Re: [APML] Exposure times?

[Roland Roberts <roland@astrofoto.org>]

>>>>> "Mark" == Mark Bohrer <lurchl@ix.netcom.com> writes:

    Mark> 1. Are the two exposure ranges sufficient?

Well, the 999 minutes is probably excessive 8-)

For deeps-sky images, nearest minute is probably fine.  Among other
things, exposure changes usually have to be a factor of two to see a
significant difference in the result.  Bracketing exposure times by
sqrt(2) corresponds a half-stop aperture change, so that gives you
some idea of the level of granualarity needed.  I would say only the
1--999 minutes is needed.  If you are going to do planetary shots,
then the 1--999 second range might be useful.

    Mark> 2. Does anyone even use mechanical cameras and film anymore?

Does anyone here not use them?

roland
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