Does stepping down beyond f/8 on a crop sensor camera soften the image?

I read in this post that stopping down to say f/22 on a crop sensor camera can soften the image... if so, is the resulting softening drastic? What about landscapes where you want to get everything to the horizon as much in focus as possible... is that still achievable with f/8 or am I missing something?

NeoDSLR wrote in post #9417608
I read in this post that stopping down to say f/22 on a crop sensor camera can soften the image... if so, is the resulting softening drastic? What about landscapes where you want to get everything to the horizon as much in focus as possible... is that still achievable with f/8 or am I missing something?

It depends on the lens. Each one seems to have more or less diffraction depending on lens quality.

You can google for more info
http://www.luminous-landscape.com …eries/u-diffraction.shtml

For landscape, I keep my 5D between F8 and f11 for best results with my lenses. But you really need to test each of yours for yourself to see where the sweet spot is to get the most depth with the least diffraction.

Just like everything in photography these days, this phenomenon seems to be taken way out of proportion.

Diffraction is an issue if you are one of those that just has to have the peak sharpness of your lens. What you have to balance that against is: can you get the result you need from f/8 or f/5.6, or do you need to go to f/22 or f/32 to get the image you need?

I'm in the camp that says get the image you see in your head. Period. Yes, of course, if you can get that image while optimizing image quality, do it. However, I can not see turning away from an image just because I'm worried about some silly thing like diffraction. The image below was shot at 190mm and - GASP! HORROR! - f/29. I have a 20x30 hanging in my store, and you can't tell at a normal viewing distance. Could it have been sharper? Sure, but it would have taken many more shots and much more time in Photoshop layering the images to get the same DOF.

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f-14 f-16 are about the limit to where you can's see a difference, at least to my eye.
f-22 a difference can often be seen, to my eye it caqn start to look grainy or pixelated, less sharp and finely detailed.
Typically if shooting a landscape with nothing in the close foreground f-8 to f-11 is what I use.
If there is something very close but not within 3 or 4 feet or so I will use f-16.
There are depth of field tables you can use for reference on the net.

Of course, as Ben points out you can ignore diffraction and shoot at whatever settings create the image you want to create.

However, seeing as your post explicitly stated landscapes were your interest, I based my response on my experience with diffraction in the landscape world. Taking closeup shots of flowers may in fact produce different results and may require different solutions.

Diffraction is absolute, and related not to FL or other lens characteristic, but simply determined by the f/number size of the aperture. Due to the fact that a small format has to enlarged by a greater magnification than a large format, the diffration simply becomes visible at the higher magnification factor which is required for the small format. Lens diffraction is always lowest at max aperture.

But other factors do enter into lens performance, and that is the ability to hold contrast at a certain f/number, and that is the MTF performance of the lens, which does vary by len design. Poor contrast at a certain f/number, in addition to lens diffraction, both combine to determine ultimate lens performance in terms of ultimate detail resolution of the lens. And that is why most lenses perform optimally about 2 EV smaller aperture than max aperture, in spite of the fact that diffraction is lowest at largest aperture.

As others have pointed out, sometimes DOF is more important than increasing visibility of diffraction at small apertures.

WaltA wrote in post #9417971
Of course, as Ben points out you can ignore diffraction and shoot at whatever settings create the image you want to create.

However, seeing as your post explicitly stated landscapes were your interest, I based my response on my experience with diffraction in the landscape world. Taking closeup shots of flowers may in fact produce different results and may require different solutions.

But the closeup of the flower shows that good detail can still be retained at small apertures; something good landscape photos can benefit from.

Perhaps I did let off a bit of steam about it, and didn't really answer the question at hand. As stated elsewhere in this thread, depending on if something important is in the foreground, you can use a moderate aperture anyway and get great results with little to no effect from diffraction. However, if you're like me with my landscapes, placing some object in the foreground that needs to be in focus is common place, and I often need to use f/16 or smaller to get it all in focus properly.

Thanks for all the useful replies. I just compared some photos I'd taken of the same scenes, some at f/7.1 (P-mode) and again at f/22 (P-mode but adjusted aperture) and the f/7.1 pics are definitely sharper across the lower two thirds of the image. The f/22 image shows marginally better sharpness in the top third but not drastically so. Interesting stuff!

so the "sunny 16" rule is not advisable?

The diffraction cutoff frequency

johnj2803 wrote in post #9429839
so the "sunny 16" rule is not advisable?

Um... "sunny 16" is not about shooting at f/16. It's a rule of thumb that lets you calculate exposure settings in direct sunlight.

gcogger wrote in post #9431428
Um... "sunny 16" is not about shooting at f/16. It's a rule of thumb that lets you calculate exposure settings in direct sunlight.

oh ok... i thought it was shoot at f 16 with the shutter speed the inverse of the iso... or any variation of that (adjusting all 3 accordingly). technically shooting at f16 in direct sunlight... stopping down the aperture with the corresponding inc/dec in iso and shutter.

The sunny 16 rule is an easy to remember starting point for exposure but it is meant to be used such that you start with the aperture, ISO and shutter of 1/ISO and then adjust to suit the shot.

Example - bright day taking a portrait. start at f16, ISO 100 and 1/100. Portrait suggests wide aperture for blurred backgrounds so make that f2.8. This means that the shutter speed needs adjusted accordingly to maintain the correct exposure ie 5 stops down making the shutter speed 1/3200

k got it that is what i was talking about too.