Re: Re:[APML] orion mosaic

["Robert Gendler" <robgendler@worldnet.att.net>]

I see from Wei-Hao's color separate color channels which
he posted on his wweb site that the h-alpha is actually well
recorded but he decided on a less aggressive approach in
the final processing towards a more "natural" look.

Not taking anything away from this beautiful mosaic one must
understand it was taken from some of the most pristine skies
on the planet at high altitude. A result like this is beyond what
almost any of us can achieve using traditional techniques given
our sky conditions.

That said it is possible using narrow band color composite tecniques
to achieve a similar result even from a very mediocre location. See:
http://www.robgendlerastropics.com/Orionhunter.html

I think we should all appreciate Wei-Hao's beautiful result but without
denigrating what others have tried to do under far less favorable
circumstances.


Rob Gendler
email: robgendler@att.net
Web Site: http://www.robgendlerastropics.com
----- Original Message ----- 
From: "Philip Perkins" <ppastro2@astrocruise.com>
To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
Sent: Thursday, March 31, 2005 7:10 PM
Subject: Re: Re:[APML] orion mosaic


> Rob and Wei-Hao,
>
> I agree this is a wonderful wide field composition.  I think there is a
lot
> to be said for recording objects in the night sky as the human eye might
> see them if it were thousands of times more sensitive.  For this purpose
it
> seems to me that recording an unfiltered image on natural daylight film is
> very acceptable.  In this context use of an Ha filter is probably somewhat
> artificial - after all the human eye does not have an Ha filter stuck in
> front of it.
>
> The use of an Ha filter is the latest in a long line of CCD imaging
> fashions.  Remember that a few years ago an image had to be deconvolved to
> virtual oblivion before it was considered processed properly.  Nowadays
> little or no deconvolution is the norm.  The next vogue was intense star
> colours.  After this came galaxy images pock-marked with intense Ha
regions
> that look like a severe case of acne.  We all know that galaxies would
> never look like this naturally if we could be a few million light years
> closer.  Now an Ha filter has to be used if nebulous regions are to be
> considered recorded properly.  This will surely be replaced by some new
> vogue in the future.  Possibly new filtering techniques - I see that OIII
> filters are starting to be used more and more.
>
> These are all admirable methods in trying to achieve something different
> from static celestial objects where, unlike terrestrial objects, the
> lighting and aspect can never change.  But, broadening the mind a little,
I
> think there is actually a wide spectrum of other techniques that can show
> different aspects of the night sky.  Although tried and trusted, the
purity
> of an unfiltered image on natural daylight film has a certain appeal for
> me, of which this image is a classic example.  The Ha regions seem to be
> very well recorded - besides, Ha is only one aspect - there is a lot else
> going on in this image which notch-filtering of Ha wouldn't help,
including
> the Witch Head nebula.
>
> --Philip
>
> At 06:03 31/03/2005 -0500, you wrote:
> >Hi Wei-Hao,
> >A beautiful rendition of this region. I like the stars and in particular
the
> >nice compact starfield in the upper left....I haven't seent this before.
> >One comment though is the weakness of the h-alpha emission even from
> >a dark sky like yours. Really only narrowband h-alpha imaging can bring
> >the faint emission out.
> >Rob Gendler
> >email: robgendler@att.net
> >Web Site: http://www.robgendlerastropics.com
>
>
> Philip Perkins
> <ppastro2@astrocruise.com>
> Wiltshire UK & Luberon France
> www.astrocruise.com
>
>
> _______________________________________________
> Astro-Photo mailing list
> Astro-Photo@seds.org
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