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Celestron 8" Edge Focal Reducer NOW AVAILABLE!

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#1 amdizack

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Posted 15 January 2013 - 06:03 PM

$299 on their site!

http://www.celestron...ens-8-inch.html

#2 budman1961

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Posted 15 January 2013 - 06:14 PM

Says PREORDER right above the word reducer......supposed to ship in March.

#3 Patrick

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Posted 16 January 2013 - 12:06 AM

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. :smirk: We'll see what happens. I don't see any words about 'preorder', but I may get an email from Adorama tomorrow...

Patrick

#4 Patrick

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Posted 16 January 2013 - 08:31 AM

Well...I got an email from Adorama this morning saying the reducer was on back-order (as expected :( )! :grin:

However, it's still less expensive there than I've seen elsewhere. :smirk:

Patrick

#5 DrOxygen

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Posted 16 January 2013 - 11:56 AM

Sigh... I've been waiting patiently for a reducer for my 9.25 Edge...

#6 Darren Drake

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Posted 16 January 2013 - 12:05 PM

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??

#7 Patrick

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Posted 16 January 2013 - 01:01 PM

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. :smirk:

Patrick

#8 Patrick

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Posted 16 January 2013 - 01:05 PM

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! :grin:

Patrick

#9 Peter in Reno

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Posted 16 January 2013 - 01:21 PM

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

#10 David Pavlich

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Posted 16 January 2013 - 10:07 PM

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

#11 Darren Drake

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Posted 18 January 2013 - 03:12 PM

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.....

#12 Footbag

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Posted 18 January 2013 - 03:15 PM

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.

#13 Peter in Reno

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Posted 18 January 2013 - 03:39 PM

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

#14 John Miele

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Posted 18 January 2013 - 07:03 PM

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

#15 Patrick

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Posted 18 January 2013 - 11:57 PM

Looking forward to your comments, John!

Patrick

#16 rmollise

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Posted 19 January 2013 - 09:45 AM

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... :thinking:

#17 Footbag

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Posted 19 January 2013 - 09:53 AM

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... :thinking:


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.

#18 freestar8n

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Posted 19 January 2013 - 10:10 AM

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

#19 rmollise

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Posted 19 January 2013 - 12:10 PM

I have never had to crop pea-turkey with an APS-C chip. ;)

#20 Peter in Reno

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Posted 19 January 2013 - 01:01 PM

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...90/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

#21 bilgebay

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Posted 19 January 2013 - 01:39 PM

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! :grin:

Patrick


Hi Patrick,

Hope you get your reducer as promised.

But be prepared for a delay as well. 2-3 days ago I heard from a reliable source that the focal reducer was still a few months away from being available. The reason for the delay is the glass types used have a somewhat long lead time, as they are not the most common.

This kinda explains the reason for all the delays in Edge reducer deliveries. I guess Celestron guys have achieved something very difficult to match all their criteria. Instead of delivering a non-usable product, as some other companies have been doing, they endured all the negative comments for being late but at the same time, did their best to come up with a working solution. Probably, in the beginning, they didn't realize that the reducer would be such a big challenge for them.

Cheers

#22 Patrick

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Posted 20 January 2013 - 01:43 AM

Hope you get your reducer as promised.



HOPE so too, but I'd be surprised to see it on my doorstep in Feb. I just hope I don't have to wait until May. :grin:

Patrick

#23 Patrick

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Posted 21 January 2013 - 10:12 AM

I don't think the question is one of field illumination but rather showing star bloat and coma in the corners. I also think the standards of excellence have changed with advances in technology. We're seeing huge improvements in the field of astrophotography today. What may once have been acceptable is being surpassed by better equipment and techniques.

Patrick






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