Any Info on "The Adjustable" - C.C. Allen Optician - Old Brass Lens

[DanK]

Picked up this lens, thinking it was a simple barrel petzval....I haven't seen, or read of this type lens....hoping someone might help....

It's stamped "The Adjustable" Made by C.C. Allen Optician Chicago Pat Apr 1 1902

This has a single element in front....and four elements in a group in the rear....PLUS....a moving inner single element....

When you turn the front hood it moves the center element on a spiral rail within the barrel....

First I've seen the grouping, with 6 total elements and movable interior....

Any Ideas?

I'll try and get a photo of it up this evening....

Thanks,
Dan

[Richard Rankin]

I think it is an early 'zoom lens as Allen had one patented, according to the lens VM. If so, should give a small amount of 'zoom' by moving a positive lens between 2 negatives or vice versa. It might not be usable by itself. It might be an accessory to add in front of another lens.

Just my guess, but I can't wait to see the photos...

Cheers,
Richard

[Richard Rankin]

BTW, the Lens VM seems to list the incorrect patent number for Allen. Here's what I found:

http://www.google.com/patents?id=vaF...201902&f=false

[DanK]

Photos of the lens in question....

Thanks, Dan

[DanK]

More Photos...

Thanks

[DanK]

Thank You Richard....

BTW, the Lens VM seems to list the incorrect patent number for Allen. Here's what I found:

http://www.google.com/patents?id=vaF...201902&f=false

[Amedeus]

I picked one of these up recently also ... later serial number 28xx ...

There's not much info on these ;-)