Using a single lens element

[David Aimone]

Just playing around with a couple of old theater projection lenses that I picked up for pennies. They are brass and disassemble with 4 elements in them. One of the elements covers 4x5 alone and looks pretty good, but I can't leave it in the barrel without another lens behind it.

So, do any of you with more experience have any quick and easy ideas for holding/mounting single glass lens elements to put on the front of my Chamonix 045n-2 in a Linhof-Tech type lensboard? Or any other ideas?

[Andrew]

just an idea: plumbers tape the glass element to the back of the lens board so you can stick a packard shutter to the front? Any residual sticky "should" clean off the lens when you come up with a longer term solution... like mounting the glass in an old shutter? btw it might help to know how big this piece of glass is

[David Aimone]

I do have a small packard that's just a tiny bit smaller than the lens element, which I'd say is in the neighborhood of 5cm in diameter. I could probably affiix it onto the front of it...

just an idea: plumbers tape the glass element to the back of the lens board so you can stick a packard shutter to the front? Any residual sticky "should" clean off the lens when you come up with a longer term solution... like mounting the glass in an old shutter? btw it might help to know how big this piece of glass is

[Andrew]

sounds like you've got your starting point to begin experimenting

[Lachlan 717]

Ring of Blu Tac?

[David Aimone]

Now that's a good thought...off to the store this weekend...

Ring of Blu Tac?

[David Aimone]

While we're at it, is there an easy way of guestimating the aperture of this single lens element, stuck to the front of the packard?

[Fotoguy20d]

If you know the focal length (distance from lens to ground glass at infinity should be close enough), and the diameter of the opening, you can easily calculate the aperture as length/diameter.

Dan

[David Aimone]

sounds like a good guestimate. I will try it all out this weekend and see what I get as a resulting photo!

If you know the focal length (distance from lens to ground glass at infinity should be close enough), and the diameter of the opening, you can easily calculate the aperture as length/diameter.

Dan

[Lachlan 717]

While we're at it, is there an easy way of guestimating the aperture of this single lens element, stuck to the front of the packard?

Take a meter reading from your ground glass with a known lens at a given f-stop, then put on the single lens and do the same.

Compare the difference in exposue and extrapolate the difference in stops.