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CPC1100 XLT Or CPC1100 EdgeHD (+$700) for Visual Observing

cassegrain Celestron dso equipment SCT
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#1 Spacefreak1974

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Posted 02 January 2019 - 02:43 PM

Is the CPC1100 HD worth the extra $700 instead of buying the XLT version for visual observing?

 

The only thing different is the OTA as I understand, correct?

 

Jon



#2 photoracer18

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Posted 02 January 2019 - 02:53 PM

Me personally I don't think so. If I was still imaging I probably would. Notice I have a C-11 in my signature. It used to be a Hyperstar 11 but I sold off all the parts and put it back to original form.

Just remember the CPC scopes don't breakdown for travel. The OTA, forks and base stay together and you have to lift that onto the tripod or use it on a ScopeBuggy or JMI Wheelie Bars and keep it together..



#3 Stellar1

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Posted 02 January 2019 - 02:56 PM

I have done the same research before i bought my CPC1100, what i was told countless times is unless you're planning on doing serious imaging then don't bother with the edge. I have had the chance to compare mine in the field next to the same 1100 but an edge, i couldn't for the life of me see the difference, visually.



#4 HubSky

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Posted 02 January 2019 - 04:18 PM

This question comes up all the time with varying answers. 

 

When I look at the Edge whitepaper, it seems like one should be able to discern without too much effort a difference visually depending on the FOV.  I have not been able to compare the C1100 size side by side, but I can tell you when I use my TV Pan 41, N31T5, or E21 with my CPC 1100 Edge I have refractor-like pinpoint stars across the entire field all the way to the edge.  Something I don't get in my C8. 

 

So, it might matter what AFOV eyepieces one uses and the resulting TFOV for it be visually noticeable, and then whether or not the Edge optics and price difference is worth it.  YMMV.



#5 AlienRatDog

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Posted 02 January 2019 - 04:45 PM

If you are using Naglers, go with the Edge HD. Honestly though, it isn’t like a super huge difference so if money is tight, go with the XLT. The CPC HD has stronger motors as well, which really doesn’t matter unless you are doing some hardcore imaging and in that case, I would rather mount that OTA in a GEM anyways. If you want to do Altaz imaging using hyperstar and a heavy camera, then the cpc1100HD would be a good fit.

Edited by AlienRatDog, 02 January 2019 - 04:45 PM.


#6 Spacefreak1974

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Posted 02 January 2019 - 07:36 PM

If you are using Naglers, go with the Edge HD. Honestly though, it isn’t like a super huge difference so if money is tight, go with the XLT. The CPC HD has stronger motors as well, which really doesn’t matter unless you are doing some hardcore imaging and in that case, I would rather mount that OTA in a GEM anyways. If you want to do Altaz imaging using hyperstar and a heavy camera, then the cpc1100HD would be a good fit.

Not imaging, just visual



#7 Spacefreak1974

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Posted 02 January 2019 - 07:37 PM

If you are using Naglers, go with the Edge HD. Honestly though, it isn’t like a super huge difference so if money is tight, go with the XLT. The CPC HD has stronger motors as well, which really doesn’t matter unless you are doing some hardcore imaging and in that case, I would rather mount that OTA in a GEM anyways. If you want to do Altaz imaging using hyperstar and a heavy camera, then the cpc1100HD would be a good fit.

Where are the links showing that the motors are different



#8 Ryan555_1

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Posted 03 January 2019 - 12:27 AM

I was faced with this question a year ago. With the Celestron sales I went with the edge, even though I intended to be visual only. Here were my basic two reasons:

- the edge comes with three vents towards the back of the Ota. These, along with TEMPest fans, are an excellent addition to the scope. I regularly push my scope to 450x or more on steady nights. Without this active cooling, it is hard to get beyond 250x, which is what I settled for before buying the fans. If you have a non edge scope, you won't have this luxury. There are no vents.

- the edge correction. I knew I liked edge correction and I knew I would eventually get nice, wide field eyepieces. Because of this, the edge makes sense. The stars are pinpoint to the edge with a quality eyepiece.

- i remember reading that the gears are updated for heavier equipment on the back. It wasn't a big factor for me, since I was already sold.

Edited by Ryan555_1, 03 January 2019 - 12:27 AM.


#9 AlienRatDog

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Posted 03 January 2019 - 11:39 AM

Where are the links showing that the motors are different


“ Out of the box, your CPC Deluxe can track accurately for up to 30 seconds without adding a wedge, thanks to a reengineered drive train with a 6-inch brass gear, stainless steel worm gear, and both steel and nylon ball bearings.”

This is from the product description in Celestron’s website (https://www.celestro...ized-telescope#).

I had both the CPC800 and a CPC800HD and there is indeed a difference (the power supply for my regular CPC did not work on the CPCHD, I had to get the larger AC adapter as the HD required more amps).
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#10 Spacefreak1974

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Posted 03 January 2019 - 12:32 PM

Thanks guys


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#11 carolinaskies

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Posted 03 January 2019 - 02:05 PM

The visual difference is only noticeable at the edge of the field as that is the main change in design.  If in fact you created a mask to cover the outer 1" and compared the results between the two designs the result would be negligible effect.   Since when viewing the human eye is drawn to the center only when an observer expressely attempts to notice the periphery of the view will it become evident.  

