When is it a good idea to take Fstop up to like 22?

[barrett14]

I am new to photography so I am still trying to learn the ropes. From what I gather, having a low f/stop of say, 2.8 is beneficial because it lets you shoot in low light situations with a higher shutter speed, and it also increases your depth of field.

I initially thought that when shooting landscapes, it was best to use f/22 because it got the most stuff in focus, but then I heard that f/11 is the "sweet spot" of most lenses? Is that true that the clearest pictures come out of that range?

So in what situation do you take your f stop all the way up to and around 22? Also is increasing the F stop number called "stopping down" ?

Thanks!

[mike_d]

f/8-11 is often the sharpest aperture but it won't have as wide a depth of field as smaller apertures. f/22 would be useful when you want as much in focus as possible. This can be useful in macro photography when the DOF is already very narrow.

[OdiN1701]

Generally never unless absolutely necessary.

You run into diffraction limitations and will actually end up with a LESS in focus image at a higher aperture than around f/8 f/11 or so on most DSLR's.

Look up info on hyperfocal distance - that should help you out.

[5Dmaniac]

This is an ongoing topic of confusion - the sweet spot of a lens vs. real life use of such. When you shoot landscapes, the hyperfocal distance (read up on this, if you don't know what this is) should dictate what f-stop you need. f22 is rarely used (at least with wide to moderate tele lenses), but I do use f16 quite a bit if I need the foreground and the background to be in sharp focus. Granted a singular point would be sharper with a larger aperture, but that does not help me if I need lots of Depth of field.

[argyle]

I am new to photography so I am still trying to learn the ropes. From what I gather, having a low f/stop of say, 2.8 is beneficial because it lets you shoot in low light situations with a higher shutter speed, and it also increases your depth of field.

I initially thought that when shooting landscapes, it was best to use f/22 because it got the most stuff in focus, but then I heard that f/11 is the "sweet spot" of most lenses? Is that true that the clearest pictures come out of that range?

So in what situation do you take your f stop all the way up to and around 22? Also is increasing the F stop number called "stopping down" ?

Thanks!

Just the opposite...the smaller aperture (larger f/ number) will increase your depth of field.

There's a lot of talk about diffraction, but I don't pay it much heed. If I need the shot and f/22 is called for, I'll shoot at f/22. For example, if I'm shooting a landscape with an ultrawide lens and I'm close to the minimum focusing distance with my foreground element, f/22 will usually be the required f-stop according to my hyperfocal table for that particular lens.

Yes...as you increase the f-stop number, you are doing what's known as "stopping down" the lens.

[nicksan]

I use f22 without hesitation, if I either want to increase the DOF or use slow shutter speed.
Diffraction is overrated...

http://nicksan.zenfolio.com/img/v3/p492855970-4.jpg

[DStanic]

Going higher then f/11 or so may also show any dust you may have on your sensor. :-P At least on my old 30D anyways, it doesn't have the auto dust shaker on the sensor..

[OdiN1701]

I use f22 without hesitation, if I either want to increase the DOF or use slow shutter speed.
Diffraction is overrated...



The shot you posted - there is not an issue with f/22 in that situation as the elements do not require any sort of critical focusing - the ocean water is blurred intentionally, and the clouds are not something that are exploding with detail that needs to remain sharp - so it's a non-issue in that shot.

[argyle]

Well then...here's one with plenty of foreground elements and plenty of detail, shot at f/22 with a 17-40L on a 5D2. Based on my composition, my hyperfocal table called for f/22. I hate to keep posting this pic, but it gets the point across that one shouldn't always get overly concerned about diffraction effects:

http://www.northlakephotography.com/photos/686025928_av9Ne-XL.jpg

[OdiN1701]

And I can see loss of sharp detail beginning to show in your background. Again this one works mostly okay because the background is relatively close.

[argyle]

This has obviously been resized and converted to jpeg. If you expect to see every edge of every bit of foliage in the background, I'd say that you're expecting too much and are being totally unrealistic. DOF doesn't mean that everything in it will be pin sharp, but rather that everything will be in the range of "acceptable sharpness". IMO, diffraction effects are overly exaggerated. Of course, it does depend on several factors such as gear, lens capabilities, sensor size, etc. On long distance landscape shots, what some think of as diffraction is usually nothing more than atmospheric effects (haze, heat, pollution, etc). My theory is, if you need the shot, take it and don't get overly concerned about diffraction. Better to take the shot and deal with any issues in post.

[nicksan]

And I can see loss of sharp detail beginning to show in your background. Again this one works mostly okay because the background is relatively close.

Why don't you show us example where diffraction destroys the photo so much to render it useless then?

[nicksan]

Here are a few shots I took while messing around with my lighting system...

f18
http://nicksan.zenfolio.com/img/v2/p827405614-4.jpg

f20
http://nicksan.zenfolio.com/img/v0/p421660453-4.jpg

f18
http://nicksan.zenfolio.com/img/v1/p178990131-4.jpg

f22
http://nicksan.zenfolio.com/img/v0/p856882514-4.jpg

f20
http://nicksan.zenfolio.com/img/v3/p114097684-5.jpg

I don't see a problem here...

