Ever Wonder Why Images Shot at f/22 Are Softer Than f/8?

You may have noticed that as you stop down your lens, your images become sharper at first, but after a certain point, they actually become softer. Here is why no matter what lens you use, eventually, you will experience softness issues as you use narrower apertures. 

Coming to you from ZY Productions, this great video will show you the concept of diffraction and why it causes softness issues at narrow apertures. The thing to remember about diffraction is that it is a physical phenomenon, and thus, there is no way for manufacturers to get around it. Thus, it is important to be aware of it when you work at narrower apertures. You might be tempted to stop down to something like f/22 for better depth of field across your image or a similar f-stop so you can use a lengthier shutter speed for a long exposure. Instead of dropping your aperture to such an extreme f-stop, consider using a technique like focus stacking or calculating the hyperfocal distance or adding an ND filter if you need to extend your shutter speed, particularly if sharpness is the most important aspect of your images for you. Check out the video above for the full rundown. 

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18 Comments

Michael Comeau's picture

I actually never noticed this until the Internet told me it was important.

Nitin Chandra's picture

Nice general one. In practice, it can be quite different. Depends a lot on the light and subject and to what level diffraction is acceptable.

Deleted Account's picture

Exactly. If you're shooting a landscape at 200mm, you need to be way beyond f/11 if you want everything in focus. Diffraction does a lot less damage than a shallow depth of field sometimes.

Eric Robinson's picture

As the man says shoot at f8 and focus stack. Or on the other hand is what you shoot at f16 acceptably sharp? For landscapes is pin sharpness as important as it is in wildlife, where sharpness will make or break an image. There are no real hard and fast rules in photography sometimes sharpness is crucial, sometimes it’s not.

Nitin Chandra's picture

It all depends on a variety of factors...I have some macros here, check out the EXIF and see :)

https://www.flickr.com/search/?user_id=96392478%40N06&sort=date-taken-de...

Eric Robinson's picture

Great shots very nice style...

Troy Straub's picture

Most of the video seemed like decent enough info to me, but not sure why he said those cat shots were at f4 and f8. if that second one was at 8 he straight up missed focus.

Matthias Kirk's picture

"...ASSUME this is how much softening... at f/4..."

Troy Straub's picture

I shoot macro on micro 4/3. I usually shoot at F8 but if I need the DOF I'll go to 13 or 16 and I'll take it to 22 if it's a flower or something that is somewhat soft anyway . You definitely loose some sharpness, but sometimes it's better to have enough of the subject in reasonable sharpness than a sliver or razor sharpness.

Jakub Valovič's picture

Shots of cats seems to be quite unrealistic - even if he made a mistake and one was at f/8 and other f/22, there is no way for it to be that soft.
Important thing not to forget about is that longer focal lenght will give larger physical aperture at given f stop.

Anyway, from my experience I have never noticed any disturbing levels of diffraction using f/22 with 35mm lens (shortest I own).

Just me's picture

Shooting landscape with 1APS-C 1-16 Tokina and the softness starts at F10..
Best sharpness are F8

Before F8 , it's also getting softer.

All lens have their sweet sharpness spot. It's never on the bottom or the end of the aperture range.

Malcolm Wright's picture

Lens reviews I've watched (particularly some of the 300 odd from Christopher Frost) have most lenses sweet spot at f8. Some still improve to f11 although a lot don't.
Although defraction can set in later depending on the camera sensor. He uses a mix of full frame and crop sensors from Canon, Sony and sometimes Nikon and Fuji for his reviews.
With the sweet spot usually around f8 for most lenses it goes to prove that most lenses sold have an apperture range to allow photographer's artistic licence.

Stuart Carver's picture

I find a lot of people get caught up in this diffraction debate and sometimes unnecessarily.. Focus stacking is the obvious solution but if you dont want to get that deep into your edit then using f16 etc is fine in most cases when not viewing a shot at 400%

Mike Dixon's picture

It really does depend a lot on the lens. My Canon EF 100-400mm f/4.5-5.6L IS II USM is really good at f/22, but I've had other lenses that I wouldn't take past f/11 unless I needed a starburst.

Joel Manes's picture

Sharpness is highly overrated. I've never seen a really good photo and thought that it would be better if it were sharper.

Timothy Roper's picture

How, then, did Group f/64 become a thing in the early 20th century? Seems like, if f/22 is bad, shooting at f/64 isn't really possible due to diffraction (or at least not to get the sharp results the group was all about).

Jakub Valovič's picture

They were using 8x10 cameras for which standard lens (about 43mm full frame equivalent) is 300mm - that gives larger physical aperture at given f stop; i.e. f/22 on 43mm lens gives aperture with diameter of 1,95mm while on 300mm lens its 13,64mm. So f/64 on 300mm lens is 300/64=4,69mm, equal to roughly f/10 on 50mm lens.

On the other hand, Edward Weston's famous photographs of pepers, cabbages etc. are rather soft from diffraction, but he used nearly pinhole sized aperture to get the depth of field he wanted.