Printable View
A quick web search doesn't seem to bear much relevant fruit.... anybody got old catalog pages or such ? I picked up a B&L "11x14" one today, in a dial-set Ilex shutter. Too dark out to see anything on the GG, so, just curious what anybody might know?
Hey Tracey I did find this in a Zeiss catalog on APO Tessar. Maybe it will help?
OK Tracey, I know this will help. From the 1915 B&L 1915 catalog. The APO Tessar Process lens.
Funny lens, seems to be (only) around 14" FL.
Engraving reads:
"11x14 BAUSCH & LOMB - ZEISS APOCHROMATIC TESSAR, Series VIII. Pat. Feb. 24, 1903."
The rear cell is marked "BACK"
I'll post a photo later today.
Tracy, Arne Croell has written about post-WW II CZJ Apo-Tessars. See http://www.arnecroell.com/publications This isn't exactly what you want but its the closest I know of.
Allen Rumme has a little about B&L Apochromatic Process Tessars, see http://www.allenrumme.com/lensdb/Process.html . I view everything on his site with suspicion but the information he's tabluated isn't all wrong. If your lens' focal length is around 18", it is the second one in his list.
On general principles, which aren't always correct and applicable, assume that its rated coverage is for 1:1 and that infinity it will cover 6.5 x 7.
I just mounted an f/9 14" coated apo tessar made by (???) but private labeled Carl Meyer. Plenty of coverage on 8x10, even with movements, but that's the biggest
size camera I have. It's excellent at infinity, but I wanted to use it more for the specific out-of-focus background qualities which seem more pleasant than my dagor or plastmat of equivalent focal length render. I've alreay made a print. The specs on process lenses were typically given for both 1:1 and at a moderate copy distance. But these were defined by printing industry standards, in which retention of apochromaticity as well as exact dot shape clear to the corners factored in. These are much tighter standards than for typical taking photography like we engage in. Therefore the usable image circle is often much larger than the published one, particularly at apertures smaller than the f/22 from which the published specs are standardized. But there are just so damn many flavors of these things in this focal lengths which were made over the years, up till process lenses began to be mainly dialytes rather than tessars.
Thank you both !
I will pop it on the 8x10 today and see what FL and coverage look like at infinity.
Of course tessars tend to fall off in resolution more at the extremes than dialytes or plastmats, so what constitutes the definition of acceptable image circle often differs between contact printers and people doing enlargement. But even a 20x24 print is a very modest enlargement for 8x10 film. Just gotta test these things,
really. Here I was fretting about spending serious bucks gambling on some lens effect I had no personal experience with... then I remember I had some old horse
traded process tessar lying around somewhere, yet in mint condition, which turns out to be exactly what I needed.