From: Milton Aupperle <milton@outcastsoft.com>

Date: September 6, 2005 4:29:11 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Old Aristarchus VS Stretched Aristarchus Comparion


Hi Alan;


On 6-Sep-05, at 3:50 PM, Alan Friedman wrote:

Hi Milton -


Nice comparison of two processing values. Overall I prefer the first rather than the stretched due to the artifacts introduced in the dark regions in the stretched version (perhaps from the sharpening). 


The black edges are from the compositing, as their is no image along the left bottom side for 2 of the joined images and that's auto filled in as "real black". The "dithering" pattern is quite obvious on the laptop, but not visible on the desktop (both CRT and LCD) Macs.


It all depends on how your Mac Monitor / LCD is calibrated. On my Desktop G5 and G4's (calibrated more towards PC's than Macs for video and for other stuff I'm moving into), you can just barely see the black boundary or the dithering noise, but on the PowerBooks it's very obvious.


And the 1.25 gighz PowerBook tends to "forget" what i have it calibrated too a a lot (like every re-start) and you have to reset it (another OSX 10.4.2 "feature" from Steve Jobs - like crashing the doc consistently and repeatably  when attaching a TV as a second monitor).


Had I done the processing on the PowerBook, viewing it on the desktop would look much darker than it actually is.



I've uploaded a couple of new images to the files area - an aristarchus regions at similar focal length to Milton's but at a different sun angle, an image of the crater moretus and southern highlands region at 7.5 meter focal length, and (in the DSO folder) a just completed webcam image of M57 taken this past weekend at the Black Forest Star Party. I've always wanted to try a deep sky target with my webcam and AstroIIDC - this one came out better than I thought it would.


Nice images. The M57 one turned out really good considering the longest exposure you can do with the DMK21BF04 is 30 seconds and it's 8 bit.


TTYL..


Milton J. Aupperle

President

ASC - Aupperle Services and Contracting

Mac Software (Drivers, Components and Application) Specialist

#1005 - 815 14th Avenue. S.W.

Calgary Alberta Canada T2R0N5

1-(403)-229-9456

milton@outcastsoft.com

www.outcastsoft.com