[5Dmaniac]

I totally agree that diffraction is much less of an issue than many people make it out to be. I like my pictures to be sharp - no doubt about that - but overall DOF is often way more important than razor sharp focus on one particular subject.

[fly my pretties]

I generally only go higher than f12 if I'm shooting studio flash and the scene is already too bright to control with shutter speed

[OdiN1701]

nicksan - all of those have the subject close, so not really good examples.

Also - IIRC, a full size sensor like in the 5DII isn't as succeptable.

[RDKirk]

The shot you posted - there is not an issue with f/22 in that situation as the elements do not require any sort of critical focusing - the ocean water is blurred intentionally, and the clouds are not something that are exploding with detail that needs to remain sharp - so it's a non-issue in that shot.

I think that's rather the point.

One of the problems I see in these digital photography forums is that because so much about digital photography is quantifiable by numbers, newbies get the idea that it's all about numbers. All they have to do is get all the numbers right and their pictures will be good.

So they constantly hunt for the numbers to have--or the numbers to stay away from. "Will f/8 make my pictures better? Will f/22 make my pictures worse?"

Depending on the intent of the photographer, any given number can be good or bad. It's knowing what the numbers do, when to use them and what to use them for.

[MT Stringer]

I seem to remember the days of old when the lenses had the depth of field markings on them. A wide angle lens, when set at f/16 or thereabouts would have depth of field from about 3 feet out to infinity.

[lbridges]

You run into diffraction limitations and will actually end up with a LESS in focus image at a higher aperture than around f/8 f/11 or so on most DSLR's.

Not true. Diffraction limitation in this context has nothing to do with focus.

Actually, all else equal, being diffraction limited is a good thing. Yes too much might be wasted, but it's still better than not being diffraction limited.

To the OP - argyle's advice was spot on (IMO). Current knowledge/practice prevents the "perfect lens" from being created. The small f/stops (large number) tend to be on one end of the compromise envelope - they leverage increased depth of field in the trade space toward improved (perceived) image sharpness.

Bottom line - if you need it, shoot it, its still better than not getting the image.

[nicksan]

nicksan - all of those have the subject close, so not really good examples.

Also - IIRC, a full size sensor like in the 5DII isn't as succeptable.

...yet not one example where diffraction would be a big issue in the final product. (Not peepiing at 100%)

Anyways, this is pointless. There's really nothing to prove here. I stop my lenses down as I see fit. I don't worry about diffraction. Instead I worry about getting the shot.

End of story.

[OdiN1701]

I probably should have been more clear in my statement, you are right.

It really does depend on the subject and it is mostly only going to affect landscapes with a lot of depth.

[rdenney]

Diffraction is a fact of life. The smaller the aperture, the greater the diffraction. Diffraction can indeed limit the size of a print, and the smaller the image frame the strong the limitation for a whole variety of reasons.

But the smaller the aperture, the less pronounced the effect of lens faults.

People talk about those two influences all the live-long day, but it's just a waste of breath.

Use a wide aperture when you want a blurry background, and a small aperture when you want a sharp background. Those are the aesthetic reasons for selecting one aperture over another, and they affect the look of a photograph more than any other single decision we might make. Notice that this sweeps in the depth-of-field discussion, but without divorcing it from the look one might want with a wide aperture. We might want narrow depth of field as much as wide depth of field for any given photo.

But most of the time we pick a wide aperture because we need a faster shutter speed, because we need to stop action or because we don't know what that threaded hole in the bottom of the camera is for.

So, priorities:

1. Achieve your artistic intent, which in some cases may need a wide aperture, and in others a small aperture. It doesn't matter if the lens is at the sweet spot if you throw the picture away because it looks wrong.

2. Vary from the choice of #1 only as absolutely necessary to make a shot possible. We might be forced to use a wider aperture to freeze the action. (Freezing the camera is not an argument--use a freaking tripod.) We might in some cases have to narrow the aperture a bit because it's too bright. Shooting at f/1.4 in bright sun will reveal in a hurry why cameras need an ISO50 and maybe even ISO25.

3. Get a tilt-shift lens and use the tilts to manage what's in focus while still using the aperture that provides the desired look.

4. If you are taking a picture of a test chart, find the aperture that achieves the joint minimum of lens faults and diffraction. If you work at it hard enough, you'll have a sharp image of a test chart. Big deal.

Think of it this way: Get the priorities right and the picture will look good even when shown on a computer screen. Diffraction and lens faults are not visible except in over-enlarged samples, so the pictures posted in this thread to prove points, while pretty, wouldn't show ruinous diffraction or lens faults even if they are there. Choosing the wrong aperture for one's aesthetic purpose results in an image that looks bad at any enlargement. A little diffraction or a touch of spherical aberration can at worst limit the potential print size a little.

Rick "thinking we focus on the unimportant, so to speak" Denney

[binlerne]

Rick, good to see you posting again, I missed reading your posts as they are full of years of wisdom.

[alphonsis]

great information in here. Thanks to all!

[breal101]

Great posts from RDKirk #17 and Rick "hits the nail on the head... again" Denney #22. Being a man of few words I would have said if you need it use it. They said it so much better, thanks guys.