[largeformat] value on 11x14 lens

[Richard Knoppow]

----- Original Message ----- 
From: "LNPhoto" <LNPhoto at twmi.rr.com>
To: "f32 Large Format Photography Mail List" 
<largeformat at f32.net>
Sent: Thursday, June 16, 2005 3:26 PM
Subject: Re: [largeformat] value on 11x14 lens


>A bit more on the lens in question.
>
> This is a Gundlach Manhattan "Rapid Convertable"  It 
> doesn't say  Anastigmat, it doesn't say Rapid Rectiliniear 
> either, though I think it  is.  The glass seems to be a 
> pair of asymentrical cemented doublets,  nothing like the 
> massive Turner Reich lenses.
>
> At first blush, except for a real good dent in the front 
> thread, I will  say nothing else got hurt. The glass is 
> nice and clear, better than  most user TRs.
>
> But as soon as I do, someobody will post back saying that 
> the alignment  could have gotten knocked out of whack, and 
> they'd be right. But at  11x14 and contact printed to 
> boot, I doubt that you'd notice any  misalignment when you 
> use a strong orange filter.
>
> I think the school was thinking of buying the lens anyway, 
> so I don't  believe the situation is as achromonious as it 
> might appear, though I'm  not part of the negotiations.
>
> thanks to all for the help.
>
>
> Les
>
   It probably has not gotten out of alignment and as I said 
earlier the ding can be removed with a tool available from 
several sources. I can't find my Gundlach-Manhattan 
catalogue right now (will look some more) but I don't think 
this is a Rapid Rectilinear. Ernst Gundlach designed a lens 
he called the Rapid Rectigraph which had three cemented 
elements instead of two but the front pair was really only 
the single element of the R-R split and cemented to get 
around the patent. Having said that this lens _might_ be an 
R-R type. R-R's were occasionally made as triple 
convertibles. However, the corrections lost by the lack of 
symmetry would lead to not very good image quality. R-R 
lenses are not anastigmats but can produce surprizingly good 
images when stopped down. The residual astigmatism was often 
minimised by introducing some curvature of field to average 
out the error between the two fields.
   The Turner-Reich, according to Kingslake, was probably 
designed by Ernst Gundlach and the design looks like one of 
his. Its essentially a Convertible Protar with the same 
trick of splitting one of the elements into two. That gives 
it five elements per cell. Kingslake thinks very few were 
correctly centered. In any case, its performance is inferior 
to the Protar (I have both), especially the individual cells 
which in the T-R seem to have a great deal of lateral color.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk at ix.netcom.com