View Full Version : 48" 1219mm f12.5 Bausch & Lomb-Zeiss APO Tessar

2-Sep-2013, 10:20
Does anyone have any info on this lens?

Series VIII
Patent: Feb 24 1903
Serial: 1861317

I was told that it's a process lens.

Going to try to give it a go with landscapes. If I can build a back that is big enough. :cool:

8x10 user
2-Sep-2013, 10:34
looks like half a lens to me.

Dan Fromm
2-Sep-2013, 10:47
Look here, http://www.cameraeccentric.com/html/info/bauschlomb_8.html pages 43 and 56. The coverage claimed seems to be for 1:1, it should cover half that (16 x 18) at infinity. But, as has been pointed out in a recent discussion, (a) you have to ask the lens to know for sure and (b) the rated coverage may be conservative.

It is an older design than the Apo-Tessars that Arne Croell discusses here: http://www.arnecroell.com/publications . B&L seems to have stopped engraving "Zeiss" on the lenses they made under license after 1915.

2-Sep-2013, 11:12
Yes this is a process lens. But at infinity its image quality is also pretty good so the lens is quite nice for landscapes. (My only objection would be the brass barrel that is really a lot heavier then the later aluminum ones.) I've not put my hands on this particular glass but I've a lot of experience with others of the very same type. Your lens is sharp enough for the negatives to be enlarged so you are free to use it with smaller formats too, not only ULF. But don't neglect making a big enough lens hood if you are not fond of very low shadow contrast as your specimen is not coated.

When stopped down enough, a Tessar of this type would make all the field it illuminates nicely sharp up to the edges (a thing that the most common Celor type process lenses can't achieve).

Also, a lens of that vintage usually has each of its glass elements in individual brass rings with threaded mounts. If so, your also get the opportunity to enlarge the distance between the front and the second elements at will; that would introduce some negative spherical aberration which improves the background blur significantly (though sacrificing some of the sharpness).

9-Sep-2013, 20:54
Thanks for the input!