Hello guys and girls,
the other day i was shooting what i thought were beautiful portraits at night with an SMC-M 50mm f/1.7 wide open and a Pentax K-x, and when i got home i found a bunch of out-of-focus pictures. I was really frustrated to having missed those shots, so i got inspired by a video about adapting a film-camera split-prism focusing screen, and next day i got my hands on the doing.
This is the video
, and the rest of the post is about the experience of doing it.
I got started dissasembling a Canon T60, taking out the pentaprism to acces the focusing screen (this model has not interchangeable focusing screens, so it must be accesed from the inside)
Then i got the focusing screen out
After removing the screen, i removed the K-x screen to measure its size, and draw it in paper to find its center so i could match it to the location of the prism-ring containing the split-prism in the CanonT60 screen. I secured it with scotch-tape and placed slide-glasses on both sides for protection.
These were the tools: Tweezers, microscopy slideglasses, Cutter, and those black things which look like metal-butterflies that are used to holding glass.
Next thing was to place the focusing screen in the camera, on top of the mirror, without the shims. After some manipulation, it got into place and i locked the slot in the viewfinder, and the focusing screen is doing its marvellous work with fast manual lenses, and it doesnt affect autofocus nor metering at all. It works quite great on tele lenses about 135mm, but regarding wide angles the split-prism shows an image a bit unaligned when in focus. Still i bare with it with the aid of focus-confirm though.
Well, that was all, i just wanted to share with the forum that this is possible in the Pentax K-x, and to hear if anyone else has tried adapting an old screen to fit a DSLR.
Regards from Uruguay