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Re: [APML] OT: digital vs film in a Schmidt, was: - fast comets
Thanks, Loke, that's what I thought. It makes no sense, optically or
mechanically, to try to put a digital camera body in a Schmidt. In a 14 inch
Fastar or Hyperstar might be a different story, but I don't think I've ever
seen an image from one of those that really, really, compared to a good
Schmidt image. (I will now duck the flames ;-)).
Happy New Year to All and here's hoping for a good Mars landing!
Bert
Bert Katzung
katzung1@comcast.net
www.astronomy-images.com
----- Original Message -----
From: "Loke Tan" <tan@cox.net>
To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
Sent: Monday, December 29, 2003 2:52 PM
Subject: RE: [APML] OT: digital vs film - fast comets
> Bert,
>
> Yes, any of the 35mm digital or film cameras are too large to be
positioned
> inside our available 5.5" or 8" Schmidt cameras. Here is a picture of how
> the pros do it for a larger Schmidt camera:
>
> http://starryscapes.com/tmp/cerro_tololo_schmidt.jpg
>
> This is a modified focus position of a large Schmidt at Cerra Tololo
> observatory in Chile. I believe it's a 20" but I could be wrong. The
Schmidt
> was modified with what appears to be a Newtonian focal position. The CCD
> camera is behind the black shroud. I was told that there are field
curvature
> correction optics behind the shroud as well. I saw some fo the CCD images
> taken with this setup. The stars were not pinpoint, but the Astronomer in
> charge of modifying the instrument said that this was fine for what they
> were using it for.
>
> Loke
>
>
>
>
>
> > -----Original Message-----
> > From: astro-photo-bounces@seds.org
> > [mailto:astro-photo-bounces@seds.org]On Behalf Of Bert Katzung
> > Sent: Monday, December 29, 2003 10:55 AM
> > To: Discussion of Film Astrophotography
> > Subject: Re: [APML] OT: digital vs film - fast comets
> >
> >
> > Hi Chris:
> > I will be interested in Loke's answer, but my thought is that even the
> > smaller-than-35mm size chip in the 300D/10D digital cameras will
> > suffer from
> > the field curvature of the Schmidt. In addition, I don't think any
Schmidt
> > made allows a whole camera body to be inserted into the scope.
> > My 2 cents----
> > Bert
> >
> > Bert Katzung
> > katzung1@comcast.net
> > www.astronomy-images.com
> >
> > ----- Original Message -----
> > From: "Chris Cook" <ccjd@ix.netcom.com>
> > To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
> > Sent: Wednesday, December 24, 2003 8:45 AM
> > Subject: Re: [APML] OT: digital vs film - fast comets
> >
> >
> > Hi Loke -
> >
> > How do you think the 300D would stack up against color films like 400F
or
> > E200 when used in the Schmidt?
> >
> > Chris
> >
> > ----------------------------------
> > Chris Cook
> > Astronomical & Nightscape Photography
> > www.abmedia.com/astro
> >
> > -----Original Message-----
> > From: Loke Tan <tan@cox.net>
> > To: Discussion of Film Astrophotography <astro-photo@seds.org>
> > Date: Wednesday, December 24, 2003 10:19 AM
> > Subject: RE: [APML] OT: digital vs film - fast comets
> >
> >
> > Chris,
> >
> > IMHO, I do not think that the Canon 300D nor the 10D single shot RGB
> > CCDs can equal a Schmidt with TP today. The Schmidt is very well
> > paired with
> > hypered TP in either B&W or tricolor. The combination is very optimal,
you
> > have the hypered TP film with extremely good resolution and reciprocity
> > characteristics, and you also have the very fast Schmidt which is
> > extremely
> > well corrected optically. The issue with the Canon digital cameras is
that
> > the lenses are not as well corrected to match the resolution of
> > the CCD. To
> > make better lenses, I am afraid the costs will be much higher.
> >
> > Loke
> >
> > -----Original Message-----
> > From: astro-photo-bounces@seds.org
> > [mailto:astro-photo-bounces@seds.org]On Behalf Of Chris Cook
> > Sent: Tuesday, December 23, 2003 11:35 AM
> > To: Discussion of Film Astrophotography
> > Subject: Re: [APML] OT: digital vs film - fast comets
> >
> >
> > Loke -
> > One thing I thought of concerning shooting fast bright comets(i.e.
> > Hyakutake etc...) is that the SBIG cameras will be unable to shoot a
color
> > image that does not have the stars broken up into Red, Green and Blue
> > trails. Not that this kind of image is bad, I just personally do not
like
> > them as well. The Canon 300D and 10D being single shot RGB chips can
most
> > likely equal the kind of comet shots done with film. As for wide field
> > digital, the Canon shooters will have to find a excellent 300mm f/2.8
lens
> > capable of being shot wide open with no aberrations of any kind ....any
> > ideas? Hopefully we'll find out this coming May...
> >
> > Chris
> >
> > ----------------------------------
> > Chris Cook
> > Astronomical & Nightscape Photography
> > www.abmedia.com/astro
> >
> > Another interesting thing which might happen is when the next
> > large/bright comet comes our way. I am curious to see if the best
> > widefield
> > images will be shot on CCD or on a Schmidt Camera with TP. The
interesting
> > matter here is that a large comet changes quite rapidly and the
> > f/1.5 speed
> > of the Schmidt really helps to shorten exposures for TP.
> > Unfortunately CCDs
> > will not be able to be used in a Schmidt unless you can curve the
> > chip. But
> > the CCD is more sensitive than hypered TP, so this will make a very
> > interesting comparison. Anyway, these are my current thoughts on the
> > subject.
> >
> > Loke
> >
> > -----Original Message-----
> > From: astro-photo-bounces@seds.org
> > [mailto:astro-photo-bounces@seds.org]On Behalf Of Tony Hallas
> > Sent: Monday, December 22, 2003 2:15 PM
> > To: Discussion of Film Astrophotography
> > Subject: Re: [APML] OT: digital vs film
> >
> >
> > Oh boy,
> >
> > Let's not start THIS again ... those of us who know
> > better know
> > that the boundaries between film and digital are starting to blur more
and
> > more with each passing day ... you may shoot film, but I bet you use
some
> > form of digital post processing ... where do you draw the line?
> > You can use
> > film to start with and use digital to process, or you can shoot
> > digital and
> > use dedicated film-type processing like Photoshop as the post
> > processing ...
> > the lines merge, black and white is turning gray ...
> >
> > The best thing that can be said for Rob's images is that he
> > aspires to make them as photorealistic as possible ... that's why
> > he should
> > stay on this list... I have seen CCD originated images that look
> > more "film
> > like" than some convoluted attempts starting with film and trying to
make
> > them look digital ...
> >
> > Those of us who come from a solid film background
> > and who have
> > been on this list for awhile have an edge on our "CCD only"
> > compatriots ...
> > ultimately the techniques that come to bear in making a great
> > photo must be
> > used even if the image had its beginnings as a CCD receptor ... speaking
> > from my own experience, about 20% of a CCD image that I make borrows
from
> > pure CCD technology ... the rest is all film.
> >
> > Tony
> >
> >
> > ------------------------------------------------------------------
> > ----------
> > ----
> >
> >
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> > >
> >
> >
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>
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