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CPC 1100 Edge or no Edge?

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#1 rfr66

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Posted 04 December 2012 - 08:52 AM

I am considering a CPC 1100 for visual use only. I was wondering which version has better optics for visual use. After reading the white paper on it, it seems that the Edge HD uses two glass correctors inside of the baffle tube and the non HD version does not. Would I be wrong to assume that the regular version without the two extra pieces of glass should have a sharper image since it has less glass? I mean unless Celestron is using Zeiss quality glass or Fluorite I don't see how the corrector glass can be adding to the clarity. I understand how for AP it would be beneficial, but I don't want to pay extra for more glass that I don't need and may be adding a layer of haze to the view. Any thoughts and input on this would be greatly appreciated.

Richard

#2 Footbag

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Posted 04 December 2012 - 09:21 AM

I went from a CPC-800 to an Edge 800 HD. The Edge optics are better all around; visual or imaging. I was really WO'ed when I looked through it for the first time.

If you were imaging, I'd say it is a no brainer. Being that it's or visual you just have to decide how much pinpoint stars right to the edge are worth to you.

#3 Eddgie

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Posted 04 December 2012 - 05:20 PM

Rest assured that there is no difference in performnce at the center of the field. All of the visual performance difference is at the outside of the field of modern, ultra-wide field eyepeices, and the wider the apparent field of the eyepiece, the better the EdgeHD will look.

But at the center of the field, the EdgeHD corrector does virtually no damage that is perceptible by the human eye.

I have owned superb example of both the standard C8 and the EdgeHD 8" and at the center of the field, they perform the same.
This isn't the 1930s. All the glass elements in the EdgeHD are provided with state of the art multi-layer coatings and modern machines can crank out virtually perfect small aperture lenses all day long.

Just look though a modern 80mm ED refractor. Sample after sample has optics that would have been "Premium" even 10 years ago.

But if you are finicky, then maybe you need a 6" APO. That might provide a bit more "Clarity" than an EdgeHD 8". But only a tiny tiny bit.. It will cost you 6 times as much though.

I know, because I own one of those too...

Don't be afraid of the sub-aperture corrector. It is your friend. The modern SCT is a far better scope because of it. It is in fact the best SCT that has ever been (in my humble opinion of course).

#4 GeneT

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Posted 04 December 2012 - 06:01 PM

If I were buying that telescope, I would spend the extra for the Edge.

#5 mistyridge

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Posted 04 December 2012 - 07:31 PM

I agree with GeneT. My two Edge SCTs are the best I have owned. Don't ask me how many I have gone through :lol:

#6 MHamburg

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Posted 04 December 2012 - 08:38 PM

My Edge 11HD is so much better than my old 16" Newt.
Michael

#7 rfr66

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Posted 04 December 2012 - 09:37 PM

Thanks everybody for the advice. You have alleviated my fears and I will order the CPC 1100 Edge tomorrow. I use binoviewers almost exclusively so the edge performance will be less critical but I still want the best overall performance. Eddgie, you gave me pause for thought with the refractor. I have a TEC 180FL on order but may cancel it after hearing your rave review of the CPC. I thought the TEC would have given me other worldly views not knowing your experience of how close in performance it would really be to a great SCT.

#8 Rick Woods

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Posted 05 December 2012 - 12:55 PM

At the 8-inch level, I think the central obstruction of the SCT would cause low-contrast loss in planetary observing; so don't be too quick to cancel that TEC (if your finances are good for it). The CO becomes irrelevant above about 12 inches aperture (seeing overwhelms the CO effects), but at 8 inches there will be a difference, however slight.
If I could afford a TEC 180, I'd order one in a heartbeat! With that, you're getting the best view you can get, however good or bad that may be.

Heck - get both! :D

#9 TG

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Posted 05 December 2012 - 01:39 PM

I am considering a CPC 1100 for visual use only. I was wondering which version has better optics for visual use. After reading the white paper on it, it seems that the Edge HD uses two glass correctors inside of the baffle tube and the non HD version does not. Would I be wrong to assume that the regular version without the two extra pieces of glass should have a sharper image since it has less glass? I mean unless Celestron is using Zeiss quality glass or Fluorite I don't see how the corrector glass can be adding to the clarity. I understand how for AP it would be beneficial, but I don't want to pay extra for more glass that I don't need and may be adding a layer of haze to the view. Any thoughts and input on this would be greatly appreciated.

