amdizack
member
Reged: 08/23/12
Loc: Goodyear, AZ
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Celestron 8" Edge Focal Reducer NOW AVAILABLE!
#5624901 - 01/15/13 06:03 PM
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$299 on their site!
http://www.celestron.com/astronomy/edgehd-7x-reducer-lens-8-inch.html
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budman1961
scholastic sledgehammer
Reged: 02/25/11
Loc: Springfield, MO
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: amdizack]
#5624919 - 01/15/13 06:14 PM
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Says PREORDER right above the word reducer......supposed to ship in March.
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Patrick
Postmaster
Reged: 05/16/03
Loc: Franklin, Ohio
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: budman1961]
#5625491 - 01/16/13 12:06 AM
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I don't know if I will actually get one or not, but I just placed an order for the reducer at Adorama. They have it listed for $259.95.  We'll see what happens. I don't see any words about 'preorder', but I may get an email from Adorama tomorrow...
Patrick
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Patrick
Postmaster
Reged: 05/16/03
Loc: Franklin, Ohio
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: Patrick]
#5625758 - 01/16/13 08:31 AM
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Well...I got an email from Adorama this morning saying the reducer was on back-order (as expected  )! 
However, it's still less expensive there than I've seen elsewhere.
Patrick
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DrOxygen
member
Reged: 12/30/10
Loc: New Jersey
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: Patrick]
#5626065 - 01/16/13 11:56 AM
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Sigh... I've been waiting patiently for a reducer for my 9.25 Edge...
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Darren Drake
Carpal Tunnel
Reged: 10/09/02
Loc: Chicagoland
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: DrOxygen]
#5626084 - 01/16/13 12:05 PM
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Please forgive my ignorance but why can't a standard sct reducer be used effectively? I presume the off axis performance suffers in some way??
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Patrick
Postmaster
Reged: 05/16/03
Loc: Franklin, Ohio
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: Darren Drake]
#5626160 - 01/16/13 01:01 PM
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Yes, the standard f/6.3 reducer creates optical aberrations. The main benefit of the EdgeHD design is a flat, coma reduced field across the entire fov, so it would be nice to preserve that when using the reducer.
Patrick
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Patrick
Postmaster
Reged: 05/16/03
Loc: Franklin, Ohio
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: Patrick]
#5626168 - 01/16/13 01:05 PM
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I received a further email from Adorama with this statement:
"According to the manufacturer estimates we expect to fulfill your order by the 3rd week of February 2013."
Okay...we will see!
Patrick
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Peter in Reno
Post Laureate
Reged: 07/15/08
Loc: Reno, NV
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: Patrick]
#5626190 - 01/16/13 01:21 PM
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The original Celestron F/6.3 is not only a reducer but a corrector (or flattener) as well. The EdgeHD already has a built-in corrector/flattener so adding a corrector/flattener like Celestron F/6.3 reducer/corrector on top of an existing corrector/flattener built-in EdgeHD will be ugly. In other words, you cannot have a two correctors/flatteners connected together. It's like wearing two pairs of identical prescription glasses on top of each other.
The EdgeHD focal reducer does not contain corrector/flattener. It's probably more like tele-compressor.
I look forward to receiving focal reducer for my C-8 EdgeHD.
I like Adorama web site. They sell other Celestron products below suggested retail prices including C-11/14 EdgeHD focal reducers.
OPT Telescopes said shipments to begin April, 2013. I hope Adorama is correct about late Feburary delivery.
Peter
Edited by Peter in Reno (01/16/13 01:48 PM)
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David Pavlich
Transmographied
Reged: 05/18/05
Loc: Mandeville, LA USA
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: Peter in Reno]
#5627116 - 01/16/13 10:07 PM
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Have you considered this one? I have one of their models designed for refractors on my TEC140 and it works quite well at about a third the price of a TEC flattener.
David
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Darren Drake
Carpal Tunnel
Reged: 10/09/02
Loc: Chicagoland
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: David Pavlich]
#5630088 - 01/18/13 03:12 PM
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So what is the difference between a standard C8 with the standard focal reducer and the Edge with focal reducer? If the standard setup already has a flattener built in I would think they have similar results.....
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Footbag
Carpal Tunnel
Reged: 04/13/09
Loc: Scranton, PA
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: Darren Drake]
#5630096 - 01/18/13 03:15 PM
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The original Celestron F6.3 FF/FR didn't adequately flatten the corners of an aps-c sensor. Although we don't yet know if the Edge FR will, I expect it will.
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Peter in Reno
Post Laureate
Reged: 07/15/08
Loc: Reno, NV
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: Darren Drake]
#5630131 - 01/18/13 03:39 PM
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Quote:
So what is the difference between a standard C8 with the standard focal reducer and the Edge with focal reducer? If the standard setup already has a flattener built in I would think they have similar results.....
