Monday, 1 September 2014 | Tim
I used this telescope on an HEQ5 mount with Celestron X-Cel LX eyepieces and a Teleview 2x Barlow.
Most opinions on a telescope of these specifications tend to grumble about chromatic aberration and its rather large size. Although this telescope is large, a good motorized mount like the HEQ5 made it easy to use. Chromatic aberration was present on bright objects such as Vega, however, it was completely absent on dimmer objects. I really didn't find CA an issue when using this telescope.
I have not had the chance to view planets or the moon but I did have a lot of fun observing some DSOs. I observe from a very light polluted site (a sodium street light casts a shadow of me on the ground), but I was able to get some of the best views of open clusters that I have personally seen. The rich orange colour of Albireo contrasted with the blue of its partner and I got great views of Ring and Dumbbell planetary nebulas. I'm really looking forward to using this scope in the years ahead.
It has to be said that a huge refractor looks really cool too.
Sunday, 29 May 2011 | Andrew
I owned the older, blue-tubed version with collimatable lens cell and rack and pinion focuser. I imagine my comments will equally apply the latest version. Regarding the differences, in my experience, refractors keep collimation very well, so the lack of collimation shouldn't be a problem, and a crayford focuser in the latest version is very welcome addition indeed. The rack and pinion focuser on my one left something to be desired...
Optically, I found this a fantastic instrument which controls CA well. Of course, being achromatic, there is some blue fringing if you push the magnification on high-contrast objects. It does not take too much from the view, and can be filtered out if you feel the need.
One thing to be very aware of before you buy is that it is a very substantial telescope - long, heavy and cumbersome. It will certainly need a heavy duty mount - an EQ5 very minimum, and a tall tripod.