[APML] Pushing and Mars

["Warren A. Keller" <warhen@mindspring.com>]

Gary,
       Seems like you've misunderstood the reason for pushing. As others
have said, this is to gain dim data for deep sky, at the expense of some
grain increase. In that regard, you are using a Bulb setting and the ISO
setting is meaninful only to a metering system. A bright planet needs no
push.

Everyone's right, film will be tricky but definitely worth the shot during
this monumental period! Here too, you'll be using a hat trick with a
mechanical shutter, as it sounds like you have an SLR. Your exposure will be
under a few seconds, so you'll need to do that to avoid vibration. Also,
lock up your mirror after focusing and centering.

Slide is a good choice because of high contrast and low grain, but slide's
unforgiving- once you burn it out, it can't be recovered. Exposure will vary
on what f/ratio you're working at, and you'll want at least f/30 to get a
decent image scale. You can use a 5x Barlow or e.p. projection, and whatever
the combo will determine exposures. You should bracket these and check
focus.

To paraphrase Covington, an f/10 SCT, with a 5x Powermate and E-200 would
put you at 1/8 second, which ain't bad.

As others have said, seeing is everything, so the shorter the exposure the
better. I hate this expression, but it seems appropos- "Hope this helps".

Warren A. Keller
www.billionsandbillions.com


I have 2 newbie questions for the group.
1.  When pushing slide film are you supposed to change the ISO setting on
the
camera to reflect your push, or leave the setting at the correct film ISO
and
let the developer do the push?
2.  What would be a good film speed to use for pics of Mars?  Fast (800)
with
short exposure or slow (200) and a longer exposure?
I'd appreciate any guidance anyone can give me.

Gary Hatfield
Thaxton, VA


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