Posts Made By: Larry Durst

I'll say you've learned a thing or two! (Would love to see the original for comparison's sake.)
Nice image,
Larry

Talk about leapin' off the monitor! Stunning.
Larry

Wind, wind, wind, CALM, wind, wind, wind...
I, too, am just getting a start on autoguiding. Your experience should certainly help...whenever the wind dies down. Thanks for the update,
Larry

Greg,
I'm not exactly the most experienced person in the group, but since I, too, spent way too much time figuring a filing and naming system I thought I'd share mine. I don't use CCDSoft, but rather AstroArt3. But I'm sure this will apply. Also, the best tool I have found for logging is a good old fashioned spiral notebook.
Here goes:
For each sequence I shoot I label the file with some simple, quick to identify information. If I were shooting M51 tonight, here is what a file might read: M51a_L_20060404_
That's M51, the "a" is for the first sequence (then b, c, etc.), L is for Luminance and then the date. The final underscore will be followed by a file number for each shot automatically supplied by AA3 in autosave mode. These all get saved to my hard drive. The next morning I will put into a folder, then subfolder for L, R, G, B, darks and flats I've shot that night. I then create an entire duplicate folder called M51_20060404_Workfolder. I use that folder for all my post processing, storing away the original for safe keeping. In Excel, using the Object name in one field and the date as YearMonthDate in another lets me call up the data either as an alphabetized object list or as a date order list. I find this very useful
As I said earlier, I also keep a written journal of all my photo and observing sessions. In this I'll record temp. conditions, angle of scope, location of object in sky, time, etc., along with number of integrations, time of exposures, etc. I write this on one line per sequence forming a column in the notebook. This is all transferred to an Excel chart the next day (when I'm not lazy). I keep a separate Excel chart for myh finished images with a naming system (eg: M51-001_LRGB_100+20+20+20_Date). On the second processed images chart I'll note the file name of the original raw images. On that first chart I'll also now list the finished image number.
I know this all sounds complicated, but I have been able to go back and find anything this way, and not have overly long and complicated file names. I have all my original raw images backed up to numbered CDs which I also note on the Excel chart of raw images.
As far as postprocessed file naming, I just keep adding steps to the name as I "save as" each step, eg: M51_DATEOFCAPTURE_30x30x_AvgcombineAA3_DDPAA3_HighPassAA3_CurvesPS_croppedAA3 etc. I'll then log all of that information on my processed image chart and finally rename the file more simply as stated above, eg: M51-001_LRGB_30+10+10+10_date.
Sorry for this rather long-winded reply, but I do hope a bit of all this might help.
Regards,
Larry

Greg,
Congratulations!
Larry

Wonderful!
Larry

Eric,
Very nice shot. I'd be quite interested in hearing your impressions of the mount--I'm beginning to eye one myself. I would be using a separate autoguider and guide scope.
Thanks,
Larry

Dennis,
Just spectacular. Really amazing detail and depth. I'm beginning to focus on galaxy clusters myself (really enjoy wide field imaging, for me it's quite forgiving!) and your shot gives me something to try and attain (I did say "try" . As for image size, I do like this size, but perhaps a smaller version attached to the Astromart message with the link to your site might be good for convenience.
Again, great image.
Larry

Alex,
Not only a nice change of pace for this group, but an exceptional image on its own right. I hope this getting framed for your wall.
Larry

Mark,
There are really two answers to this that I know of. One I have experience with, the other will hopefully be answered by someone with greater experience.
1) Depending upon the angle of the object in the sky which you are shooting, each color filter will allow different amounts of light to get through. Straight up, all is pretty equal. But the lower in the sky you go, you begin to lose more blue than red to due to the increasing amount of atmosphere the photons pass through. Different wavelenghts get absorbed in different amounts. More atmosphere the greater the ratio between the colors. This is probably why you lean toward more red or, thought of differently, less blue. There are atmosperhic extinction charts that allow you to compensate for this--I use one by a terrific imager named Jon Talbot which I don't have here at work but can direct you to at once I'm home. (I got it posted on the Yahoo Starlight Xpress group.) This chart includes multipliers that enable you to compensate each color due to the loss at the angle you shot. The processing software I use, AstroArt3, lets me due this in post processing.
2) I understand that any manufacturer's set of filters will also have unique characteristics between the colors that can be measured and then compensated for, again in processing or in the duration you shoot each filter. I personally have never done this. I shoot all filters equally then use the process described above.
I hope this makes some kind of sense. I would highly recommend reading "The Handbook of Astronomical Image Processing" by Berry and Burrell to really get a handle on this, and pretty much all other topics relating to post processing. (Also comes with an excellent processing program, as well.)
One other thought--you can actually go less on the colors than on the luminance since all of your detail is in the lum. In fact, go as long as you possibly can for the luminance--a ratio I've seen that I tend to use is RGB added up to equal the lum. So a good ratio would be one hour than twenty minutes on each color, for example.
Again, hopefully someone with even more experience than myself will chime in here as well.
Regards,
Larry