Sharpness and DOF question.

[sandrael]

Dear patrons of the forum, I am sure it is quite a recurrent question but after reading too much theory I got a littlbe bit confused on this matter. In the book "Understanding Exposure" the author mentions that for landscape photos you should use f/22 in order to have sufficient DOF so that the whole landscape is in focus.

However now I have discovered that using f/22 will render photos not tack sharp because at that aperture you start to loose sharpness and the sharpest apertures are usually couple stops down from wide open.

So the questions is what aperture to use to render landscapes sharp and n focus then? What apertures do you usually use for taking photos of lets say building like churches or museums? And how exactly do you know what aperture do you need to render subject both sharp and in focus?

Thank you for all your help and answers!

 

[C4n0n.Fan]

Here is a calculator for you. Im no pro. but the most I'll ever use is f13 maybe more if I need to stop down on light.
I don't know why their telling you f22. you will always get chromatic aberrations, although higher end lenses handle it better than cheapies.

 

[o hey tyler]

Read up on hyperfocusing. That's exactly what you want for this situation.

 

[radiorickm]

Ok...this is not a personal attack....but this..... but the most I'll ever use is f13 .... is just plain silly.

You have different f-stops on you lens so that you can....USE...them.

I assure you that Bryan Petersen pretty much knows what he is talking about.

If you need to capture a scene with a very deep depth of field, of course you can use f22. Yes, you may give up a TINY bit of sharpness to get the depth of field, but that's ok; the photo is about the depth of field. This is one of those SUPER-CRTITICAL issues, that as a newby you probably don't need to worry about in 98% of your photos.

Now, if you are shooting the cover photo for Sports Illustrated annual Swim-suit issue, and you want to count every eyelash on your model, yeah, then set your lighting up so you are in that sweet spot on the lens.

Most things in photography are about an acceptable compromise. Give a little sharpness and get a greater depth of field. Give a little ISO speed to get a higher (acceptable) shutter speed.

Go out and enjoy shooting. Don't get so caught up in the "technical" stuff. If (and when) you get good enough to notice the difference in sharpness (and I do mean sharpness, not depth of field) between f5.6 and f11, then you can decide which to use.

 

[TruckerDave]

I never understand threads like this (not attacking the OP but this type of thread in general).....you have a camera and lens. If f22 doesn't work for you simply change it and try again. If this still doesn't work keep changing and reshooting until you get the effect you want. The time wasted asking the question could have been spent experimenting with the different settings on the camera to get the desired results.

 

[o hey tyler]

Ok...this is not a personal attack....but this..... but the most I'll ever use is f13 .... is just plain silly.

You have different f-stops on you lens so that you can....USE...them.

I assure you that Bryan Petersen pretty much knows what he is talking about.

If you need to capture a scene with a very deep depth of field, of course you can use f22. Yes, you may give up a TINY bit of sharpness to get the depth of field, but that's ok; the photo is about the depth of field. This is one of those SUPER-CRTITICAL issues, that as a newby you probably don't need to worry about in 98% of your photos.

Now, if you are shooting the cover photo for Sports Illustrated annual Swim-suit issue, and you want to count every eyelash on your model, yeah, then set your lighting up so you are in that sweet spot on the lens.

Most things in photography are about an acceptable compromise. Give a little sharpness and get a greater depth of field. Give a little ISO speed to get a higher (acceptable) shutter speed.

Go out and enjoy shooting. Don't get so caught up in the "technical" stuff. If (and when) you get good enough to notice the difference in sharpness (and I do mean sharpness, not depth of field) between f5.6 and f11, then you can decide which to use.

More often than not, lenses won't need to be stopped down to f/22 to provide the adequate depth of field. So at a certain point you're harming image quality for no reason.

 

[Derrel]

Many camera have a depth of field preview button. You can use that to place the focus by doing what is called "stopped-down focusing", but that can be pretty tricky without a lot of experience. A second approach is to use a lens that has a depth of field scale engraved or painted on its barrel--but that scale only works when the lens is used on a camera with the "native" film or sensor size, such as a DX-lens on a DX body Nikon, or a FX body in DX mode, or an EF-S lens on a Canon crop-body, or a full-frame Canon lens on a full-frame Canon d-slr. Using the scale, one can literally see different f/stops, and the focused distance, and then the near-limit and far-limits of the depth of field, for the various f/stops listed on the DOF scale.

