Vilar f6.8 on HEAG 11 (1920's), Bob V 1920. This has been described as excellent in a 1998 report, and said to be 5 glass: but a 4-glass seems more like. (Shutterbug, 1998) Frerk says it is a 4-glass dialyt type. It was one of the cheaper versions on the Heag 11, below Ernar and Ernon. It was noted as an 135mm lens at No82,89x on a 9x12cm Tropical. It was used in B.J.A. 1926, p676 etc. on Bob V rollfilm in several sizes such as VP, 2.25x2.25, 2.5x3.5in and 4.25x2.5in. (B.J.A. 1925, p698 on Bob V abd Heag VII,etc).
Yes, but would they call an asymmetric 5/2 design "Doppel-Anastigmat"? Maybe.JPD, I'm not going to do your homework for you, but look for Protar cross sections. I think you'll find that "Protar" includdes 4/2 and 5/2 types.
It means that it probably has four lenses. It you look at
the lens from an angle, does it look like the picture 1 or 2?
Have you ever tried? It isn't difficult.It would be really helpful if someone wrote an article with photos showing how to count reflections; with photo examples of each lens type. It would be a great reference source here.
You can see the shape of the elements (or cemented group).What is the difference between the pictures? I am not sure what to look for. Maybe it looks more like the first picture.
/matti
Have you ever tried? It isn't difficult.
You can see the shape of the elements (or cemented group).
Picture 1. is a dialyte. A Tessar or simple triplet would also look like that:
() )(
Picture 2. is a Dagor. It has three cemented elements in front of the shutter, and the group in one piece looks like this:
( (
A gauss design looks similar as the Dagor, but on them you would see two reflections bowing outwards.
(( ((
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?