Today was the first time I tried the K10 with my new home made focusing screen. It was a great feeling to finally be able to see the sharpness pop into place as on the good old film days. Sure the screen is darker, but I am only planning to use it for lenses between 1.4 and 2.8, actually I hardly have anything slower anyway.
I have made old style screens by etching glass of the correct thickness. I have also tried the old method of grinding, but found the etched ones as good, and easier to make. I am going to experiment a bit more on the depth of the etchings, but after today I feel I already have a perfectly working solution. The only issue I am expecting is the metering. Since my screen will have a much more linear behaviour than the modern plastic F4 variants, I will expect to have to make some compensations. My screen is also darker, which should cause over exposures.
The surface is completely envenly etched (it took a couple of failures to be successful). You can see the surface of the screen, until suddenly the picture gets sharp.
Today I shot with the M100/2.8 using Av, and that of course worked perfectly. I was actually surprised I only had to compensate -0.5 to get correct exposure from the camera, I thought the focusing screen was darker than that.
Using M setting and a smaller aperture caused more problems with over exposure. I had to manually adjust the time -1.5 when using F5.6. A pity you can't use exposure compensation when using M. Since the 100/2.8 is extremely sharp already on 2.8 it was an easy decision to switch to Av instead.
The plan has been to put this screen in the K20, but after today I was tempted to try it in the K-7 as well. I think I will try to stick with the original plan though.
Picture below was taken using only manual focus, using Av on the K10 with M100/2.8. Focus is spot on. Will increase the challange by using a 1.4 lens next time :-)
Last edited by quarc; 09-02-2009 at 12:37 PM.