Re: [APML] Cats paw on the tail of the scorpion

["Stuart Heggie" <stuart.j.heggie@sympatico.ca>]

Len, this version looks a lot better. Colours are good. A 0.5 pixel radius, threshold of 1 at 80%
Unsharp Mask in Photoshop seemed to tighten up the stars nicely.

Stuart
----- Original Message -----
From: "ice" <ice@houston.rr.com>
To: "'Discussion of Film Astrophotography'" <astro-photo@seds.org>
Sent: Saturday, March 05, 2005 3:49 AM
Subject: RE: [APML] Cats paw on the tail of the scorpion


Thanks for the comments.

It was the noise removal step that affected it the most.  Here is another
version.  Not as aggressive on the noise.

http://home.houston.rr.com/lencasady/catspaw01.jpg

I think the shot was at F/3.3, which is wide open.

Len

-----Original Message-----
From: astro-photo-bounces@seds.org [mailto:astro-photo-bounces@seds.org] On
Behalf Of Ray Butler
Sent: Friday, March 04, 2005 11:00 AM
To: Discussion of Film Astrophotography
Subject: Re: [APML] Cats paw on the tail of the scorpion



Hi Len,

The colours look fine on my screen (set to 9300K colour temperature). No sign of
residual vignetting. Can't see any obvious trailing, but the image scale is
small in that
jpeg, so that helps to hide it.
It does look a bit soft. Hard to tell why, as some jpeg compressors can
have this effect too. Was it more apparent after your noise removal step? There
are clear bluish chromatic halos around stars - so I presume the
200mm lens was at full aperture; would that be f4?
Overall, a very nice result!

Ray

>With all the bad weather here in South Texas lately, the only thing to
>do is processing.  Of which I need lots of practice.  Thought I try
>fooling around with some of my not so well tracked or guided shots.
>
>I shot this two years ago at TSP.  This was my first shot with a lens
>>50mm.  I was excited when I first looked at the scan at the lab
>without a loupe.  But, when I got home the scan showed some trailing.
>I think it was guiding and not field rotation as the elongation of the
>stars appeared East-West and linear on the top and bottom of the frame.
>
>Just a few details as I would have to find the old logbook... OM1,
>200mm, E200, piggybacked on an LX200 w/ wedge.
>
>http://home.houston.rr.com/lencasady/catspaw.jpg
>
>There was also some very obvious vingetting and noise I tried to
>remove.  Does it look way too soft?
>
>How are the colors?  On this note, I found that my colors looked
>different at home than they did when viewing from work.  Found that the
>Nvidia video driver had a setting for "Digital Vibrance" turned on.  I
>think it basically ups the saturation and brightness of the screen.
>Turned it off and then processed.
>
>Comments?
>
>Thanks
>Len
>
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