Today was a verrrrr big day for my photography kit. I had previously converted a couple of fast prime lenses for use with my Nikon (from Cannon FD mount) but they were pretty frustrating to use. The stock "brightscreen" focusing screen in my D70 is plenty bright, alright. And it has just about no depth of field perception. One can hardly tell with an f/2.8 screen what an f/1.8 lens is focusing on. This bums.
Yesteday I trashed a defunct Cannon AE-1 camera body for one reason: I gots to get me some manual focusing aids. The AE-1 comes to us from a time when men were men, lenses were fast, and focus was strictly manual. The focusing screen has both a split prism and a microprism collar. And it's bigger by quite a lot than the screen in a D70 (or D40/D60 etc.). Alex's blog let me know just how much bigger. The D70 screen is 1" x 0.8". The screen in this AE-1 was 36.7mm x 24.7mm. Alex's Blog brings the knowledge. Many, many thanks to Alex.
So I cut down the screen.
Click to enlarge the photo!
I scored the screen with a caliper to be sure the dimensions were proper, and cut it with a file which has a sharp corner. I covered the middle of the screen with scotch tape while I was working, to protect the fragile surfaces. It worked like a champ. I used polishing paper (read: super-duper fine sandpaper on plastic vs. paper backing) to finish the edges and that worked like a champ as well.
The final result:
It works. It did get a bit of foam smutz on it and most of that cleaned off with alcohol and some q-tips. The screen was from a Cannon so it was too thin with the edges trimmed off, so I had to use the shim from the camera AND some tape on the screen AND another shim. When the screen is too close to the prism, the camera has "back focus" . . . I added shims until it focused where it should.
That's on TOP of the fact that someone straight-up GAVE me a half-decent tele-macro zoom lens yesterday. That gets the score up to two zooms to cover me from 18 to 300mm, plus two fast primes. That's a full beginner's kit. That, plus now I can see where I'm focusing. Win.