Richard


Your assumptions about Zeiss/fluorite/etc. are faulty. You can buy the Berry/Ceragioli/Smith book which has the Edge HD design analyzed in it to see there's no need for fluorite in the design to give excellent images. As Eddgie says with modern coatings and machines, turning out small, virtually perfect lenses is all in a day's work for optical companies.

Here's my experience with the C11HD:

1) 1n good-to-excellent seeing, split the Double-Double pair at high powers, placing one at center of the field. In the HD version of the scope, the second pair at field edge stays sharp, showing single diffraction rings around the components. In the non-HD version, you see mush.

2) Use a wide-field eyepiece to view the Moon. It stays sharp from center to field-edge. In a non-HD scope, the view deteriorates toward the field edge and if you have to examine anything there, you need to recenter.

For pure planetary viewing and faint fuzzies, an HD won't necessarily provide you a better experience. Only you can decide whether your viewing plans will benefit from paying a premium for the HD version.

Tanveer.

EDIT:
PS. I see that you've already gone with the Edge HD option but are planning to use binoviewers. The fly in the ointment is that for optimal performance the above 8-in HD scopes need 5.75" of back-focus (5.25" for the 8"). Binoviewers typically eat up 5". While you can refocus to add more back-focus, this, I suspect, will degrade images in the Edge HD. An option is to use a barlow ahead of the BV to increase the back-focus without needing to refocus from optimal back-focus but this increases the already long focal length and requires larger long-focal length eyepieces.

#10 rfr66

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Posted 05 December 2012 - 05:01 PM

Thank you for the visual description of what to expect when looking through the scope. It was very helpful. I was planning on using the binoviewer with an Alan Glee reducer for wider angle views of DSO. For planets I would use an AP Barcon or Baader FFC ahead of the diagonal. Hopefully those combinations will work. But if I receive the TEC180 then I can use that for planets and the CPC for DSO exclusively.

I went to order the CPC 1100HD today from Company Seven and was given some food for thought. They said that the corrector lenses in the baffle tube in the CPC HD are prone to retaining moisture due to seeling off the baffle tube and in time will cause residue buildup on the lenses as the moisture evaporates. Also that the location of the lenses make it difficult to work on the scope for any repair or cleaning. Also they found the scope susceptible to vibration from shipping and often had screws and other things come loose and they would have to use loctite. He was speaking from a longevity stand point as the scope new would perform well out of the box as long as the screws were still tight. His recommendation was for the Meade 12" as it didn't use any extra lenses to correct the field. It's built into the shape of the front corrector plate. In any event, I am now totally confused as to my purchasing decision and have not gone ahead with the order yet. From all the feedback that I've received here, I know that whichever SCT it is, it will definitely be a flat field version.

#11 TG

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Posted 05 December 2012 - 07:28 PM

Thank you for the visual description of what to expect when looking through the scope. It was very helpful. I was planning on using the binoviewer with an Alan Glee reducer for wider angle views of DSO. For planets I would use an AP Barcon or Baader FFC ahead of the diagonal. Hopefully those combinations will work. But if I receive the TEC180 then I can use that for planets and the CPC for DSO exclusively.

I went to order the CPC 1100HD today from Company Seven and was given some food for thought. They said that the corrector lenses in the baffle tube in the CPC HD are prone to retaining moisture due to seeling off the baffle tube and in time will cause residue buildup on the lenses as the moisture evaporates. Also that the location of the lenses make it difficult to work on the scope for any repair or cleaning. Also they found the scope susceptible to vibration from shipping and often had screws and other things come loose and they would have to use loctite. He was speaking from a longevity stand point as the scope new would perform well out of the box as long as the screws were still tight. His recommendation was for the Meade 12" as it didn't use any extra lenses to correct the field. It's built into the shape of the front corrector plate. In any event, I am now totally confused as to my purchasing decision and have not gone ahead with the order yet. From all the feedback that I've received here, I know that whichever SCT it is, it will definitely be a flat field version.


I live in close-to-100%-humid-all-the-time Seattle area. I have yet to experience what the C7 guy is hallucinating about. Dew on the corrector, sure. Moisture on corrector lenses??? They are deep inside the baffle tube. You would have to have the garden hose inside your SCT to get them wet or else be observing underwater. The baffle tube is not a service port for any SCT of any kind. I can't imagine what kind of servicing they want to do. In any event, removing the secondary and reaching in (for the larger SCT sizes) would be what I'd do had I the need to access the insides. I can't speak to having screws, etc. rattle loose. Mine arrived well packed in perfect collimation. This was 2+ years ago but perhaps earning money has gone to the head of the Chinese and they're slacking off now :lol:.