The standard C-8 does not have built-in flattener so a F/6.3 FR with flattener helps flatten the FOV with a small price. It has vignetting and limits to certain size CCD sensors. I don't know what's the maximum size image circle with standard FR. If the CCD sensor is larger than the maximum size of image circle, then you can remove vignetting by applying flats or cropping the image.
The EdgeHD FR does not have flattener because EdgeHD scopes already has built-in flatteners inside the baffle tube. You cannot use original F/6.3 FR with EdgeHD because you cannot have two flatteners connected on top of each other. It's like wearing two pairs of prescription glasses and it won't look right to see through two pairs of prescription glasses.
Attaching original F/6.3 FR/flattener to EdgeHD will have serious negative effects. The stars will be distorted.
I would not be surprised the EdgeHD FR will have smaller image circle than without FR. It's the nature of telecompressor (technical term for FR). Celestron web site says C-8 EdgeHD FR is optimized for APS-C sized sensors which is a fairly good size CCD sensor.
Peter
Edited by Peter in Reno (01/18/13 04:06 PM)
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John Miele
Carpal Tunnel
Reged: 05/29/05
Loc: North Alabama
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: Peter in Reno]
#5630408 - 01/18/13 07:03 PM
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My Optec Lepus reducer for the Edge 8 arrived today. I'll start a new thread to detail its design and performance in my scope...John
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Patrick
Postmaster
Reged: 05/16/03
Loc: Franklin, Ohio
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: John Miele]
#5630845 - 01/18/13 11:57 PM
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Looking forward to your comments, John!
Patrick
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rmollise
Postmaster
Reged: 07/06/07
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: Footbag]
#5631217 - 01/19/13 09:45 AM
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The original Celestron F6.3 FF/FR didn't adequately flatten the corners of an aps-c sensor. Although we don't yet know if the Edge FR will, I expect it will.
You must be producing very tiny high resolution stars, since I've NEVER had problems with stars in the corners of an APS-C frame. Hell, the R/C was designed for 35mm film, after all and worked pretty well with it... 
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Footbag
Carpal Tunnel
Reged: 04/13/09
Loc: Scranton, PA
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: rmollise]
#5631225 - 01/19/13 09:53 AM
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Quote:
Quote:
The original Celestron F6.3 FF/FR didn't adequately flatten the corners of an aps-c sensor. Although we don't yet know if the Edge FR will, I expect it will.
You must be producing very tiny high resolution stars, since I've NEVER had problems with stars in the corners of an APS-C frame. Hell, the R/C was designed for 35mm film, after all and worked pretty well with it...
Maybe my reducer was a bad one, but i did see a number of other people with similar problems. My spacing was perfect, but the stars were elongated in the corners.
The day I switched to the edge, perfect corners even at f10.
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freestar8n
Carpal Tunnel
Reged: 10/12/07
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: Footbag]
#5631243 - 01/19/13 10:10 AM
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The comparison images here show a c8 with 6.3 reducer on different ccd sizes, and the Canon 20d size is very good across most of it, but clearly goes bad in the edge and corners. That stuff would have to be cropped away or it would detract from the image, assuming it is well guided and focused.
This may have worked ok with film, but I can only imagine how big the stars were in typical film images vs. today. The comparison image here probably has fwhm's around 2.5", and film exposures from the 80's and 90's would have been longer, single exposures that were manually focused and guided - so maybe 10" fwhm. The field problems would not have been as noticeable.
So for a small ccd a regular c8 with 6.3 reducer would work well, but it wouldn't also be flat field at f/10. The reducer shown earlier in this thread would probably be fine on Edge with a small chip, but not a big one. I assume the new Celestron one designed for the 8" would be better over a wider field, but I haven't seen any images with it yet. They would need to be well guided and focused to tell how good it is.
Frank
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rmollise
Postmaster
Reged: 07/06/07
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: freestar8n]
#5631457 - 01/19/13 12:10 PM
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I have never had to crop pea-turkey with an APS-C chip. 
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Peter in Reno
Post Laureate
Reged: 07/15/08
Loc: Reno, NV
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Re: Celestron 8" Edge Focal Reducer NOW AVAILABLE!
[Re: rmollise]
#5631538 - 01/19/13 01:01 PM
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I Googled for typical size for APS-C chip and found it to be about 22mm x 15mm. My SXVR-M25C OSC camera CCD is 23.4mm x 15.6mm which is very close to APS-C.
I set the back focus to as close to 105mm with my old standard C-8, F/6.3 focal reducer and SXVR-M25C camera. I get small dark corners with this setup. The slight vignetting is easily removed by calibrating with flats.
Take a look at my sample flat taken with C-8 with F/6.3 focal reducer and SXVR-M25C camera. Notice the dark corners. This is typical if you use a large CCD sensor. The image looks bad because of JPG compression and Bayer Matrix from OSC camera.
http://imageshack.us/photo/my-images/690/flatf63.jpg/
Zooming the image looks worse. Download the image and open with your favorite viewer and it should look much better.
The Celestron F/6.3 focal reducer does a nice job of illuminating a pretty large image circle.
Peter
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