Please help ID my Tessar..

[Robbie Bedell]

I have been doing research to help determine the focal length and any other relevent information about my B&L Zeiss Tessar. Some have helped already and I have it narrowed down but I am still confused as there are so many IIb models. I am posting a photo so if any of you can help it would be great. Thank You! Robbie

[Glenn Thoreson]

Since it came off a 3X5 postcard size camera, I would estimate it to be 170mm. Most of them were made for portrait shooting, thus a rather long lens for the format. Best thing to do, if you want to be more exact, is to mount it on a camera. Focus at infinity and measure from the film plane to the aperture blades. I wish my Volute shutter looked that nice. Mine has been used so much the engraving on the front is all but worn away. Is that a 6.3 version? Should be an outstanding performer! :D

[Steven Tribe]

This IIb tessar (called size 5k) has a focal length of 6 7/8" (175mm). To check - the diameter of the lens should be 1 3/8". In camera eccentric listing!

[Robbie Bedell]

Thank You so much guys for your input. I did some experimenting today, which, I know, I should have done long ago, but... I compared my Tessar to my modern 150mm Caltar and then my 210 G-Claron. Just by 'guess and by god' I estimated it to be 180 mm, so I guess Steven I was not far off your 175mm mark.

Steven: Thank you for the "5k". That's what I thought from looking at the Camera Eccentric info, but I wanted to be sure.

This is an amazing lens. Its brightness and sharpness rival my Caltar. I will be using it more and more. I just cannot beleive it is more than 100 years old!

The other lens I have been playing with is the 'Centar' (another ancient lens) referred to in a previous thread. It has no maker ID, but the amazing thing about it is the fact that when I put my 210 G-Claron on the camera and composed, etc., then switched to the 'Centar' the camera was absolutely in the same focus and framing, so it is a 210. It is not as contrasty as the G-claron or the Tessar but is plenty sharp and should be great for lots of stuff, portraits, etc.

Again, thank you!

[Robbie Bedell]

Glenn, it is a 6.3...