Author Topic: What f-stop is best for microstock? (Read 5401 times)

Whiz · « **on:** November 05, 2007, 22:27 »

In the beginning, I didn't even know what an f-stop was so I used the default camera settings(sad, I know). I think it was 2.8 or so. Now that I understand what it is, I use an f-stop of around nine for most of my photos. I've read that a really high f-stop can make the image less sharp. What are your thoughts?

Gregor909 · « **Reply #1 on:** November 05, 2007, 22:38 »

Hehe that's a weird question!
It doesn't matter, as long if your photo is sharp and noiseless. And every image needs another DOF, depends on the subject!
What ISO setting is best for microstock would be a better question; so low as possible.

berryspun · « **Reply #2 on:** November 05, 2007, 22:55 »

Whiz, here is a link for a very good depth of field summary calculator for the f-stop / subject distance / focal length relationship:

http://www.dofmaster.com/dofjs.html

Is this helpful?

Whiz · « **Reply #3 on:** November 05, 2007, 23:04 »

Quote from: berryspun on November 05, 2007, 22:55

Whiz, here is a link for a very good depth of field summary calculator for the f-stop / subject distance / focal length relationship:

http://www.dofmaster.com/dofjs.html

Is this helpful?

Yes. The author of that webpage used a few too many Google ads, though.

wysiwyg_foto · « **Reply #4 on:** November 05, 2007, 23:57 »

You could always use the rule of "sunny 16"

http://www.dgrin.com/showthread.php?t=30235

...or the rule of "f/8 and be there"

(f/8 and a shutter speed faster than 1/500 for hand held shots).

In the end though, the best f-stop is the right f-stop for the situation.

hatman12 · « **Reply #5 on:** November 06, 2007, 02:14 »

Yes, a very high F stop intoduces a phenomenon called diffraction which causes deterioration of sharpness.

My Nikkor 35mm F2 for instance starts to deteriorate at about F14 and I can see an obvious difference in sharpness if I take the same shot at F11 and F16. Consequently I never use this lens at more than F13. Between F2.8 and F13 it's wonderful.

Macro lenses tend to be optimised for deep DOF so my Nikkor 60mm Micro takes perfectly sharp pictures all the way to F32 and is best between F11 and F32.

Bateleur · « **Reply #6 on:** November 06, 2007, 03:06 »

In general the mid-range, f8 to f16, is the best setting for most lenses. And lens tests bear this out. Look at the curve of the graph.

I try to find the 'sweet spot' for a particular lens and, when using it, shoot at that aperture as much as possible.

My advice would be to stay away from the maximum and minimum apertures of a lens (though it isn't always practical ... if you want a large DOF, for example, or if the light is very low).

pigscanfly · « **Reply #7 on:** November 06, 2007, 08:52 »

Check the MTF graph of the lens and try to shoot within the sweet spot for your lens.

A f/2.8 lens does not mean that it will be best at f/2.8. Sweet spots are usually between f/5.6 to f/11.

snem · « **Reply #8 on:** November 06, 2007, 11:35 »

And fot MTF graphes I suggest this site http://www.slrgear.com/reviews/index.php
Regards

Gregor909 · « **Reply #9 on:** November 06, 2007, 12:05 »

Very valid points.
But to come back to the initial question; I don't think there is a wrong F-stop for microstock.
I've had F32 images accepted on IS,SS,StockXpert and DT, made with my cheap ass kit-lens, on-camera sharpening off, and no additional post processive sharpening applied.