[gabriel_bc]

Since I mainly shoot MF lenses (I only have the 18-55 AL II lens in AF) I have long wanted a split prism focusing screen for my K10D - but the funds just aren't there right now.

So, I decided to take the bull by the horns and MAKE one, darn it. I was surprised at how easy it was.

The basic strategy was to remove a split screen from a dead film SLR, and cut it to size on my bench grinder. The first attempt (using a dead Minolta XG-A) went ok, but I scratched the prism up something fierce on the tool rest of the grinder. Duh.

Try #2 was much better - this time the donor was a Nikon FG-20 (good use for Nikon gear!) - I stuck some self-adhesive felt to the tool rest, and held it freehand with cotton gloves as much as possible. The result - much better (although there are a few nicks here and there, as well as a few from when it was in the camera - I think someone tried to clean it once).

I angled the cuts to get a diagonal prism in the final screen - and it works GREAT. Tested the focus with a ruler at 45 degrees - spot on. Man, how did I ever focus MF lenses before? (well, the large number of OOF pics says I didn't, at least not very often!).

So, a nice split screen and the price was right!

[reeftool]

While I haven't attempted to make my own split screen, I did install a pair of prescription eyeglass lenses into a pair of drugstore sunglass frames once when I broke my glasses. By clamping some emery cloth to a flat work table, I ground down the edges to make a perfect fit and it went fairly quick. This would be much better (although slower) than using a grinder and you can get the fit almost perfect.

[asdf]

I angled the cuts to get a diagonal prism in the final screen - and it works GREAT. Tested the focus with a ruler at 45 degrees - spot on.

That's great! My ebay split prism was a bit off without the right shim.

[Transit]

The basic strategy was to remove a split screen from a dead film SLR, and cut it to size on my bench grinder.

I reached for the belt sander, never thought of the grinder