Adapting a Nineteenth Century Lens for Modern DSLR Use

Submitted by maz on Thu, 12/23/2010 - 12:57

On a whim I went to Real Camera and asked if they had any old, vintage, and ideally "soft" lenses for sale. Was I about to be in for a treat!

Ross London Lens

Ross made lenses from about 1830 till they were bought in 1975. Without further information, a little guess-work suggests this might date from the late 1800s: it lacks a focussing mechanism, and has no iris for aperture. Still, it has a focal length of around 30mm and based on that and the area of the lens you can calculate it is equivalent to around f/1.4 fully open. Initially I thought adapting this lens would be relatively easy, but its flange focal distance was far too short for a modern DSLR. This isn't even a case of trying to put an FD-mount onto an EF-body where infinity focus isn't possible: the only thing this lens would be useful for would be supermacro photography!

[caption align="aligncenter" width="512" caption="Weave of Camera Bag"]

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Undeterred, I stripped the lens and removed one of its three elements, and after a little experimentation with lens placement, managed to get something which would deliver reasonable focus onto an EOS camera. To mount it I cut a hole in a bodycap and used a Dremel-like tool to sand it to be a slightly tight fit for the thread on the back of the lens like this:

[caption align="aligncenter" width="512" caption="Lens Mounted in Bodycap"]

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I then adjusted the focus by screwing it in and out till I found where I wanted it to be — about 1.5m — and sealed the lens with a hot glue gun. Of course this means I can't refocus the lens, but for £5 I don't think I'm worried about this being a one-trick pony.

[caption align="aligncenter" width="512" caption="Sealing the Lens"]