DSS Helps

If you are a Deep Sky Stacker user, here is a list of steps I compiled for a friend to help him navigate this program for success. Please know that this is just a list I made of steps that I use, not "the authoritative statement on the topic." So take it with a grain of cow salt.

Deep Sky Stacker Hints

a) Import the light, dark, and other files (if you have them) into Deep Sky Stacker. Be sure you use the appropriate menu choice for importing each type of file (lights, darks, etc.)

b) Select the "register checked pictures" tab on the left (I use XP Pro and that's where it is located).

c) Select the "Advanced tab in that dialog box. Choose a percentage that will yield between 35-80 stars found when running this tool. You will have to run the tool to see the results and make adjustments - the percentage will vary according to how many stars are detected in your frame and other factors.

d) Return to the other tab ("Actions") and select all three check boxes (Register already registered pics, Automatic detection of hot pixels, and Stack after registering).

e) Select the percentage of best pics you want DSS to stack. It will automatically cull the worst, or you can just select 100 percent for all to be used.

f) Click on the "Recommended Settings" tab, still in this same dialog window, below the other items. Choose the following:

1) Use bilinear debayering

2) Do NOT reset the white balance settings for a modded DSLR. It never works well for me... Leave the setting alone unless it needs to be changed to comply with my request.

3) Scroll down to the last choice, "If the color balance is hard to fix in post processing" and select it so that it reads "Use RGB background calibration." All the settings in this window (Recommended settings) can be changed elsewhere, so don't panic if they are not as I described.

g) Click okay to return to the "Actions" dialog window.

h) Click "Stacking Parameters" and choose the "result" tab. It is usually preselected anyway.

1) Be sure the intersection mode is selected and the "Align RGB channels in final image" box is checked. THIS IS IMPORTANT! Do not enable drizzle, it takes forever and eats memory. You may try it later if you wish.

2) Select the "Lights" tab from the menu across the top of the window. Check the "Median-Sigma Clipping" box. You can experiment with other choices later.

3) Select the "darks" tab and choose "median"

4) Under Alignment tab select "automatic."

5) Under intermediate files choose either FITS or TIFF. I prefer to use TIFF files so that I don't have to convert them when I open Photoshop. I hate the FITS converter and can never get satisfactory results from it (thanks NASA!).

6) Under Cosmetic tab choose detection for both hot and cold pixels at one pixel each. Adjust the percentage slider to 70 percent.

7) Under Output tab select "create output file." Also select "Autosave" and choose where to save it in the next section. I trust you can find the files after they are created! Then click okay to close this window and return to the Actions window.

Click okay and let DSS stack the image. Wait for it to finish and make NO adjustments to the result. When it is finished choose "Save picture to file" from the Processing menu along the left of the screen. The "Save As" dialog will come up. Choose where to save and what name, etc. Also choose the final output file type - FITS or TIFF and be sure they are the simple 16 bit files, not the integer stuff. I like the TIFF image (16 bit/channel). If you are using Elements, GIMP, or an earlier version of PS then choose the eight bit/channelTIFF. Yeah, you're losing lots of data instead of having a huge 32 bit file, but hey, this ain't the space shuttle! Besides, if you want to print you'll have to dumb it down to 8 bits anyway.

Choose no compression. Then HERE IS THE IMPORTANT PART!!! Choose embed adjustments but DO NOT APPLY THEM!!! This prevents the image from being stretched by DSS. Let other software do the stretching because it is better at it. DONE!

I am enclosing a low resolution stacked frame that has come straight out of DSS for your reference. Notice that it is really dark and shows little detail. This is how your stuff should look after DSS. Don't stretch anything until it gets into your post processing application (StarTools, Photoshop, Images Plus, etc.).

I hope this page will assist you in getting started using DSS. It is a bit intimidating at first, but read the help pages thoroughly and just gloss over the deep stuff. Have a good time!