An important point Meade's "Advanced" series scope: it's a coma corrected scope but does not have a flat-field. You need an extra corrector for that. If you have any problems with eye-accomodation, a curved field is not going to make you happy. In addition, the Meade secondary is said to be aspheric vs. Celestron's confirmed spherical one. Aligning aspheric secondaries is never fun. Ask any R-C or classical cassegrain owner.

I had a good impression of C7. This completely ruins it. Sheesh.

Tanveer.

#12 rmollise

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Posted 06 December 2012 - 07:40 AM

They said that the corrector lenses in the baffle tube in the CPC HD are prone to retaining moisture due to seeling off the baffle tube and in time will cause residue buildup on the lenses as the moisture evaporates. Also that the location of the lenses make it difficult to work on the scope for any repair or cleaning. Also they found the scope susceptible to vibration from shipping and often had screws and other things come loose and they would have to use loctite. He was speaking from a longevity stand point as the scope new would perform well out of the box as long as the screws were still tight. His recommendation was for the Meade 12" as it didn't use any extra lenses to correct the field. It's built into the shape of the front corrector plate. In any event, I am now totally confused as to my purchasing decision and have not gone ahead with the order yet. From all the feedback that I've received here, I know that whichever SCT it is, it will definitely be a flat field version.


I have no idea what the salesman's agenda was, but he is the only one concerned about such a thing, which has not been reported by anyone else and is IMHO a _non_ issue. ;)

Oh, and less glass does not equal "sharper" images. If that were true a Kellner would beat an Ethos. ;)

#13 EFT

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Posted 06 December 2012 - 09:33 AM

Thank you for the visual description of what to expect when looking through the scope. It was very helpful. I was planning on using the binoviewer with an Alan Glee reducer for wider angle views of DSO. For planets I would use an AP Barcon or Baader FFC ahead of the diagonal. Hopefully those combinations will work. But if I receive the TEC180 then I can use that for planets and the CPC for DSO exclusively.

I went to order the CPC 1100HD today from Company Seven and was given some food for thought. They said that the corrector lenses in the baffle tube in the CPC HD are prone to retaining moisture due to seeling off the baffle tube and in time will cause residue buildup on the lenses as the moisture evaporates. Also that the location of the lenses make it difficult to work on the scope for any repair or cleaning. Also they found the scope susceptible to vibration from shipping and often had screws and other things come loose and they would have to use loctite. He was speaking from a longevity stand point as the scope new would perform well out of the box as long as the screws were still tight. His recommendation was for the Meade 12" as it didn't use any extra lenses to correct the field. It's built into the shape of the front corrector plate. In any event, I am now totally confused as to my purchasing decision and have not gone ahead with the order yet. From all the feedback that I've received here, I know that whichever SCT it is, it will definitely be a flat field version.


Seems like someone wanted to sell a Meade. I have never heard of this problem nor, as Tanveer points out, does it make sense. Adding the lenses in the baffle tube is what prompted Celestron to add vents to the OTA in order for the OTA to not be "completely" sealed off and repair and cleaning of this scope is no different. Don't be confused by that advise, just ignore it and look for the best price you can find on the scope.

#14 korborh

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Posted 06 December 2012 - 09:34 AM

I went to order the CPC 1100HD today from Company Seven and was given some food for thought. They said that the corrector lenses in the baffle tube in the CPC HD are prone to retaining moisture due to seeling off the baffle tube and in time will cause residue buildup on the lenses as the moisture evaporates. Also that the location of the lenses make it difficult to work on the scope for any repair or cleaning. Also they found the scope susceptible to vibration from shipping and often had screws and other things come loose and they would have to use loctite. He was speaking from a longevity stand point as the scope new would perform well out of the box as long as the screws were still tight. His recommendation was for the Meade 12" as it didn't use any extra lenses to correct the field. It's built into the shape of the front corrector plate. In any event, I am now totally confused as to my purchasing decision and have not gone ahead with the order yet. From all the feedback that I've received here, I know that whichever SCT it is, it will definitely be a flat field version.


Ignore the *BLEEP* nonsense Company 7 is telling you. They probably have an agenda here.

#15 crow

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Posted 06 December 2012 - 05:26 PM

I just find what C7 told you completely bizarre.

I'm a great one for being hard on my scope, including removing the secondary to stick a cooler in, and its never given me a problem.

Edge views in good seeing are sharp and refractor like, you should be aware that conditions play a bigger part in how good things look than a refractor, its just a part of owning one.

