I got a bit fed up with the unusable focusing screen of my Pentax K10D, which made everything look sharp even if it wasn't. So I grabbed a defective Pentax ME-Super which has a nice ground glass screen with microprisms and a horizontal wedge (I don't like the diagonal ones). I did the following:
- Remove the ground glass screen from the ME-Super. For that I had to remove the whole top plate and prism assembly.
- Remove the ground glass screen from the K10D. This is easy through the mirror box.
- Wear a pair of latex gloves, and grind the sides of the new screen on a piece of fine sandpaper. It's impossible to keep the sides 100% straight but it can be done. Do this for all sides until the size of the new screen is the same as the old one.
- Clean the new screen with a can of compressed air (don't move it while blowing, as this will spray moisture on the screen!)
- Put the new screen in the ground glass screen frame of the K10D (notice that the grounded side of the ground glass must be in the UP position), and push it up until it clicks in place.
My first reaction: the screen is not as clean as I thought. But there's not more dust on it than on the original one, so I'm still happy
My first reaction when looking through the viewfinder, focusing a 50mm f/1.8 Carl Zeiss Jena Pancolar Zebra: WOW! I've waited for 7 years but I have now my favorite screen back... And focusing is a breeze now, even if I only use the matte part of the screen. No more unsharp pictures from now on unless I want them to.
The screens. The top screen is from the ME-super, already grinded, and the bottom one is the orginal one from the K10D. The tab is not really necessary, it only makes removing the screen easier.
The screen already installed. Who wouldn't love the sight of a really usable ground glass screen
I focused on the "H" here.
The first time with my K10D I got the focus immediately right: perfectly in the middle of the screw.