Here's what I got when I combined the images after applying the dark and flats and fixing the two bad columns (grrrr), removing the hot pixels, removing the cold pixels and aligning all four images: http://users.wirelessbeehive.com/~paw/temp/MI_2008_JAN_08.01.JPG Like I said, not Tyler like. 3,900 mm is too long a focal length for needle-sharp stars and 5 minutes is too little exposure to get a lot of color and get rid of the mottled appearance. Remember that the 4 originals were all 1 minute exposures. As I'm pretty sure Tyler will confirm in the real world (not this lab exercise) the amount of exposure for each of the clear, green, blue and red light images varies depending on the object being imaged (I'm not sure but I don't think that can not be done with the 1 shot cameras). Several folks have asked for my kit. I look forward to seeing how their results look. Maybe next clear night I may shoot several one minute exposures of each color and make them available. That way folks can use the same flats and dark and vary the exposure of each color (depending on how many of each color they choose to use). Carpe Noctem! patrick On 08 Jan 2009, at 18:29, Patrick Wiggins wrote:
I spent some time collimating my scope last night after which I took a few test shots of M-1 which just happened to be transiting.
Knowing there are some folks here on the list getting into astroimaging I made images for a "kit" that could help folks get a feel for what's involved in making color images.
The kit contains:
1-Raw exposure with clear filter 1-Raw exposure with green filter 1-Raw exposure with blue filter 1-Raw exposure with red filter 1-Master dark to be used to reduce all of the raw images 1-Master clear flat for reducing the raw clear 1-Master green flat for reducing the raw green 1-Master blue flat for reducing the raw blue 1-Master red flat for reducing the raw red
The master dark was made by shooting and median combining 15 darks.
The master flats were made by shooting and median combining 15 each flats shot through the clear, green, blue and red filters.
I should note that using the kit will not get you "Tyler like" images. Though the final image should look pretty good the main purpose of the kit is to show folks what's involved in making "real" color images (I say "real" as opposed to the one-shot cameras which, like color film, sometimes produce questionable colors).
Let me know if you'd like a kit and I'll email it out.
Clear skies!
patrick