Tuesday 17 February 2015

AR12282 CaK Closeup 17th February

To say I am pleased with the Skywatcher ED80 I recently bought is an understatement. It excels on all levels in both CaK and Ha light, i've not tried it in whitelight, but, I have every confidence with it.  One of the reasons I got it was so that when I stopped it down to 60mm it would be operating at f10 and making a perfect complement for my CaK filter,  it also fills a gap between my 40mm and 80mm CaK setups, and I was optimistic I would be able to use it on a fairly regular basis.  Well everytime I have used it the scope has surprised me in a positive way, and today is no different.  I have been experimenting this half term with the use of extension tubes to amplify the power of barlows, and the combination I used for this image gave me an effective focal length of 1500mm, which, for 60mm aperture and the DMk31 is pretty much spot on for Nyquists limit in terms of image sampling.  Certainly the image is dripping with detail, and shows when used correctly what small apertures can achieve.