About this product
Part Number: 91040-XLT
Q. "Should I buy the original Celestron SCT model or the new Celestron EDGE HD?".
A. The regular SCT was not designed for photography, though it does work very well when used with a 'small' sensor camera for lunar/planetary imaging. A combined f6.3 reducer/flattener is available for larger sensors but it is a compromise because flatteners and reducers perform different functions and the ideal position for the flattening component is inside the telescope, not outside. With the EDGE HD series Celestron have produced 'separate' flatteners and reducers for each model. The flattener is pre-fitted fitted inside the telescope - in the optimum position - and a dedicated reducer is available for fitting to the rear. This approach provides the large evenly illuminated flat field. There are some other mechanical benefits but they are minor compared to the EDGE HD optics. So, if you are an eye-to-eyepiece visual astronomer, or an imager using a camera with a small sensor, then the original SCT telescope will serve you well. If you are an imager using a sensor (up to APS-C size) then you are on the right page. The EDGE HD is a better suited to your needs.
Introducing the new Celestron Edge HD
- Visibly Sharper Images
- Coma-free, flat-field optics
- Enhanced Mechanical Features
- Fastar® Compatible
EdgeHD is an Aplanatic Schmidt telescope designed to produce aberration-free images across a wide visual and photographic field of view. The optical system was designed to reduce more than just off-axis star coma, but also to give an astrograph quality flat focal plane all the way to the edge of the field of view.
Celestron Edge HD White Paper pdf (6.5mb)
True Astrograph Quality
Many optical designs that advertise themselves as "astrograph" quality actually only produce pinpoint stars across a curved focal plane. While this may be acceptable for visual observing, stars will appear out of focus at the edge when used with a flat chip sensor of a digital camera. EdgeHD optics produce a focal plane more than three-times flatter than a standard Schmidt Cassegrain telescope and dramatically flatter than other competing coma-free designs. This guarantees you visibly sharp stars across some of the largest CCD chips available today.
Superior edge performance not only creates rounder, more pleasing stars but actually improves the resolution and limiting magnitude when compared to telescopes of equal aperture. Starbright XLT® Coatings coupled with Celestron's StarBright XLT coating group on every surface, EdgeHD optics gives you maximum light throughput across the widest visual and photographic spectrum.
In addition to Celestron’s new optimized optical design, the EdgeHD tube has been redesigned to make sure you get the most from your optics each and every night.
Mirror Clutches - Flexible tension clutches hold the mirror in place and reduce image shift when rotating the tube around the mount. The flexible rods allow the mirror to be held in place without putting any force or pressure on the mirror assembly, keeping the image centered in the eyepiece (or chip).
Tube Vents - Cooling vents located on the rear cell allow hot air to be released from behind the primary mirror. Each vent has an integrated 60 micron micro-mesh filter guaranteed to let warm air out without letting dust in.
Fastar Versatility - The EdgeHD is the most versatile imaging scope available today. At its native f/10 you can achieve the image scale necessary to capture the smallest of deep sky objects. With the optional reducer lens (coming soon) you can increase your field of view without sacrificing optical performance. A barlow gives you the added power for high resolution planetary, lunar and solar imaging. And of course all EdgeHD optical tubes are Fastar® compatible for ultra fast f/2 wide field imaging. Each tube has been fitted with a removable secondary mirror and are opto-mechanically aligned on a laser bench to ensure they are axially symmetric in any configuration.
All Celestron EDGE HD telescopes are fitted with the larger CGE (Losmandy-type) dovetail except for the 8-inch model which can be supplied with a Vixen-type dovetail if requested.
|Average Rating (4 Reviews): |
Saturday, 9 May 2020 | John
Prompted by FLO's system to write a review these comments are just an early impression of unboxing the 'scope and recording the disappointments none of which would prevent me ordering it again. The 'scope was delivered 'next day' reflecting FLO's usual efficiency.
I had hoped for a nice carrying case similar to that provided with my SW 80ED. No such luck. In fact the manual suggests retaining the cardboard packaging for storing the 'scope!
Mentioning the manual be aware that is carries a date of 2009 so much so that film and film grain get a mention. The manual also has an addendum discussing in detail the Fastar Compatible Optical System option for wide screen imaging. I understand that Celestron discontinued the system some years ago! The manual provides little information on astrophotography and tells the reader that additional information is detailed in publications listed at the end of the manual. That list may be there but I couldn't find it.
Given the age of the manual there is of course no mention of the Celestron 0.7 Reducer, an important item for the astro-photographer but in any case at the time of writing currently unavailable.
Wednesday, 19 February 2020 | Nikita
Scope arrived within few days after placing the order. Optics looks great. Scope required small collimation but it can be done very easily with high mag eyepiece and a bit defocused star. Package contains 2 inch Celestron diagonal with not very comfortable connection\rotation mechanism. Better to replace with Baader Clicklock visual back for SCT. In addition, package contains Celestron premium Luminos 23mm 2 inch eyepiece which looks very promising Finally, my strong advise to get heated dew shield for it because corrector plate gets foggy very quickly due to temperature difference inside and outside of tube (mirror cooling down during night). Happened to me also when scope was already ~hour and half outside. Thanks once again to FLO team for fast shipping and a great service Keep it up!
Saturday, 29 June 2019 | Rodger
After many years of using an GSO 8" F8 I decided to go for the Celestron and have been noting short of stunned as to just how good it is
Packaging - excellent double box as usual by FLO
Delivery - as always A1
Collimation was spot on from delivery with sharp stars on whole field of view with 4/3rds sensor (asi1600MMC)
Bonus - with an AOG stars can often be poor due to the OAG gathering light from the very edge of the FOV, with the Edge HD OAG guiding is much improved with 0.5 arc sec accuracy even in poor seeing
Stray light - the contrast is fantastic with the baffling working at the highest level
Speed - I was concerned that the F10 optics would be a little slow for imaging - no need to worry - it is possibly faster than my old F8 due to the excellent transmission of the coatings
Mirror locks - hold in place and do not move, however use par focal filters as auto focusers cannot work with the mirrors locked, I use Baader 2" RGB and narrowband (from FLO naturally), all stay well focused without adjustment. Takes a while to find focus initially as stars are either just visible with a quarter turn of the focus know or invisible, once near very easy to focus with a mask
Star colour - WOW! - enough said
Visual usage - No idea as I only image
Flex - None - as the whole imaging train screw thread there is no flexure, my old GSO relied on 2" push fit nosepiece which can flex with 1Kg or more hanging of the back
Only negative is that I haven't found a way of introducing a 2" light pollution filter into the main imaging train though I would rather be without it than have the flex of push fit
Overall - It's not cheap but it is awesome!!!!!
Friday, 19 August 2016 | Rafal
Decided to buy this kit to upgrade my old SkyWatcher scope. It arrived the next day and I've been nothing but impressed with it.
The optics are razor sharp, construction is very good and high-quality. Mount is easy to assemble, lightweight and very accurate. I'm able to get 90-120s unguided exposures after just a rough polar alignment, which is extremely good.
If you're thinking about getting a scope that is going to be versatile, good at pretty much everything you throw at it - and most importantly - compact and lightweight while still offering lots of apreture - this is the scope for you.
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