What you should know about diffraction!

[paulatukcamera]

Honest, I knew none of this! It came as a "bolt from the blue", proving how ignorant I really am about lenses!

I came across a thread in DPReview (in the Panasonic section) about the fact that you shouldn't stop right down to f8 (my minimum) to get increased depth of field because performance on a small sensor suffers through diffraction effects.

The following link has just been posted which explains in great detail and very clearly the "whys and wherefors"

www.cambridgeincolour.com/tutorials/diffraction-photography.htm

It is well worth reading - it certainly opened my eyes to the dangers of stopping down to the minimum on my FZ20. I now use f5.6 a lot more, though according to the calculator in this article, f4 should be my minimum!

I also find it difficult to conceive that at f4 I am getting the depth of field of f11 on my 35mm! Must try harder...........

Paul

[nikonbob]

Paul

Thanks for the link, I've bookmarked it. I have been vaguely aware of diffraction for awhile and have always tried not to stop a lens down all the way if possible. Both my digi cames have the small 4/3 sensors, I think, and I thought I saw huge DOF when shooting at F4 as compared to F8 with film. I did a little researvh and found out I wasn't just seeing things. You really have to rethink your aperature choices with the different sensor sizes and I am told that the same is true going to larger film sizes, only in reverse as far as DOF goes. Again you are changing the sensor size if you will. I think that the small sensor size is an advantage in that it will let you shoot in lower light levels at lower iso settings and still get decent DOF when compared to 35mm film. Add a stabilized lens and you can really expand your handheld shooting time.

Bob