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I am somewhat confused. In photo school, we were always told to shoot at f64 for everything when using 4x5, because "depth of field was small with this type of camera". Well, I did, and everything came out fine. Now that I educate myself on this website, and see how everyone uses all the apertures, I'm confused. If any one has any feedback, its appreciated.
Well, I just got in trouble on another forum for using f/5.6. But I never went to school, and I only have to report to relatives (though I usually use f/16 on them). I mostly went 4x5 so I could separate out stuff I didn't want. I can obliterate an entire mountain range with f/11 for an outdoor portrait.
I'd play with it, mind you that's what I do.
Dean
I use DoF as a distinct element in my Fine Art photographs when it is called for. For instance when I want to isolate the subject from the background clutter or when I isolate it and don't want to just darken the background to do it. The main reason I use LF is because of the movements it affords me. I use the movements to keep DoF within manageable limits. I balance the need for large DoF and shutter speed. I like to expose film at optimum shutter apertures and shutter speeds. Why stop down to f64 when with movements I can stop down to f22 and use a faster shutter speed? The longer you leave that shutter open the more you chance flare and camera shake. Diffraction becomes an issue at those small apertures too. When someone tells you to do this or that make sure you insist they tell you why and then question whether it is right. There is too much misinformation out there about all manner of things. Question all of it. And test the premises. james
Why would anyone always shoot at f64 and face a risk of diffusion while in some situations Mr. Scheimpflug allows a perfect foreground- to-background-DOF at f16 to f22 and thus in the optimum optical range of the lens?
DOF is determined by several factors. 1.Focal length of lens, 2.Subject to lens distance and 3. aperture. If great depth of field is what you are after, all of these factors should be considered, plus, in the case of a view camera with movements, the use of the Scheimpflug rule. Every attempt should be made to achieve just the amount of DOF needed with the largest aperture with which you can accomplish that condition in order to avoid diffraction artifacts. As a rule of thumb, apertures smaller than f32 should be avoided in 4x5 work, f45 in 5x7 and f64 in 8x10. Does this mean that you can't use f45 in 4x5 or f64 in 5x7? No, not at all. Sometimes it is necessary to use one of the smaller stops in order to achieve the DOF you need. Maybe the lens is just too long, or the subject distance range just too great. It's not a rule, just a guideline, but one, if followed, will yield sharper results.
As the format increases, depth of field decreases but diffraction also decreases at any given f-stop. F64 with an 8x10 is equivalent to f8 with 35mm, so f64 is a moderate aperture for 8x10 and does not particularly need to be avoided. This is where the f64 group gets its name, but using 8x10 cameras with a moderate f-stop setting.
F64 is too small an aperture to recommend for most 4x5 work. Maybe your school was taking the f64 principle common for 8x10 and applying it to 4x5. F32 is the equivalent aperture for 4x5 (similar to f 8 for 35mm. I like to stay within the rage of f16-f45 for 4x5 work and f32- f90 for 8x10.
You were taught that because your instructor(s) didn't know any better. In three years of assisting with one of the top commercial photographers in the USA at the time and in sixteen years of shooting on my own I rarely go to f/32 much les s f/45. My experience is with shooting architectural and studio set ups. You have to learn how to use the movements of the camera and you have to understand the principles involved but that, in my opinion, is the way it should be done. going to f/45 or smaller f-stops with 4x5 starts to induce diffraction eff ects which affect sharpness.
I think that you should listen to what you ground glass tells you and ignore everything else that you've heard and read. I do landscape photography, and perhaps I can't compose to save my life, but there are many occassions in which I need to use f45-f64 to keep everything sharp. Tilt will save you only sometimes. If objects in the foreground or mid-scene have a significant height within your composition, tilt will not allow you to bring everything into focus. Finally, there are times when I'm in a hurry because of failing light, and then I just dial in f45 and go for it. You do what you have to do to make the image.
One of the great things about LF is the large view that you have before you click the shutter. It may be darker than desirable at times, but it is your only real guide.
Best wishes, Bruce
Bruce, keep in mind, the gg only shows what is in focus if you contact print at the apt. you are viewing at. Once enlargements come into play the circle of confusion becomes so large at higher f stops it limits your ability to enlarge... but all this aside, diffraction is still the limiting factor here.. assuming you are using a lens of high resolving power and Velvia film which under normal outdoor landscape conditions can resolve about 90 lpmm. Using the diffraction formula of 1500/fstop you will start diffraction with Velvia at f22, but need not really worry about it till f32, which should be the max. on 4x5. but from the chart below you can figure out yourself about how far you will allow yourself to stop down.. just divide the lpmm under the film by your enlargement factor and if the answer is 5 lpmm or greater, your perfectly safe. If it the answer is less than 5 lpmm, you can still be safe assuming you compensate for the lesser resolution by viewing the print from a further viewing distance. 5 lpmm is a good estimate of what the best human eyes can resolve.
f lpmm Velvia Provia 5.6 268 90 65 8 188 90 65 11 136 90 65 16 94 90 65 22 68 68 65 32 47 47 47 45 33 33 33 64 23 23 23
My guess is, this stop down theory was very appropiate in the days when films resolving powers were ver low. Hence difraction was not cutting into the process until much higher f stops. So at one time, f64 was probably a safe bet. But is the final product you are after, so just work into it backwards to determine what you are willing to accept. good luck...
Ooopps this chart looked right when I posted it, but I can see it went to pieces.... sorry.... Bill G