Doppel - Anastigmat Foyer 1:4.5 18 x 24 Foyer 280mm

[Stijn]

this lens has on top of it "Doppel - Anastigmat Foyer 1:4.5 18 x 24 Foyer 280mm N? 9905 Optishe Institut M unchen" on top of it.

it is a very nice looking peace, and it is has a nice weight. and at the top and bottom ellements it has small air bobbles on top of it.

1. could someone tell me which is this is a brand less lens? 2. I posted this lens aswel on Photo.net, and I got some responces, someone told me that these air bobbles are a proof of quality, could someone specify this? 3. this is a 1:4.5 which I think is a fast lens, (concerning LF) but as this len s has a carbon made hood, which is used as shutter, how can I get the right timi ng? are there anywhere shutter that I can buy for this lens? (they have to be b ig, the lens is about 7cm (about 3") of pure glass in diameter.) 4. has anybody any experience with this lens? 5. ... (any other information about this lens is very welkom)

thanks all for helping me.

[Dave Willison]

I'm not sure of the specific brand of lens. From the language it appears to be a German lens manufactured in Munchen. Several German companies appear to have made lenses in Munchen, including Ludwig Muller, Leitmeyer, and Hugo Meyer. However, I can't find a listing with your lens and one of these specific manufacturers. Unfortunately, older brass barrel lenses often carry few markings indicating the maker, the focal length, etc.

The lens design appears to be a double (doppel) anastigmat. This type of lens was designed by Emil von Hoegh in the 1890s and marketed by Goerz. The design was corrected for spherical and chromatic abberation and had a flat field free from astigmatism. The Goerz version of the doppel anastigmat was later marketed under the acronym Dagor.

From your description, the lens has a maximum aperture of appromimately f4.5. I would check this to make sure that the aperture markings match the modern system of f stops (22,16,11,8,5.6,etc.). Divide the focal length by the maximum opening in mm. If your lens if f4.5 wide open, the diameter of the lens opening should be approximately 62mm (62x4.5=279). You also note that the FL is 280mm. Given the age of the lens, I would guess that it covers 5x7 but not 8x10. It could be designed for some european plate size but I'm not sure. Perhaps the 18x24 marking refers to the plate size covered (18cmx24cm??).

To operate the lens, you can cover with a lenscap, hat, etc. or purchased a Packard shutter. For new Packard shuters check the floowing link:

http://www.hubphoto.com/photographic-products.htm

Used shutters are also available form a numbers of sites, including Midwest Photo, Equinox, PGSYS, etc. If you need information on mounting the Packard, drop me an e-mail.

A new Packard will cost about $100-150 after you purchase the shutter, tubing, a bulb, etc. Using a lenscap or hat reduces the cost, but you will probably need to purchase a ND filter and mount it behind the lens. The lenscap method works best when exposures are at least 2 seconds, so a ND filter that adds 4-7 stops should allow you to shoot in daylight. I hope this helps.

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

[David F. Stein]

Good answer. In the good old days, many lenses were marked with an effective focal length and the coverage: so this lens covers 8x10-reasonable for the focal length. I believe the 4.5 aperture marking corresponds to a modern 6.3, which would make sense for the Dagor. Enjoy an historic len

[Stijn]

thanks Dave for the historical information, I check the apparatuer of the lens, and it is marked, 4.5/6/8/11/16/22/32 concerning the 280mm, if I take the exact discription of the lens then it is; "280 N/M" or "280 M/M" the first N is very difficult to see the difference. I suppose this is the focus lenght, not?

[Doug Paramore]

Stijn: As to the bubbles, back years ago the highest quality optical glass was almost impossible to make in larger sizes without bubbles. The old photographers used to look for the bubbles as an assurance of quality glass. The bubbles have not effect on the image.

Regards,