Last updated: 23 May 2002

This page documents image processing software comments, tips, and photos. Contributions welcome.

Jump to the Start of Today's Update (please wait for the page to finish loading).

Subject:	Unsharpe mask
Sent:	Thursday, September 6, 2001 3:43:35
From: (Marius van Leeuwen)
I think it is nice to see what Adobe Photoshop unsharp mask can do with
a shot of the moon. I send you 3 pictures taken with my etx 90 and sony
digital camera. on May 30 2001.

The first is the original, number 2, I give more contrast put it in
grayscale and give it an unsharpe mask ( you have to try the different
handels in that filter for the best results) and number 3 is a closeup
also with unsharpe mask.

Don't place the shots to smal so you can see the differents

Kind Regards
Marius van Leeuwen The Netherlands 

Click on each image to see the full size version.

Moon Moon Moon

Subject:	Stacking Photographs
Sent:	Tuesday, December 18, 2001 12:16:09
From: (Brian Gaines)
I have adobe photo shop 6.0, I was wondering how do u combine pictures?
u know people say they have stacked photographs how do u do that with
adobe photo shop 6.0?
Mike here: Windows users use a program called AstroStack, a pretty nice piece of software. Stacking in Photoshop is more a challenge as you have to align the images and play with the various parameters. I've never gotten good results with it. Hopefully someone else will help with this one.


When stacking photos can u only use a video camera.   Or can I use my
Nikon coolpix
Mike here: Since stacking works with individual frames, you can use the frames from a video camera or multiple images from a still camera.
Subject:	exposure
Sent:	Wednesday, December 26, 2001 11:02:12
In the Guest Astrophotography Gallery - Deep Sky, there is a photo
of M42 ( (chan sing) [25 Dec 01]) with this

"Attach photo was used selfmade 70mm refractor(disassembly from
binocular)+40mm eyepiece.mount on ETX90EC,polar tracking.used casio
QV-3500 digital camera,ISO 300,exposure 60sec.3X zoom.used astrostack
and photoshop edit.6 frame stack."

Does that mean it consists of a total of 5 hours of exposure or total it
equals 60 sec? how can the pictuer be so bright from a 70mm telescope
Mike here: You should direct your exposure question to the submitter of the photo but I presume he "stacked" six 1 minute exposures. The nice thing about CCD imagers (even those in today's digital cameras) is that they can build up images rather quickly. And stacking adds them to increase brightness and bring out details.


i didnt know he used a cdd imager he said he used a cassio or
something...or do all of todays digital cameras have cdd images...i have
a nicon cool pix 995...does that have a ccd imager?
Mike here: All digital cameras use a form of CCD.
Subject:	AstroStack
Sent:	Wednesday, December 26, 2001 11:40:08
From: (Brian Gaines)
Did u ever figure out y i can only stack two pictures at a time in
astrostack? Because I cant figure it out.
Mike here: Sorry, I don't use Astrostack. Have you contacted the developer?
Subject:	AstroStack
Sent:	Wednesday, December 26, 2001 11:41:26
From: (Brian Gaines)
When i try to increase the amount of input pictures it goes to ZERO! ANY
Mike here: Sorry, I don't use Astrostack. Have you contacted the developer?
Subject:	Stacking on a MAC
Sent:	Saturday, December 29, 2001 0:18:39
From: (Brian Gladstone)
I've been an observer of your site for about 6 months now--you do a
wonderful job and it is a true service that you provide to us novice
astronomers.  I was convinced that I should buy the ETX-125EC because of
the rave reviews I read here and in amateur astronomy magazines, and was
fortunate enough to hit a store that was going out of business so I only
paid $400 US.  After seeing Mars in all of its glory, I am now focusing
on Jupiter and Saturn.  I recently puchased an Olympus 3030Z and want to
start doing astrophotography.  I have tons of pictures, but I would like
to clean them up--do you know of any "stacking" programs like astrostack
for the MAC?  Thank you for your advice.


Brian Gladstone  
Mike here: I wish I did know of an Astrostack for the Mac (Classic or OS X). Doing it in Photoshop is too painful. If you have VirtualPC you could run Astrostack but I've not done that since I find using Windows even more painful.


Thank you for the quick response and advice!  I'll tell you if I find
something--I'm sure that someone has developed a similar program for the
Mac.  I will send you some of my photos shortly.  It is pretty
impressive what one can do with the ETX.

Mike here: From MacInTouch ( "The National Optical Astronomy Observatories has announced plans to release IRAF 2.12 for Mac OS X. The Image Reduction and Analysis Facility is a software suite for processing astronomical images."

Start of today's update

Subject:	stacker for Macs
Sent:	Wednesday, May 22, 2002 21:23:18
From: (William L. Schart)
I saw the recent post to your site by one Brian Gaines about stacking.
From your reply, apparently you are jot aware that there is an image
stacking available for Macs:

I have done a little with it, seems to work fine. It is a "classic" app,
but runs fine in Classic in X.

William Schart
Mike here: I am aware of it (it is on the Astronomy Links page) but I have yet to try it myself.

Return to the top of this page.

Go back to the Astrophotography Page.

Go back to my ETX Home Page.

Copyright ©2001-2 Michael L. Weasner /
Submittal Copyright © 2001-2 by the Submitter