Deep Sky Capturing & Processing Procedure

1) Align the scope

2) Set up the camera

Before attaching the camera, I remove the visual back of the scope and attach a 3.3 focal reducer. Then I replace the visual back and insert the camera (which has a 1 1/4" barrel) in place of an eyepiece. I attach the camera to a Toshiba security monitor, and then I attach the monitor to my camcorder. NOTE: For wide-angle shots, I use an Orion ST-80 refractor. Therefore, the visual back / focal reducer step is not applicable.

3) Re-align

The two-star alignment is fine for visual work. It will easily put objects within the FOV of a 9mm eyepiece. However, the tiny CCD chip in the camera can only "see" a tiny amount of the FOV. For this reason I need a higher precision alignment. Fortunately the Meade Autostar has such a function built in. Here's how I use it for CCD video imaging: I GOTO a bright star in (or near) the constellation in which I will be imaging. Rarely does this star end up in the FOV of the CCD chip. I center the star on the chip using a combination of my Telrad finder, and the video monitor into which the camera is sending its signal. Once the star is centered in the monitor, I re-focus. Refocusing is necessary because the focal length has changed with the addition of the focal reducer and the distance of the camera. All I do next is activate the Autostar's sync function. I now have higher precision GOTOs and tracking for that particular area of the sky.

4) Start imaging

I GOTO my first target and press Record on the camcorder. I have the camera set to take 8.5 second exposures. This is the maximum exposure time for the StellaCam II. I usually record around 12 images that I will later align, stack and process. Ideally I would like to take many more images for stacking, but any more than around 10-12, and I get field rotation (This is the down side of not using a polar aligned mount). [UPDATE - I recently started using AstroArt software to align and stack my images. AstroArt can compensate for field rotation. Therefore I am able to take many more images for stacking than I was able to in the past.] I simply repeat this process for each object I want to image. NOTE: If I want to image an object more than 25 degrees or so away from my original object, I GOTO a bright star in the constellation containing the new object and re-sync for that area of the sky.

5) Process the images

I use a FireWire capture card (and software) to get the still images from the camcorder to my computer. Once I have all 10 (or however many) of a particular image, I align & stack them using AstroArt. I then save the resulting file as a BMP and open it up in Photoshop Elements where I adjust levels and contrast.

Note about DV Video

For Planetary imaging, instead of capturing a few long-exposure pictures, the method is to capture several hundred short-exposure pictures. This is done by capturing in a more conventional "video" mode, and then stacking each frame of the video to produce a better image.

When I first began doing this I became very frustrated because I was not able to open my DV video clips in any of the programs used for separating and stacking the individual frames. That is, until Howard Anderson came to the rescue. He has a program called HandyAvi. I open my DV video clips in this program and then re-save them. The result is a standard AVI file that can be read by any of the stacking programs. Howard's program also allows you to crop the frames, and save only selected frames if you choose to. What a life saver - Thank you Howard.