GG Loupe conversion from 35mm standard lens?greenspun.com : LUSENET : Large format photography : One Thread
I'm new to this forum, but scanning the loupe messages, I haven't seen this topic:
For contact prints, etc. I happily use an old 50mm lens (reversed) from my 35mm camera equipment. Many I know do the same. I've just started LF (Tachihara field camera) photography and haven't yet purchased a loupe for focussing (I've actually managed pretty well without one actually -- good prescription on my eyeglasses, I guess). However, I'm scared to bring this lens under the hood for fear of scratching up the ground glass with the aperture spring thingy on the lens and so forth. Also, not having a preset focus distance is much more awkward with ground glass than on a (light) table.
So the question is: does anyone have experience/warnings/tips for building a tube to attach to a lens to convert it into a loupe with a collar? The lens is a Zuiko (Olympus) f1.8, so it's pretty compact (about 3/2 the width of many loupes). Since I typically carry a 35 mm camera anyway, it would be nice if this collar was reliably reattachable for 35mm work.
Thanks in advance! Eric Pederson
-- Eric Pederson (firstname.lastname@example.org), January 10, 2001
Try drilling a hole through a rear lens cap make sure that there is enough lip to give support but not so much to obstruct the view.
-- john (email@example.com), January 10, 2001.
A great idea, except that the only rear lens caps I've seen for OM mount are fairly short. This means that the magnification is maybe 2x. But now that I think of it, there may be a rear cap for some of Olympus' bellows-only macro lenses with protruding rear elements which would be long enough to give greater magnification....
-- Eric Pederson (firstname.lastname@example.org), January 10, 2001.
As luck would have it, a No. 3 extension tube works perfectly on my Minolta MC 50mm/f1.4 lens. Better still, the bottom edge is nicely machined and thus smooth enough that I don't worry about scratching the ground-glass with it.
Perhaps you can find something similar for your Olympus lens?
-- Jeffrey Goggin (email@example.com), January 10, 2001.
Eric: I use a cheapie 50mm enlarging lens in a short piece of PC pipe. I measured the distance from the lens to ground glass when it is in focus, and cut a piece of PC pipe a little longer, then trimmed it to fit. Works great.
-- Doug Paramore (firstname.lastname@example.org), January 10, 2001.
Thanks Doug, that suggestion for use of a cheapie enlarging lens was one of the best I've found here in months. After reading Doug's tip a couple days ago, I took an old 75mm Vivitar I found at a show a few years ago,and epoxied it into a 2 1/2" length of black ABS. This was never much of an enlarging lens (I hated the lack of f/stop detents), but it's now part of the nicest focusing loupe I've ever used.
-- Lyle Aldridge (email@example.com), January 14, 2001.