Re: [APML] Short Provia 400F Exposures (was: Rho & M8M20)

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

Question for Provia pushers:
Provia seems a bit weak in red to me without pushing. Does a 1 stop push fix
this problem?
Bobby Middleton


----- Original Message -----
From: "Chris Cook" <ccjd@ix.netcom.com>


> I've only pushed 400F once at +2 and found that the film had a strong red
> shift if exposed to the sky fog limit.  It was difficult to remove during
> processing.
> My recent M101 shot is a straight exposure on 400F, no push:
>
> http://www.abmedia.com/astro/current/m101-fs102.html
>
> My plan is to only shoot this film straight or with a +1 push.
>
> Chris
>
> ----------------------------------
> Chris Cook
> Astronomical & Nightscape Photography
> www.abmedia.com/astro
>
> -----Original Message-----
> From: Jon Kolb <jkolb@datawest.net>
> To: 'Discussion of Film Astrophotography' <astro-photo@seds.org>
> Date: Saturday, May 31, 2003 5:50 PM
> Subject: [APML] Short Provia 400F Exposures (was: Rho & M8M20)
>
>
> >In a previous post, I mentioned that only 15 minutes at f/4 will record
> >quite a bit on 400F with a one stop push.  Here's a manually guided
> >sample shot to show what can be done.  I was doing some example shots
> >with this lens because I was considering selling it, but now that I
> >finally focused it with a KEF and I see what it can do, I think I'll
> >keep it around.  This shot is actually blown out a bit and is clipped
> >very slightly at the high end, but as an example of the film's ability
> >on a short exposure I think it's OK.
> >http://home.datawest.net/jkolb/m8-m20_300mm.htm
> >
> >The 400F also is good at recording star fields.  Here's one I did at
> >f/7.9 for only 15 minutes just to see how tight I could get the stars
> >(since we know that chrome films will tend to blow out stars on long
> >exposures), and it's also a one stop push.  I think the star colors look
> >more natural in this shot than in longer exposures I've done in the
> >past, and M11 obviously has better resolution than it would with blown
> >out stars.
> >http://home.datawest.net/jkolb/m11_tmb152.htm
> >
> >For comparison, here's a much longer shot, 90 minutes, with a one stop
> >push again.  The stars are somewhat bloated, but it's also cropped and
> >enlarged from the original.
> >http://home.datawest.net/jkolb/m45_tmb152.htm
> >
> >I have never tried pushing this (or any) film 2 stops, but I might do
> >another round of test shots just to see what happens.  Right now it's
> >just nice to get a clear night for a change.  For a one stop push, I'm
> >using the following exposure times for nebulous targets...
> >f/4: 15 - 30 minutes
> >f/6.4: 45 - 60 minutes
> >f/7.9: 60 - 90 minutes
> >
> >Sincerely,
> >Jon Kolb
> >Adventures in Astrophotography
> >http://home.datawest.net/jkolb/
> >jkolb@datawest.net
> >
> >
> >
> >_______________________________________________
> >Astro-Photo mailing list
> >Astro-Photo@seds.org
> >http://seds.org/mailman/listinfo/astro-photo
> >
>
> _______________________________________________
> Astro-Photo mailing list
> Astro-Photo@seds.org
> http://seds.org/mailman/listinfo/astro-photo

_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo