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Leica Users Group, 2012/11/24
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Subject: [Leica] So, wouldn't a 50mm Summicron LTM or 35mm f2 ASPH LTM be the best enlarging lens on earth?
From: red735i at verizon.net (Frank Filippone)
Date: Sat, 24 Nov 2012 15:57:52 -0800
References: <BLU0-SMTP101498BE1476A93A8E970D38C590@phx.gbl><CAFfkXxtGO91jJ_FhqmdNoGOxrmPPpVxqUJiUf0Xqoij4fFhpWQ@mail.gmail.com><CA0B5E6A-AD00-4B28-925F-8FD3182EAA72@mac.com> <CABmfTOUOykVV7UJyZA7hbuBk+VAKVJhE388dfmKVcos9PNEinA@mail.gmail.com> <ACE934EC4ABC4AEDB277DB5230A79BB8@Equibox> <3390316F-5ECE-4F38-840B-B4C27B5BED0C@usjet.net>
Physics....
White light is composed of all the colors.
B+W Paper has a spectral response.
If you want the theoretical best you can do, then you need to either shoot
light at the paper from a single wavelength or second best, make sure all
your wavelengths are focused at the same plane (negative stage).
Definitions of APO vary..... all over the place... 3 (unstated )
wavelengths, 4 ditto, from x to y nanometers, etc.
There is no scientific definition, AFAIK.
Frank Filippone
Red735i at verizon.net
Does an apo lens bring all three primary colors to the same focus point, as
opposed to just two out of three for a non-apo lens?
If that is the difference, why would an apo lens offer any advantage for B&W
printing?
Replies:
Reply from red735i at verizon.net (Frank Filippone) ([Leica] So, wouldn't a 50mm Summicron LTM or 35mm f2 ASPH LTM be the best enlarging lens on earth?)
Reply from benedenia at gmail.com (Marty Deveney) ([Leica] So, wouldn't a 50mm Summicron LTM or 35mm f2 ASPH LTM be the best enlarging lens on earth?)
In reply to:
Message from vick.ko at sympatico.ca (Vick Ko) ([Leica] So, wouldn't a 50mm Summicron LTM or 35mm f2 ASPH LTM be the best enlarging lens on earth?)
Message from sonc.hegr at gmail.com (Sonny Carter) ([Leica] So, wouldn't a 50mm Summicron LTM or 35mm f2 ASPH LTM be the best enlarging lens on earth?)
Message from imagist3 at mac.com (George Lottermoser) ([Leica] So, wouldn't a 50mm Summicron LTM or 35mm f2 ASPH LTM be the best enlarging lens on earth?)
Message from benedenia at gmail.com (Marty Deveney) ([Leica] So, wouldn't a 50mm Summicron LTM or 35mm f2 ASPH LTM be the best enlarging lens on earth?)
Message from jon.streeter at cox.net (Jon Streeter) ([Leica] So, wouldn't a 50mm Summicron LTM or 35mm f2 ASPH LTM be the best enlarging lens on earth?)
Message from robertmeier at usjet.net (Robert Meier) ([Leica] So, wouldn't a 50mm Summicron LTM or 35mm f2 ASPH LTM be the best enlarging lens on earth?)