Periscope for off angle viewing ground glass LF

jamaeolus · Expire: 2015-08-20

So I have just begun dabbling in LF and found the angles I like to take photos somewhat troublesome to use the loupe to focus the image on the ground glass. Being old and having a bad back aggravating the situation. MF traditionally used a mirror to the ground glass. Looking through my random bits I noticed a couple angle viewfinders for 35mm SLR. One, a yashica had a female form to slide in place of the removable flash mount. The other a Canon had a mount to slide into the more recent permanent attached flash mount. Kismet, i thinks. Nope not so fast. It doesn't slide on. Well after some close inspection it seemed the post on the canon below the metal plate that would slide was impinging on the lip of the yashica. A few minutes with a small file and it slides on and the optical parts ALMOST line up. I get an image right off though it isn't quite centered. Another inspection and some metal flanges are preventing the plate on the canon from sliding quite far enough. Bend them over with a pair of needle nose and it aligns pretty close to perfect. Now can I get it to the right distance from the ground glass to focus? Holding it up I can get an estimate. Using 2 cheap m42 extension tubes, 14mm. The rubber eye cup on the canon mates with the inside of the tube with enough friction to stay in place. A couple adjustments AND IT WORKS!

Doc Sharptail · Joined: 23 Nov 2020 Posts: 994 Location: Winnipeg Canada

Interesting, and congrats on your success!

Any idea of magnification- if at all? I haven't viewed a lot of R/A eyepieces, but the few I've seen were pretty tiny and dark.

-D.S.

jamaeolus · Expire: 2015-08-20

I'm too lazy to calculate it but I would guess maybe 4x. Definitely enough to be useful.