Deardorff Extra Rapid Portrait lens

[Chauncey Walden]

Formatoff, those sound like Uniform Standard (US) aperture markings and would be equivalent to f/4, 5.6, 8, 11, and 16.

[formatoff]

Thank you so much for the good info for me, CCHarrison & Chauncey!
I'm gonna test it with my shutter.

[Amedeus]

I realize this is an older tread but I just want to add my 2 cents to this for future reference ...


http://amedeusphoto.zenfolio.com/blo...ortrait-4-lens

[AtlantaTerry]

I realize this is an older tread but I just want to add my 2 cents to this for future reference ...

I don't get it. What difference does it make if this thread is a day or a year or ten years old?

[Jim Galli]

I don't get it. What difference does it make if this thread is a day or a year or ten years old?

Rudi has given us new and very interesting information including pictures which is great! Thanks. Makes no difference if info is pertinent and people are interested. OTOH some threads are better left . . silent

[Amedeus]

Thanks Jim,

FWIW, I updated my blog post on the Deardorff Extra Rapid Portrait lens with a few more images I found on-line.

I also came across a saved ebay listing from July 15, 2010 showing a Deardorff Extra Rapid Portrait #4 lens that didn't have the Gundlach 1891 Patent helicoid (nor mention of the patent date) but instead had provision for the rear cells to be separated for extra "diffusion". Four (4) positions marked, not unlike the Dallmeyers ...

This is the lens type that's in the 1903 Deardorff catalog. The serial on the #4 is 1010 while the serial on the lens depicted in the catalog is 1013. Very close. The serial number on my #4 1891 patent Deardorff is 1054. For completeness, the unit I have also has the provision to separate the two rear cells ...

Gimmick, but nevertheless, it's there ...

http://amedeusphoto.zenfolio.com/blo...ortrait-4-lens

The new info can be found all the way at the bottom.

Cheers !

Rudi A.

Rudi has given us new and very interesting information including pictures which is great! Thanks. Makes no difference if info is pertinent and people are interested. OTOH some threads are better left . . silent

[Jim Galli]

Interesting that Gundlach envisioned his design with no air space at either end.

[Amedeus]

I don't believe Gundlach was targeting Petzval designs but rather more modern designs. Since it appears Gundlach patented his changing-distance-between-lensgroups prior to Deardorff, Deardorff claiming same for Petzval configuration would have been obvious for anyone skilled in the art ...

Interesting that Gundlach envisioned his design with no air space at either end.