"Brian McMahon" <brianmapple.mweb.co.za> writes:
It's strange to hear you talking about "stopped down" in the context of>Thanks Lionel and Bart for your replies. I suspected trial and error might
>be the only way. I was hoping there would be a stopped down auto mode, as
>there used to be on my old A-1, for stopped down aperture priority
>automatic, or stopped down manual metering. That was when T mount lenses
>were still quite common, of course and I found it useful on the lenses of
>that type that I owned.
astrophotography, because normally there is no aperture diaphragm to
stop down. In prime focus photography, which is what you use a
T-adapter for, the telescope objective focuses its image directly onto
the film or electronic sensor. There's no telescope eyepiece and no
camera lens in the optical path, and no aperture to stop down.
Of course, taking aperture equals viewing aperture, so you want to meter
in the same mode that you'd use with a camera lens stopped down to
taking aperture. This is probably what you mean.
Ouch.>Regrettably, tonight's planned session has been called off, as my friend was
>rushed off to hospital in a coma, after being attacked and stung repeatedly
>by a swarm of bees. African bees have a potent sting. He's OK now though and
>is likely to be discharged this evening. We'll try again another evening in
>a few days time.