Recent content by Dan Fromm

Thanks for the explanation. I misread the original post.

This all depends on what "circle covered" means. In the bad old days it often meant "circle of good illumination." In the good (?) new days it usually means "circle of good definition." "Good definition" can be somewhat subjective. What a 150 mm lens might do is irrelevant. You're buying a...

Please visit the link in post #7 above to see Schneider's view. By the way, since the lens the OP is talking about has focal length in cm, not mm, it is pre-WW II.

By all means try, but be aware that Schneider claimed that the lens covers 4.25" x 3.25". See https://web.archive.org/web/20170123075959/http://cameraeccentric.com/html/info/schneider_3.html

Brian, some #3A FPKs have f/6.3 Tessars in Compound shutters. I've shot some of these lenses on 2x3. They're better than good enough.

Thanks for the reply. It depends. I'm sorry, but which apertures do you want to use? Thanks to the inverse square law, 30 - 40 feet requires quite a powerful flash. So, for that matter does 15 feet. I don't mean to insult you, but you should learn how to use Guide Number arithmetic. You...

It depends. Back when I shot flowers, insects and such in broad daylight with ISO 25 Kodachrome and low power flashes at short flash-to-subject distances. I got consistent good exposure. Fill flash? More powerful flashes such as Vivitar 283s and auto-exposure. These days I use relatively...

I hate to use them but putting an ND filter in front of the lens is equivalent to putting slow film behind it. OP, which film(s) do you want to use, which aperture(s) do you want to use and which subjects? And what range of flash-to-subject distances to you want to work at? Without this...

Your 6"/2.5 AE is typical of nearly all of the ones I've seen (Kodak and B&H). Barrel mount with fixed aperture. Like you I've seen a very few in normal barrels with diaphragms, but these are very rare. If you're serious about making your lens more usable, approach SKGrimes about putting it...

I'll ask the question again. Have you measured how long it takes for a cleared lens with thorium glass takes to need clearing again? If so, which lens and how long? I just pulled out a 30 cm f/9 Taylor Hobson Cooke Apotal that I cleared ~ 20 years ago under a UV-B compact fluorescent (not the...

Theory, not observation. Do you know how long a lens with cleared thorium glass takes to yellow again? Name a lens, give a time.

Why do you believe this? Have you seen it happen?

Why do you believe this? I ask because I have and use what I think is an ES-1. I described its key measurements in post #12 above.

Joe, there may be a problem with your site. Firefox told me this: Advanced What makes the site look dangerous? Sites use certificates issued by a certificate authority to prove they’re really who they say they are. Firefox doesn’t trust this site because it looks like the...