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

["Chris Cook" <ccjd@ix.netcom.com>]

Possibly.
I'm planning on trying this during the next clear night.

Chris


----------------------------------
Chris Cook
Astronomical & Nightscape Photography
www.abmedia.com/astro

-----Original Message-----
From: Bobby Middleton <bobm@koyote.com>
To: Discussion of Film Astrophotography <astro-photo@seds.org>
Date: Sunday, June 01, 2003 11:32 AM
Subject: Re: [APML] Short Provia 400F Exposures (was: Rho & M8M20)


>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
>> >
>> >
>> >
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>> >
>>
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