A few nights ago I was experimenting with polar alignment with my newly purchased copy of Alignmaster after I made some adjustments to my C6 SGT scope to minimize poor backlash. Alignmaster is best used in conjunction with a webcam for accurate alignment, although it can be done visually if no webcam is available. Anyway, after playing around with this and finding that I had greatly reduced the amount of backlash, this in turn gave much better polar alignment.
For a while I have been meaning to use my Canon EOS 600D DSLR to get a shot of Messier 13, the cluster in the constellation of Hercules, but since I had my LX-modified SPC900NC webcam already hooked up to the scope, I thought I would slew to M13, and see what kind of image I could get using the webcam before replacing it with the DSLR camera.
The resulting shot is a stack of 10 x 30 second lights (unguided) taken using K3CCD software with the webcam set to Long Exposure mode, and 5×30sec darks stacked and subtracted. Aligning and stacking was performed in K3CCD, and the final BMP image was saved at which point I tried Photoshop to process it.
I wasn’t happy with the sharpening in Photoshop, so I started again with the BMP and this time post-processed using Nebulosity 3 to apply levels/curves, adjust background colour, sharpening with unsharp filter, plus Star Tightening filter and GREYCstoration noise reduction. I also attempted using DDP as an alternative to levels/curves, but this looked messy and over-processed. I much preferred the more natural look without DDP, although for some images DDP can work wonders.
After taking the webcam images I went indoors to get the DSLR, but by the time I had removed the webcam, then connected the DSLR with T-adapter to the scope, plugged the USB lead to the laptop and fired up BackyardEOS, I looked up again and found that a light cloud covering had rolled in - those pesky sneakin’ clouds! So the comparison shot with the DSLR will have to wait until another night.