Re: [APML] c2001 q4 NEAT and M44

[belatrix <belatrix@ozemail.com.au>]

Rodney
Sounds like you got all the right gear, an f1.2 55mm lens - didnt know
lenses got that fast! We also always do the, very old trick, of stopping
down our lenses at least one stop and always will, definitely an easy way to
improve shots.
 
What I know about the subject of astro-photography and processing is
extremely basic and limited, and would fit on the head of pin. But I can
only tell you what i know, from what i have so far.
(there are two year full time courses on scanning and related things, i have
heard of!! had a friend work for Xerox and said you would become a professor
in scanning by the time you learnt everything about the subject )
 When i scan comet shots, 99% of the time, I am using 6x4 glossy prints from
a photo-processing outlet (we have always used Fuji NPZ/CZ 800 film on
comets and most stuff) When i scan comet shots at 1200 dpi I use twain
acquire in PS 7, and in the past PS 6, i usually get a close to 100MB file
to work with. When i work in layers to 1. colour balance/2. levels/3. and
very mild, unsharp mask, i can end up with three layers in addition to the
original file before the final flattening, megs can get up to 400 MB + after
doing the 'works'. Of course this is for whole 6x4" photo, if it is cropped
down to remove field rotation or some other horror, or close in, whatever,
it is going to be  smaller file. But I have noticed a big difference in
quality when i have a couple of times, scanned larger prints at 1200dpi, of
course they are ridiculous sized files to work with, but i can get much
better results if I wanted too.
I only scan comet shots and other guided deep sky shots at that resolution,
most things i do at 300dpi and do no enhancement, just the normal final
'save for the web', and maybe a crop, or hair nebula removal beforehand.

Cheers and keep em coming mate.
Kearn
> From: "Rodney Watters" <ryderhome@bigpond.com>
> Organization: Ryder Homestead
> Reply-To: Rodney Watters <ryderhome@bigpond.com>, Discussion of Film
> Astrophotography <astro-photo@seds.org>
> Date: Wed, 23 Jun 2004 22:03:06 +1000
> To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
> Subject: Re: [APML] c2001 q4 NEAT and M44
> 
> Kearn,
> 
> Thanks for the feedback. I am pleased to be able to exchange ideas with
> other Aussies.
> 
> Specs for photo are:
> Canon F1; 55mm F1.2 lens @ 4.0 (too much coma and vignetting if I don't step
> down the lens). Exposure = 10 minutes. Manual guiding on comet core.
> Losmandy GM8 mount.
> Scanned on my recently purchased Minolta Dimage Scan Dual III. This scanner
> has a scanning resolution of 2820 dpi and a quoted dynamic range of 4.8. I
> did not do any adjustments at the pre scan stage but simply scanned the
> slide at full resolution. The Minolta driver allows one to specify the
> output image size which I set to 5x the physical 35mm positive. Resultant
> tiff file size was 28.1Mbytes.
> Processing in photo shop by simply using auto levels and then adjusting the
> brightness and contrast. Image was then resized and saved as jpeg for web.
> 
> The purchase of the scanner ($800 AUD) was the best decision I've made as it
> gives me a chance to start sharing my work and obtaining critical feedback
> so that I can start improving my output. By way of example it is clear from
> the feedback I am receiving that I am being too aggressive with processing
> the images and need to spend more time looking at the subtleties of image
> processing and scanning. I guess I sort of knew this but I was keen to get
> some images out there anyway after flirting with this hobby for a while.
> 
> Rodney Watters
> 
> ----- Original Message -----
> From: "belatrix" <belatrix@ozemail.com.au>
> To: "APML" <astro-photo@seds.org>
> Sent: Wednesday, June 23, 2004 1:43 PM
> Subject: Re: [APML] c2001 q4 NEAT and M44
> 
> 
>

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