ANother,third way, is to take some shots, and use the LCD to review things, to see how the specific focus and aperture in use are working out, but this is very slow, and might not work all that great in brighter light.

The fourth method is taking multiple shots from a tripod-mounted camera, and moving the focus, and then using software to do what is called "focus stacking". FOcus stacking used to be a PIOTA, but newer software makes it much faster and easier.

As far as hyperfocal distance focusing (which o hey tyler referred to above as hyperfocusing): in theory, it works pretty well. However, with today's high-resolution cameras and larger prints or crops seen on big monitors: it often does NOT really work out all that well. Yes, hyperfocal distance focusing does sorta' work, but many times, I find it distracting to see the slightly sharper distant objects rendered more-clearly than closer,larger, more foreground objects. Now, in SMALL prints, like 4x6 prints, hyperfocal distance focusing can look "okay" to even very good. But the advice of many landscapers is to focus on the most-important object, and render that the most-sharp.Digital shots are pretty much "free", so you can try a number of different approaches. One I like is to subtly vary the focusing a little bit...focus in the front, then move the focus backwards, bit by bit. At smaller f/stops, like f/8 to f/11, there's usually plenty of DOF and the resolution of the lens is usually not all "that badly" hurt by diffraction...modern cameras that have plenty of MP might resolve more detail at wider f/stops, like f/4 tgo f/5.6, but if there is too much that is out of focus, it's a wash, or a net loss, and you'd actually be better off stopping down to f/13 to f/22 to get deep,deep DOF, if that's what a shot really,really needs.

 

[bratkinson]

Most things in photography are about an acceptable compromise. Give a little sharpness and get a greater depth of field. Give a little ISO speed to get a higher (acceptable) shutter speed.

You couldn't have put it better, radiorickm...'acceptable compromise'. I consider it the exposure triangle 'battle', and in the end, come to an 'acceptable compromise' to get the shot the way I want it.

 

[batmura]

I too would like to know why Bryan recommends f/22 if it affects sharpness.

 

[rambler]

Derrel, a satisfactory "stacking for focus" software is http://www.heliconsoft.com

 

[jwbryson1]

I too would like to know why Bryan recommends f/22 if it affects sharpness.

Bryan also uses a tripod in a large majority of his photos when he does not necessarily need to because of the VR in his lenses and fast shutter speeds. However, using a tripod (or stopping down to f/22 when f/16 may have been sufficient) could yield just that extra tiny additional bit of sharpness that you lose in other situations.

 

[jwbryson1]

Read up on hyperfocusing. That's exactly what you want for this situation.

^^^ This.

 

[EIngerson]

I too would like to know why Bryan recommends f/22 if it affects sharpness.

When he says "acceptable sharpness" he implies that there might be some loss, but it's acceptable. The photo will still come out great and you won't see the softness until you start pixel peeping. As with anyones style it's "a way" of accomplishing the task. Never rule out anyones advice. the more tools you have the more versatile you are.

 

[Overread]

Each photographer has their own way of working and when they teach others they often impart their method to the students. In truth there is no such thing as "settings for landscapes" or "settings for macro" etc... Because those are not things in photography, they are simply wide categories. Beginner books often give generalist settings to start with so that those learning can see a result - copy the settings and get a generally similar result themselves and thus feel empowered and build on that success. Once you've got that far you have to then branch out and play

The core is to learn the exposure triangle - learn how each of the 3 variables will affect your final photo - learn how to focus and about things like focus stacking and hyper focal focusing and do some reading on composition (don't just read about rule of 3rds - branch out and learn a lot more like colours, shapes, lines, brightness, golden spiral etc...).

Once you've go the core skills and methods you can do the most fun and important thing - experiment.

Play and mess around (I assure you film photographers did this all the time too) and see what you get. Try a macro photo with f13 - then try one with f8 and then f5.6. See how those different variables affect the final photo and then be empowered to make a choice between them as to what will suit the scene and the shot you want to take - this is far more empowering than simply shooting the "default suggested" settings by other photographers. Sure in time you might find that you get your own default settings and that you'll shoot them fairly often - they might not, however, be the same defaults that others have.

 

[EIngerson]

^^^^ Well said.