Does anyone have any information regarding this lens? Its a triple convertible (13 1/2", 20 1/2" and 28") from around the turn of the century (not the last one, the one before that). I was wondering if it was related to the Turner Reichs. More to the point, I was wondering about possible shutters I could adapt it into. Its in some gamey 'Unicum' kind of shutter right now. I guess Packards might be an option but I was hoping someone might be able to tell me keep my eyes skinned for a Betax No 4 or something. Cheers, DJ.

-- N Dhananjay (ndhanu@umich.edu), April 08, 2001

Answers

Check out the following link for a brief history on Gundlach and other Rochester lens manufacturers:

http://www.cif.rochester.edu/~ardavis/history/kingslake.html

It looks like Reich was an optician and Turner a machinist. Ernst Gundlach has his own history, including a stint with B&L.

On the lens, I have one reference which lists a Gundlach-Manhattan Rapid Rectigraphic Convertible with 14, 20 and 28 inch cells. The reference indicates that all three cells combined yield a 14" focal length and a maximum aperture of f8. The rear cell (alone) provides 20" at f16, and the front cell (alone) gives you 28" at f22. The reference also indicates that the lens is composed of 10 elements in two groups (is that possible with a triple convertible?). As far as coverage, all three cells combined are listed as covering 8x10. The rear cell covers 14x17 and the front cell 16x20.

I assume the lens is uncoated and that the quality of the lens degrades (like most convertibles) when cells are used alone to produce increased focal lengths. I hope this information helps.

...........................

-- Dave Willison (dwillisart@aol.com), April 09, 2001.

"The reference also indicates that the lens is composed of 10 elements in two groups (is that possible with a triple convertible?)."

Indeed it is not only possible but quite likely for a Gundlach convertible. The front cell is one cemented group of five cells, and the rear likewise.

-- Sean yates (yatescats@yahoo.com), April 09, 2001.

I own one of these. Mine is labeled "Gundlach-Manhattan Optical Company Rochester NY Rapid Rectigraphic 8x10 Front Lens 28 In. Pat Dec 9-1890". Contrary to what Sean stated, this one is definitely not a 5 element per group design. That may be true for the Rapid Rectilinear (though I recall that being fewer as well), but this one appears to be in two element (three max) groupings. Mine is also 13 1/2 - 20 1/2 - 28 but is mounted in a Gundlach two- cylinder "compound" style shutter. It is crap, but it has a Feb 8 1900 patent date on it and works well at T, B and 100. I've considered having it adapted to my Copal #3, but...

-- Chad Jarvis (cjarvis@nas.edu), April 10, 2001.

Here's what Rudy has to say

"In 1890 Ernst Gundlach, then living in ROchester, New York, patented a variant of the Rapid Rectalinear in which he used three cemented elements in each half instead of two. The numerical construction of this lens was not disclosed, but probably its performance did not differ significantly from that of the Rapid Rectalinear."

So where the source citing 5 cells in two elements got the info from is anyone's guess. Kingslake does have this to say though, which is kinda neat:

"If you compare the structure of the Zeiss Quadruple Protar Series VII with the structure of the Turner-Reich lens, (the commonly available convertible) it will be seen each consists of an old- achromat on the outside with a new-achromat doublet close to the stop. The difference between the two designs is that in the Zeiss lens the old-achromat is similar to half a Rapid Rectalinear. while in the Turner Reich lens the old-achromat resembles hald of Gundlach's Rapid Rectagraphic objective. As the performance of the of the Rectagraphic and the Rectalinear were basically the similar, we may expect to find the Turner-Reich lens would be no better than the Zeiss Series VII, which is indeed the case."

-- Sean yates (yatescats@yahoo.com), April 10, 2001.

I believe the 10 element reference (two groups, five elements each ) refers to the construction of the Turner-Reich, which came after the Rapid Rectigraphic. I have a couple rectigraphic cells, but have not gotten around to using/testing them yet. Someday... Tracy Storer

-- Tracy Storer (tstorer480@earthlink.net), April 22, 2002.