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Reinhold Schable
21-Feb-2011, 16:18
I just posted a bleep about a simple meniscus lens on the Post Your Portraits Forum, but this is a better forum for discussing such things, sooooo...

I just finished mounting a soft portrait meniscus lens for my 5x7 Deardorff.
I'm delighted with the results, it handles like an old 1800's barrel lens.
And the negative it produces is just like a classic 1800's portrait...

The lens is a simple meniscus lens of about 300 mm focal length and a 60 mm diameter, giving a maximum aperture of about f5.6.

This is more than a patch-up collection of paper tube and duct tape.
The barrel is machined from PVC tubing.
The lens is seated against a machined stop and is secured with a machined PVC retaining ring.
It's fixed onto a Masonite lensboard with stainless flat head screws from the backside.
The next iteration will have a PVC flange so it can be attached to a lensboard from the front with small screws, just like it was done in 1880.

A 1mm wide slot machined into the barrel accepts aperture stops cut from black 4-ply matboard.
The matboard stops fit the slot nicely so light leaks are not a problem... if I don't dawdle between pulling the darkslide and taking the picture.
At first, I draped a black sock over the stop to cut down potential like leakage.
I'm happy to report that black socks are not required in the subdued light of a typical studio.

For a shutter, I flip a piece of black matboard across the lens, (I don't use the traditional hat, this is the 21st century, after all...)

I develop by inspection so each shot results in a good negative regardless of the exposure time which is somewhat imprecise, to be sure.

The photo of Larry was shot on Arista EDU 100, developed by inspection in Pat Gainers PCT 1+45 for 6-3/4 minutes. Shot it at f8, about 1-1/2 stop smaller than wide open. It's a straight scan of the negative.

Any interest in something like this?

Reinhold

www.classicBWphoto.com

Brian C. Miller
21-Feb-2011, 16:23
Where did you get the lens elements for it?

jon.oman
21-Feb-2011, 21:27
I'd like to try this some time!

walter23
21-Feb-2011, 22:03
Surplus Shed is a good place to look for odd lenses. They have lots of positive meniscus and doublets, etc. You can usually get one for about $5 to $10 depending on size.

Steven Tribe
23-Feb-2011, 02:16
In my search for achromats, I didn't find anything suitable (diameter/efl) at Surplus Shed. I have had much better success with general E**y listings and incomplete petzval projection lenses. There is still a 62mm achromat out there in E**yland. No connection to him - other than I have bought a couple of these!