View Full Version here: : Celestron Edge HD scopes
gregbradley
15-04-2010, 06:22 PM
Anyone know anymore about these scopes?
They seem to be a nice improvement.
The 44mm would not handle a 16803 camera but it would handle
a 11002 chip camera.
Greg.
multiweb
15-04-2010, 06:27 PM
I hear they're the same optics as the older range. The only difference being a doublet placed inside the baffle tube at the primary plane level to correct the imaging circle. Both mirrors are apparently still spherical. Meade went the other way by adding an hyperbolic secondary in their ACF range.
gregbradley
15-04-2010, 08:11 PM
I was wondering if that is what they did. It appears from their video that that is what they have done. Its a bit unclear if they changed their optics. They use big words to cover this up.
Mind you that may be a good approach as the current optics are easier to make.
Greg.
DavidTrap
15-04-2010, 10:44 PM
There are some comparisons made on Cloudynights. I think some who had looked through both thought the Celestron were better - can't recall if their testing was conducted with anything more "scientific" than a "calibrated eyeball" though.
The Meade ACF is a definite improvement over the SCT - seasoned observers who looked through my scope at Astrofest last year said it was the best view from an "SCT" they'd ever seen.
DT
Greg,
The big turnoff for me is the moving primary mirror. I know it's the 'traditional' way to do it, but I think it's flawed.
James
gregbradley
16-04-2010, 04:37 PM
Meade ACFs are good. Fred has proven that. Yes a moving primary is a turn off but you can simply mount a focuser to the back though and lock the mirror.
Paul Haese
18-04-2010, 05:22 PM
I wonder how this changes if at all the central 50mm or so of light cone. The older Celestrons are great for planetary imaging, but not great for DSO photography. I have not seen many hi res images of the planets with the Meade scope as they currently stand and as a result I would hazzard a guess that the light cone is slightly soft around the center. Mind you it might just be a case of people not using Meade scopes generally for planetary imaging. The best situation would be that one could do planetary at hi res and DSO's with lovely flat fields and sharp detail.
My only real gripe is the corrector collecting dew. It is bad enough for an RC8" but using a dew heater can totally wreck the quality of the images that the optics would potentially hold.
I saw the HD scopes being made in China. I did not see how they put them together but the mirrors look like standard sphericals to me.
gregbradley
18-04-2010, 07:03 PM
Marc talked to one of the US shops and was told it was a normal SCT with a corrector. So I suppose it is "merely" a well made flattener.
But then all scopes require a flattener/corrector with the big chip cameras.
Greg.
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