP-E 65 seems to show the effects of diffraction more than other lenses is that the indicated aperture isn't the aperture value you're actually shooting at. If you shoot at f/11 with a "regular" lens at "normal" magnifications, I'd expect about the same results as the MP-E 65 gives at indicated f/2.8, which is a real f/11 at 3:1 mag. f/ number at high magnification isn't focal length/aperture diameter; it's (focal length + extension)/ aperture diameter.

All I can say is I have a 1DsMKIII and I don't worry about diffraction until around F/16 and then only a minor consideration. On the rare occasions I have shot a higher f-stop diffraction does start becoming an actual factor, but depending on what you are shooting go for what you need.

Since I usually use my 1DsMkIII in the studio though, I tend to shoot at f5.6, which is the sweet spot on two of my three most used lenses. The other has the sweet spot between f2.8 to f4. But, I have been doing some product shots lately and needed to shoot at f8 or f11. No problem.

In the studio use the Aperture that gives you the Depth of field that you need.

Jon: Slightly OT, but can you explain why it is that the effective aperture of the MP-E 65 at f/2.8 is f/11? I assume that the lens is designed sort of like a normal 65mm lens with extension tubes to raise the magnification (which is why more light is lost when the lens is set to a higher magnification)?

edit: Just read your last post and realized that you just answered my question =_=... So that means at 1:1 magnification, there is still an extension included?

My 24-70 and 70-200 2.8 IS are best with micro-contrast at f11 on the 11 MP 1Ds...