Test examination needs also a look for stress induced birefringence or in german Spannungsdoppelbrechung. This test is very simple and very necessary for longer focal lenses like Dagor-(Protar,...
Type: Posts; User: ludwig; Keyword(s):
Test examination needs also a look for stress induced birefringence or in german Spannungsdoppelbrechung. This test is very simple and very necessary for longer focal lenses like Dagor-(Protar,...
Nodda Duma :
You write - A methodical approach would be to characterize the aberrations in the lens subgroups being tested.
This was once my ability, Zeiss ask me once in around 1990 to...
Dan Fromm and Nodda Duma :
Thanks for datas. At first is my interest to collect informations about adapters - there is the cheap mass-market and the expensive market like Cine-Industry and...
Something here seems not to compute. According to the bible, 10th edition, the Graflex SLRs with the shortest flange-focal distance are the RB Ser. D and Super D, both at 6 3/4". It isn't clear...
Nodda Duma wrote on 10-Feb-2015, 22:09 here in this forum :
edited the thread title to clarify this is a build-your-own-lens project.
Oren:
infinity-distance last glas-surface to screen is s'F'
s'F' without converter 142,5mm, flat field, vignetting starts few mm before 5x7''
s'F' with converter 148,5mm, flat field, vignetting...
The lens-collectors here and lens-designer will know the old wideangle-aplanats or other aplanats with their heavy astigmatism, so much koma sometimes (I mean the older before 1890, not those, which...