On 15 Nov 2004 at 7:23, J. C. O'Connell wrote:

> Unless the 125mm zoomed out to 62.5mm at 1:1, it is
> going to need exposure compensation.

Of course you are correct, I was simply drawing a relative comparison to 
another lens.

> What you have is essentially
> a variable aperture zoom with that lens, how do
> do you know what exposure compensations to use?

I don't really care but I do know now that relative to a "non-zoom" macro lens 
it requires about an extra half stop when approaching 1:1. I haven't used 
external meters for macro photography since the late 80's. Then I had a 67 and 
bellows and I was glad to get my hands on a TTL prism.

> Does the lens barrel have exposure compensation
> markings on it?

No
 
> 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...

..or you (I) could use the TTL metering, which I do quite successfully.


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

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