Re: Nighttime and astrophotography with IR

["Willem-Jan Markerink" <w.j.markerink@xxxxx>]

On  3 Sep 96 at 20:46, Robert Long wrote:

> |Who's going to contribute info on best ASA to use? I'm sure the colder
> |weather will make a difference....dont' you think?
> 
> I assume Willem continues to use something in the 200-300 region for
> HIE.  But perhaps the real question is just how to meter show scenes.
> W-J?

Ah, you mean to compensate for the white snow?
Not sure how many rolls I shot with #25, my latest series were on
#70, and my next shots will be on #89B. With at least the #25 I used
400 ASA 'TTF', on both my former Minolta 9000 & 7000 and on my EOS-1;
but on manual, or with at least a +1 snow compensation in auto mode. 
As for external meters (I never have been fond of putting the filter 
on and off for no-filter TTL), my rule of thumb is 400 ASA to start 
with, add +3 for red, +4 for #87, and +5 for #87C. Since the bracket 
is at least +1/0/-1, I mostly get the shot I want. 

And after seeing a constant 1/60@xx (roughly) as a result of that
(#87C), I don't bother too much with the external meter any more, at
least not for my panorama shots. And without a tripod, opaque filters
are hardly usable with a telelens and a SLR (PS: that Combat Graphic
70mm camera did also come with a 200/3.5 lens, range finder
coupled....8-)), so the problem with the more different lighting of
details hardly exists, since those shots are always taken with a
normal red filter, one that allows TTF readings. Will have to see if 
that still works with the #89B. It did work with the #70.



--
Bye,

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The difference 
between men and boys
is the price of their toys

<w.j.markerink@xxxxx>
[note: 'a-one' & 'en-el'!]

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Topic No. 4