tornado33
05-09-2009, 11:27 PM
Hi all
The other day I did some modifications to my 10 inch scope. I moved the primary mirror up the tube about an inch, to allow the Q guider camera to get focus without the 2.8x barlow. Id been having trouble finding bright enough guidestars for some objects with the off axis guider. Using a 2.8x barlow on comatic stars spreads them out too much, over too many pixels. However, going to 1x (no barlow) means (in theory)smaller more numerous available guidestars.
Anyway, to test it, I got out tonight even though moon was full. The Dumbell was the first test. Seeing ,looked awful, guidestar was boiling and shimmering, but I got best possible focus on both imaging and guide cameras and went for it. What I got came out far better than I expected with the seeing and also the VERY moonlit skies. I did use the UHCS filter.
Image is 9x10 mins ISO400. UHCS and UV/IR filters. MPCC coma corrector, Hutech modded 350D, 10 inch f5.6 newtonian, with off axis guider. Ive included a full res. crop
Ive included a shot of the 23 year old mount I used to take the image, after Id packed it away in the garage. It is lit by moonlight! Also a shot of the backyard.
I am amazed at technology today that allows DSO objects to be imaged under a full moon, yet with a scope and mount built 23 years ago, well before that technology existed.
Anyway using the guide cam at 1x seems way better then at 2.8x as the smaller sharper stars outweighs loss of magnification. The interface between the guide cam and the mount (me) was able to hold the guide star steady on the artificial reticle on the laptop.
Scott
The other day I did some modifications to my 10 inch scope. I moved the primary mirror up the tube about an inch, to allow the Q guider camera to get focus without the 2.8x barlow. Id been having trouble finding bright enough guidestars for some objects with the off axis guider. Using a 2.8x barlow on comatic stars spreads them out too much, over too many pixels. However, going to 1x (no barlow) means (in theory)smaller more numerous available guidestars.
Anyway, to test it, I got out tonight even though moon was full. The Dumbell was the first test. Seeing ,looked awful, guidestar was boiling and shimmering, but I got best possible focus on both imaging and guide cameras and went for it. What I got came out far better than I expected with the seeing and also the VERY moonlit skies. I did use the UHCS filter.
Image is 9x10 mins ISO400. UHCS and UV/IR filters. MPCC coma corrector, Hutech modded 350D, 10 inch f5.6 newtonian, with off axis guider. Ive included a full res. crop
Ive included a shot of the 23 year old mount I used to take the image, after Id packed it away in the garage. It is lit by moonlight! Also a shot of the backyard.
I am amazed at technology today that allows DSO objects to be imaged under a full moon, yet with a scope and mount built 23 years ago, well before that technology existed.
Anyway using the guide cam at 1x seems way better then at 2.8x as the smaller sharper stars outweighs loss of magnification. The interface between the guide cam and the mount (me) was able to hold the guide star steady on the artificial reticle on the laptop.
Scott