click on image for full size
Tonight I took my first set of DSO images using the Nikon D40 with my LX200. Sky conditions were excellent, with seeing at 4/5 and transparency at 4/5 as well. I headed up to the local observing spot with a good mate of mine who had one of his many refractors (provided excellent views of a Jovian transit as I packed up).
I targeted M13 initially, as this is a very bright globular cluster and made for a somewhat easy target. Despite some galah incorrectly wiring his telescope nearby causing it to goto objects in the Southern Hemisphere, I was able to focus on the task at hand and managed to take lots of snaps :-)
This image is my best for tonight.
10 * 20 second exposures
Processed in Deep Sky Stacker
Mild curve adjustment and sharpening in Photoshop
A few folks have messaged me asking for the method used. So, here it is. I am far from an excellent astrophotographer as I am just starting out, so take this with a pinch of salt!
- Align the scope using 2-star alignment method in Alt-Az configuration.
- Set camera settings:
- Put camera in full manual mode (“M”) on the mode dial
- Press the + Magnifying glass button twice to modify settings, using the arrow cursor key button to navigate to each setting
- ISO 1600
- Shooting mode to remote control, zero second delay
- Quality to HIGH JPEG (this is what I used last night, but I think you’d be better using RAW mode)
- Noise Reduction ON (Next time I want to try without noise reduction, I think this actually causing more noise)
- Set shutter speed (using click dial on back of camera) to 20” (20 seconds)
- Place camera on scope
- Camera attached to T-Ring, then 2” T-adapter for use with my 2” diagonal
- Command the scope to GOTO a nearby BRIGHT star to use for focusing
- View the star in the image finder of the camera, use focuser on scope to get sharp image
- Then go to desired object (for example, M13)
- Check viewfinder again to see if you can see object
- Take a sample shot
- Review the sample photo
- Try and center it in the field of view. This may be an iterative process
- Focus focus focus! This is hard and takes practices, again iterative
- When satisfied, take a sequence of shots
- I took ten shots for each object
- When done, process all images in a stacking software program
- Last night I discovered Deep Sky Stacker (DSS). It is freeware and very easy to use.
- Normally I use Registax (also free) but for some reason DSS gave me much better results.
- Then sharpen and adjust in an art software program like Photoshop
- Apply mild sharpening, not too much as it brings out noise
- Curve adjustment can be good, brings out subtle colors
- I also use freeware noise reduction software like Imagonic Noiseware to try to reduce extra noise in the image.