Thanks a lot everyone. At home, I did some research and came across a formula which yields an optimal aperture setting for macro photography. If I understand correctly, it is optimal in the sense of providing maximum depth of field without sacrificing resolution. The formula is A* = 1000C/(1+M) where C denotes the circle of confusion and M magnification. Hence, with M = 1.5 and C = 0.05 I obtain A* = 20. I could have used 16 or 22 and also would have gained a slight increase in depth of field. I will experiment more with this.
The limited depth of field is very attractive. For example, I can get one layer of leaves of a flower sharp while the rest vanishes out of focus. Or I can have one needle of the cactus sharp (on both counts) while the flowers remain out of focus and provide a nice complement to the sharp needle. I really like these effects.
A large cactus hardly bends with the wind. Therefore I was able to get a large number of sharp pictures. A sturdy tripod and mirror lock up are still necessary of course. For the Pentax I need these anyway.
I am amazed about the M-Componon which is optimized for M>1. The corner sharpness under the magnifier is simply stunning. The out of focus area is very smooth. What a great little lens. Watch out for it, I got mine brand new for less than 60 Euro.
I would love to show pictures but I don't have a scanner. I watch my slides projected on a screen.
Last edited by Joachim_I; 11-16-2009 at 06:07 PM. Click to view previous post history.