Re: Vignetting on -DS 1-stop?

[Herb Chong]

wide open, even the FA* lenses show some vignetting, as much as a half stop 
or slightly more. inexpensive lenses can show up to 1.5 stops easily wide 
open. as for even illumination, you really need to measure carefully to be 
sure. the eye is pretty insensitive to half stop differences.

Herb....
----- Original Message ----- 
From: "Cory Papenfuss" <[EMAIL PROTECTED]>
To: <pentax-discuss@pdml.net>
Sent: Saturday, March 26, 2005 11:04 AM
Subject: Re: Vignetting on -DS 1-stop?


Pentax DA 18-55, f/3.5
Vivitar 28-105, f/3.5 through f/8
Vivitar S1 (Komine) 70-210mm, at 70 through 210, f/2.8 through f/11
2x doubler
 I didn't do much of a fancy test, but wall, paper, etc were different 
test setups.  No real careful illumination, but close enough so it should 
have been pretty consistent.