Re: [APML] 4x5 astrocamera (again?)

["Bobby Middleton" <bobm@koyote.com>]

Yes the color does look wonderful. Beautiful shots Wei-Hao. With 90 min plus
exposure at f/4 with 13,000 feet of atmosphere beneath you I'd say you're
giving the equipment and film the best opportunity they'll get short of a
session at prime focus of the Hubble. I've seen other good work with E100S.
Is it discontinued?
Bobby Middleton


----- Original Message ----- 
From: "Wei-Hao Wang" <wang@IfA.Hawaii.Edu>
To: <astro-photo@seds.org>
Sent: Thursday, May 06, 2004 5:33 PM
Subject: RE: [APML] 4x5 astrocamera (again?)


> Hi Kirk,
>
> It's difficult to answer.  First, I use E100S a lot but almost never
> without pushing.  Even when the lens is fast (F2.8-F4), I tend to
> decrease the exposure a little and push it by 1 stop.  I just want a
> little more contrast.
>
> With slow lens (F5.6) and two hours of exposure, the quick answer is,
> push no more than 1 stop.  Two hours are usually enough for E100S at F5.6.
>
> A more detailed answer depends on the sky brightness (the light
> pollution) at your site.  If the sky is very bright, you may want to
> decrease the exposure to make the sky look dark on the slide but
> push 2 or even 3 stops to bring up the nebulas, Milky Way, or whatever.
> Think it in this way:  The brightness on celestial bodies are fixed.
> If the brightness of the sky background increases, then the contrast
> between the background and the celestial bodies decreases.  This is why
> we need to push to compensate the contrast loss.
>
> This is not that critical if your final productions are digital files.
> You can do lots of things to modify the brightness and contrast.
> However, this is critical if you want to view through a light box on
> your original slides.  In this case, the exposure-push combination needs
> to be very accurate to produce nice looking slides.
>
> Check out these:
> http://www.ifa.hawaii.edu/~wang/gallery/picutres/summer_mw-2003.htm
> http://www.ifa.hawaii.edu/~wang/gallery/picutres/cassiopeia.html
> Isn't the color of E100S beautiful?  These are just from 645 and 67
> formats.  A well exposed 4x5 E100S will look awesome on a light box.
>
> Cheers,
>
> Wei-Hao
>
>
>
> >From: Kirk Carbo <kcarbo@lobosservices.com>
> >To: "'Discussion of Film Astrophotography'" <astro-photo@seds.org>
> >Subject: RE: [APML] 4x5 astrocamera (again?)
> >Date: Thu, 6 May 2004 16:56:41 -0500
> >
> >Wei-Hao
> >
> >That's very interesting.  I have thought about doing more wide field
shots
> >with my view camera and slide film.  I was thinking a 4x5 slide is so
large,
> >it wouldn't even need to be printed.  It would look beautiful on a light
> >box.  Are the on films being pushed needing 2 hour exposure or one hour?
> >
> >Kirk Carbo
> >
>
> ______________________________________________________________________
> Wei-Hao Wang  :)
>
> Institute for Astronomy at University of Hawaii
>
> Address:                       Phone: 808-956-9867
> 2680 Woodlawn Drive            Personal Website:
> Honolulu, HI 96822             http://www.ifa.hawaii.edu/~wang
> ______________________________________________________________________
>
>
>
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