James Paulson's roll off roof observatory at the Sunridge Observatory site, taken in the summer of 1986, housing a 10 inch f/5 Cave Astrola Newtonian reflector telescope

Saturday, November 28, 2009

Progress So Far

I am pleased to report that digital astrophotography is not the bear that many people have lead me to believe. Like conventional film astrophotography, there will be disappointments, but the basics are pretty similar. Don't let the disappointments get you down, they are necessary for learning.

The following is a pretty basic guideline for how I image with my Canon XS DSLR.

1. Use a high ISO setting, at least in the beginning, like 800 or 1600. Aim your camera at the target. Make sure the camera is set in RAW + JPEG mode. I use a timer to control mine but you can use a laptop. I prefer the timer.
2. Use a good lens (the kit lens in my case), make sure your focus is good. Focusing is perhaps the hardest part of the whole operation.
3. Expose for a few minutes (I use 3 now) on a stable vibration free platform. You can shoot several exposures of the same length (and should). The more the better.
4. Your stable platform should be a good quality and well aligned mount, in my case, the LXD75 with the SN6 on it, camera riding on a bracket on the back. Your image is as good as your ability to keep it stable and tracking properly for the exposure duration. I view my object directly in my scope to check tracking.
4. Shoot a number of exposures on targets of the same length, use 2 or 3 minutes as a good starter. Cover the lens or whatever the camera is hooked to and shoot an equal number of dark frames of equal time which are used for subtracting the thermal noise from the images using software. Do this when you are done imaging what you want.
5. Load all the frames of your target object (lights and darks)in Deep Sky Stacker, stack them. DSS is a simple software package to use. Use the default settings, dig into the manual and online information for more help.
5. Take the final image and adjust it to your liking. I've recently began using PhotoShop and it makes it very simple to achieve pleasing results. PhotoShop is a world of its own, but it's basics have really helped me a lot.

This simple process will yield satisfying results, or at least it has for me.

About 4 weeks into this process, I am getting decent enough results to use as a basis for the hard part, which is working to achieve exceptional results. This is where it gets into precise polar alignment, much longer exposures, many more frames, learning how to use autoguiding, and learning a whole lot about post-processing. Start simple so you are not compounding your mistakes and wasting a lot of time making them.

I am amazed that I have gotten this far, and if I can do it, you can as well.

1 comment:

  1. Sounds like you are hooked. Congratulations! Nice work on M31 and M45. Hope you'll post more!