I disagree. Shooting at small apertures like f13 and f16 reduce IQ due to both diffraction and also due to the fact that most lenses have peak sharpness at f5.6 or f8 and then decline steadily after that.
Take a look at Lloyd Chamber's post on diffraction effects on his website.
I agree that there is a balancing act and that sometimes you need to stop down that much to get enough DOF to cover both close subjects and far subjects but you are doing it at the price of reduced IQ.
Also, if it is a subject with not much fine detail then it won't show as much so then it maybe a wise tradeoff.
Another option is to shoot multiple focus bracketed shots with a shallower aperture to max IQ and then use HeliconFocus to put them together.
You won't maybe notice the difference in web size shots but you will if you print large enough.
And I don't think there is any way in post processing to get back the fine detail lost when shooting at very small apertures.
You're right Wayne. I believe the differences are small enough for me to live with, since I have numerous large prints from digital f16 images that are fine, and my LF work is often f16 to f32. I'm trying not to think at the molecular level.
Fred, I believe, so far, that my 21ZE and 35ZE are of similar quality. I know you enjoy large landscapes, so I suggest you give the 21 a try. You'll have to deal with convergence if your camera is not square to your subject (as always with wide angles).
tsdevine wrote:
I'm sure holes will be poked in this, but FWIW here are some corner comparisons. Shot with 5D, tripod, MLU, etc. Focus was on the center of the frame (the building), so some of the corner softness may be due to field curvature. Processed through DxO with lens corrections turned off (only matters for the 16-35 mk II.) I can't remember if sharpening was turned off or set to default. Crops are of upper left corner. Left capture is with the 16-35 mk II, right is with the Zeiss 21mm Distagon.
Don't know if this is helpful, but figured I'd post....Show more →
Not really sure it is all that helpful, the crops are not from the plane of focus. That tree branch appears to be well in front of the building.
Wayne--whilst I don't disagree with your assessment, I've noted myself that "diffraction limited" photos sharpen up better than "abberation limited" photos. Having gone through the theory as well, it makes mathematical sense (well, deconvolution of diffraction is more predictable, so to say)
But yes, more or less it's best not to stop down one's aperture more than absolutely necessary.
Jeffrey--I'm sure you know, but f16-f32 on a LF camera (4x5 I assume?) is nowhere near as deleterious as f16 on a 35mm camera. Not only are you not aerially magnifying a 4x5 print as much as a 35mm, but the transition between "abberation-limited" and "diffraction-limited" resolution happens much later, especially when movements are involved. It's nigh impossible to make a LF lens as well corrected as a 35mm lens due to the dramatically larger projection.
Daniel Heineck wrote:
Wayne--whilst I don't disagree with your assessment, I've noted myself that "diffraction limited" photos sharpen up better than "abberation limited" photos. Having gone through the theory as well, it makes mathematical sense (well, deconvolution of diffraction is more predictable, so to say)
But yes, more or less it's best not to stop down one's aperture more than absolutely necessary.
Jeffrey--I'm sure you know, but f16-f32 on a LF camera (4x5 I assume?) is nowhere near as deleterious as f16 on a 35mm camera. Not only are you not aerially magnifying a 4x5 print as much as a 35mm, but the transition between "abberation-limited" and "diffraction-limited" resolution happens much later, especially when movements are involved. It's nigh impossible to make a LF lens as well corrected as a 35mm lens due to the dramatically larger projection.
I agree with you and that is what I meant by sometimes using small apertures to get enough DOF, basically trading off loss of IQ due to diffraction vs. gain in DOF for the scene if you need it.
Magiclight: As well as the sharpness advantage, the way the 21ZE "draws" was an eye opener for me. Just magic!
I also have the 24L II, and it is sharp also, but as magiclight has eluded to, the 21ZE ability to "draw", is amazing. I have taken shots, from similar sites with the 24LII and the ZE 21, the ZE 21 ability to extract, colors,depth and feeling is very different. It is not just the sharpness. With PP a lot of the minor advantages in sharpness are over shadowed. The "drawing" ability of the lens cannot be duplicated IMHO.
I've shot the 35/2 at about f/16 and really haven't noticed much of a sharpness trade off, looking at the image on a 24" computer full screen, I am quite pleased... I haven't printed yet, but when I do print it rarely goes beyond standard magazine sizes.
Adamwilde: I think you have you have hit the point. Depending on your target output, there are so many different ways of processing. I find for large prints A3+ sizes, it so different, that what we see on large calibrated monitors, where there so many varying perspectives deciding the ultimate IQ of lenses.
Daniel Heineck wrote:
I've noted myself that "diffraction limited" photos sharpen up better than "abberation limited" photos.
yes, very true when a lens has "lateral colour", normal CA though is less of a problem. I also agree with Jeffrey, with a good lens/camera you can stop down quite a bit before the print gets visibly softer and even then the quality is as good as we can wish for.
