Having owned and used a C-11 HD for three years now, I can attest that the white paper is honest and accurate in all aspects. For a more detailed review see pg 69 in the Jan-Feb 2012 issue of Astronomy Technology Today (www.astronomytechnologytoday.com). I have previously owned and imaged with several older Celestron SCTs, including a classic 10, and more modern C-11 and C-14. The HD version is significantly better in all respects, both visually and for imaging. Better contrast, very flat field, no coma. Visually it's more like an 11-inch apo refractor, totally color free, with pin point stars across the fov. For imaging there is no comparison. A focal reducer, either from Celestron (0.7 X) or Optec Lepus 0.62 x) is essential for imaging wider fields, etc. The passive vents and mirror locks also work very well, although mirror flop is not totally eliminated. All in all a fine instrument. Klaus -----Original Message----- >From: "David M. Douglass" <dmdouglass@xxxxxxxxxxxxxxx> >Sent: Dec 3, 2012 5:43 PM >To: az-observing@xxxxxxxxxxxxx >Subject: [AZ-Observing] Celestron White Paper on their HD Technology - a Good >Read > >Well, I can't forward the actual email from Celestron, but I can post the >link to their White Paper... > >http://www.celestron.com/portal/technologies/edgehd-optics/&utm_source=Celes >tronblast&utm_medium=Email&utm_campaign=EdgeHD/ > >Not an endorsement. I don't own one, and probably won't (in the near >future)... >But I am curious about their technology, and I like to learn. >I found it a "good read".... > >David M. Douglass >dmdouglass@xxxxxxxxxxxxxxx (secondary) >david@xxxxxxxxxxxxxxx (main) >Cell (602) 908-9092 > > >-- >See message header for info on list archives or unsubscribing, and please >send personal replies to the author, not the list. > -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.