Unless the 125mm zoomed out to 62.5mm at 1:1, it is going to need exposure compensation.
What you have is essentially a variable aperture zoom with that lens, how do do you know what exposure compensations to use? Does the lens barrel have exposure compensation markings on it? At least with a fixed focal length and aperture you can calculate the correct compensations based on magnification or bellows extension, but with variable aperture those techniques won't work... JCO -----Original Message----- From: Rob Studdert [mailto:[EMAIL PROTECTED] Sent: Monday, November 15, 2004 7:31 AM To: [EMAIL PROTECTED] Subject: Re: A Question About Macro Lenses On 15 Nov 2004 at 6:25, Lon Williamson wrote: > I only own older "extension only" macros; from what I gather from > reading, "zoomy zoom" macros suffer no light falloff when > close-focusing but may lose a bit of focal length. Sounds like a good > trade-off to me. I'd say that's a pretty accurate assumption WRT FL, my V125/2.5 looks to be just a tad over 100mm FL when approaching 1:1 mag. However in a recent little test I made comparing my V to an older bellows lens the V seemed to need about a half stop extra exposure a any aperture to equal the old lens exposure wise. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