I cancelled my order for a TEC140 a couple of weeks ago, Yuri's scopes are the best of breed with AP but I realised I'm happy with the edge. I have a beaten up ES for widefield views when I need them, including the elongated stars at the field stop. A decent binoviewer will be my option for next purchase. The edge 11 is supposed to be a good scope for this from what I can gather.

#16 rfr66

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Posted 06 December 2012 - 07:08 PM

Well, thanks all for the reassuring words of confidence with the CPC1100. C7 did say he owned both and preferred the Meade (with his own agenda) but would take two and a half months to deliver one. The true flat field and lighter weight ergonomic design of the 1100 has me hooked. Also hearing that the spherical secondary is easier to collimate is a big plus.

I've heard from AP photographers that the Edge has given them much better photos than high end refractors like the TEC. But for visual planetary work I think I will still go ahead with TEC 180 order. Here on Long Island we get pretty steady skies more often than not. Finding a night of good clarity is less common. I rarely ever see the milkyway even with a new moon down by the beach. So I would need to haul the 1100 to Cherry Springs for a real experience.

#17 teskridg

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Posted 21 December 2012 - 05:03 PM

The Company 7 guys are a bit grumpy sometimes, but I wouldn't necessarily doubt their veracity. Tim

#18 orlyandico

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Posted 21 December 2012 - 08:51 PM

i am not sure if the alan gee reducer would work with the EDGE... have you considered that?

#19 Starhawk

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Posted 22 December 2012 - 04:19 PM

I think there's just the Celestron reducer. I have been giving a move from standard to Edge HD some consideration. Does the baffle tube optics set make any difference in cooldown? Here in the desert the temperature goes screaming down at dusk and temperature equalization has turned out to be my biggest SCT issue.

As for humidity in the baffle tube, I've lived some humid places and had all sorts of optics hang out in similar locations without that problem. C7 should be very embarrassed to have employees telling people such utter nonsense. I've often thought their line about inspecting quality into scopes seriously brought their reputable status into doubt. Inventing issues and saying they should tamper with precision aligned internal components for reasons no one has encountered is beyond the benefit of the doubt.

-Rich

#20 JoeR

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Posted 23 December 2012 - 10:47 AM

I have never had issues with the corrector lenses in the baffles. In fact my CPC Deluxe cools down better than my old Nexstar 11 GPS. On heavy dew nights there have been no moisture issues expect on the corrector plate of course. The baffle is perfect. I love the sharp edge of the field I find it helps focus on really faint fuzzies if there's stars in the edge I can focus on.

For reducer the Astro-Physics CCDT67 works very well for visuals and much cheaper than Celestron. It has has a clear aperture of 44 mm so all my 2" EPs work with it with no discerning vignetting. It has not worked well for imaging so I use the Optec Lepus HD Telecompressor for that.

Another benefit not usually mentioned is the CPC deluxe has a superior mount to the standard CPC with larger gears and steel bearings.

#21 crow

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Posted 23 December 2012 - 11:23 AM

Rich, I'd say get the rear vent fans and you should be ok. I've read of people just keeping the things on during imaging, visual etc and it all worked fine.

The Celestron reducer is an impressive bit of kit, really heavy duty. You can't miss it bolted to the back of the scope. For me its usefulness in a visual role has yet to be seen, but I've only managed to experiment with it once in that regard.

#22 JMW

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Posted 23 December 2012 - 04:40 PM

I used the C11EdgeHD with the huge .7 reducer on it for several nights at the Oregon Star party. I was imaging with my refractors so I put the C11 on my Discmount DM6. I was quite pleased with it. It was the first time I had it out visually at a very dark site. It did quite well compared to modest size dobs nearby. I was using several 100 degree 'AFoV' eyepieces from the ES 9 and 14 to the Ethos 17 and 21. I also used the 31T5 and Pan41 for the widest objects.

I thought using the scope at F7 went along way to overcoming the narrow fields of views when used at F10. It made using the scope on a manual mount all the more pleasant. I used the active vent fans all night and they made quite a difference when observing Jupiter at higher powers in the early hours near dawn.

I use the

#23 crow

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Posted 23 December 2012 - 04:54 PM

Thanks Jeff, thats really good to know. Adds even more flexibility to the scope. Were you using the stock Celestron diagonal?

#24 JMW

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Posted 23 December 2012 - 08:02 PM

No. I had a 2 inch GSO diagonal from Agena Astro. I don't remember what the stock Celestron diagonal looks like. Must be in one of my parts bins.






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