This is a question for all you lens experts. I have obtained a Goerz lens via eBay that was supposed to be a "Red Dot Artar". The seller did say that he was sure it was a "red dot", but could not verify this. Well, being one to never resist an oldie, I purchased it. However, it does not conform to what a 210mm "red dot" should be.

There are no markings on this lens other than "C.P. Goerz Am Opt Co" and the serial number. It is an f/6.8 lens. Red dots are f/9.0 - however both the Gold Ring Dagor and Gold Dot Dagor (240mm) are f/6.8

I suspect that it is in reality one of the "golds", but cannot verify this. Is there another way to identify this lens, like by serial # ? I have found some history on Goerz lenses on this site and others, but nothing that is any help. Any suggestions or tips?

Many thanks.

-- Matt O. (mojo@moscow.com), September 07, 2000

Answers

Hi

I am no expert on Goerz lenses, but try posting this to the USENET group, rec.photo.equipment.large-format if you don't get any useful responses here about this.

There are people there who would probably be able to tell you.

Regards

-- KH Tan (kahheng@pacific.net.sg), September 07, 2000.

I have a 12" Gold Dot Dagor, and it has a gold colored dot embedded in the name plate (it doesn't wear off). The later gold ring varieties have a gold colored rim. The Red Dot Artars have red dots on the name plate.

-- David Goldfarb (dgoldfarb@barnard.edu), September 07, 2000.

Goerz American Optical Co. made a lot of lenses under government / military contracts and in some of these contract jobs there were no trade names engraved on the lenses. Sounds like you have a Dagor as the Artars were certainly slower designs. Check that the same serial number is on both front and rear elements. There are some sketchy records on serial numbers but I believe they just reveal year of manufacture. If you feel like disassembling the lens rings and examining the elements, look for a Dagor to have symmetrical front & rear elements each consisting of three lenses cemented together so well that it appears to be one lens. The Artar's symmetrical front and rear elements are made from two air-spaced (no cement)elements which separate easily when the rings are removed.

-- C. W. Dean (cwdean@erols.com), September 07, 2000.

What's the serial number? Is the lens coated?

-- neil poulsen (neil.fg@att.net), September 08, 2000.