If I was only choosing visual use I'd take the 700 and invest in a losmandy adapter and put a nice widefield refractor piggybacked on the scope. 



#12 Spacefreak1974

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Posted 03 January 2019 - 02:30 PM

The visual difference is only noticeable at the edge of the field as that is the main change in design.  If in fact you created a mask to cover the outer 1" and compared the results between the two designs the result would be negligible effect.   Since when viewing the human eye is drawn to the center only when an observer expressely attempts to notice the periphery of the view will it become evident.  

If I was only choosing visual use I'd take the 700 and invest in a losmandy adapter and put a nice widefield refractor piggybacked on the scope. 

Kinda what im getting at. I use what I call nice eyepieces (ES82 11 and 30mm and 14mm Baader Morpheus)  with my 8" XLT SCT and i've never noticed the edge issues. They might be there, but for me i've not noticed it.

Jon



#13 WadeH237

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Posted 03 January 2019 - 02:53 PM

If in fact you created a mask to cover the outer 1" and compared the results between the two designs the result would be negligible effect. 

I don't think so.

 

The correction is at the edges of the field, which does not change when you stop down the aperture.  If you mask the outer 1", you will get a dimmer image, with a slightly larger critical focus zone.  But the field aberrations won't change (except as a side effect of the critical focus zone, which is not significant in this example).

 

Whether the extra cost of the Edge optics are worth it or not boils down to two things:

 

Are you using wide field eyepieces.  If you doing planetary observing, or splitting doubles, or looking at small DSOs, then you will be using the center of the field which is well corrected on both scopes.  If you are using wide field eyepieces, then the aberrations at the edges of the field are significant on the classic SCT.  My C14, for example, has very noticeable coma and field curvature with my 31mm Nagler.  I've not used a 14" EdgeHD, but I presume that this would not happen.

 

How sensitive are you to field curvature?  Note that field curvature is not the aberration that causes stars to be distorted at the edges of the field.  That's usually coma on an SCT.  Field curvature means that the focal plane is curved.  This means that if you focus perfectly in the center of the field, then stars will be defocused as you move out towards the edges.  Some people are sensitive to this, and some people are not.  I think that age is a factor here.  Young eyes are able to accommodate small focus differences better than older eyes.  If you wear bifocals, then you might be more likely to notice it than someone with no glasses, or single vision glasses.

 

If neither of these two things bother you, then save $700.  If they do bother you, then consider spending more for the EdgeHD.  Also, if you are someone who buys and sells scopes, consider that the EdgeHD may be better in terms of resale value.

 

My two cents.

-Wade


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#14 junomike

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Posted 03 January 2019 - 06:38 PM

IMO the Motors/Electronics shouldn't factor much as I've seen more CPC1100 Deluxe OTA's De-forked (Due to apparent electrical fault) than the standard CPC1100.

The benefits of the Deluxe OTA are a 3rd vent (or Tempest Fan) as well as the flatter field and IMO the whiter Image (on Luna compared to Standard C11).

whether those are worth the extra $$$ (for Visual) is a personal choice. 


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#15 carolinaskies

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Posted 03 January 2019 - 08:15 PM

FWIW the Tempest fans for the Edge telescopes in my opinion are not worth the cost vs performance.  The main reason is the actual CFM the fans flow is minimal and less than optimal.  I have a 16" LX200 GPS using a single large fan with substantially more CFM and it does quite a good job.  I checked on the fans used by Tempest and then those available for DIY and found others which could flow better CFM while still maintaining vibration free operation.  Anyone who has modified SCT/Mak designs with fans use substantially more sizeable and capable fans.  Tempest offers retrofit kits for SCTs without vent/fans and you'll note they use much larger fans in those offerings.  

BTW, one of the reasons those vents are necessary is because there is no way to use a cat-cooler on an Edge design due to the internal corrector. Of course anyone who has been following the SCT group also might have kept abreast of the use of external thermal barriers to prevent the myriad of issues of an OTA body cooling rapidly vs the accompanying optics.  And how this has nearly negated the need for fans except in the most extreme situations. 

While there are many who love their Edge scopes, there are also many more who feel the XLT performs quite well.  It's an individual choice, and acknowledging the level of performance difference isn't substantially superior I think this is much like the old coatings issues.  How much of a percentage change is worth $700 vs other use of that money?  

 


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#16 Ryan555_1

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Posted 05 January 2019 - 01:52 PM

IMO the Motors/Electronics shouldn't factor much as I've seen more CPC1100 Deluxe OTA's De-forked (Due to apparent electrical fault) than the standard CPC1100. 

Erg. I sure hope not!



#17 JoeR

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Posted 05 January 2019 - 03:05 PM

Not sure about the XLT version but the Deluxe 1100 has a 6 inch 180 tooth brass gear and .75" stainless steel worm gear on the base. I used a CPC Deluxe 1100 for years on the fork mount and de-forked on a GEM. I eventually moved up to a C14 XLT and the difference is often negligible on the off axis stars. Same with my 8" EdgeHD and previous XLT C8. A bonus with the XLT SCTs is the f/6.3 reducer can be used which is cheap and compatible with all SCT aperture sizes. The EdgeHD 1100 optics require a 0.7x telecompressor specifically for that size and is considerably more expensive and heavier. I still miss my CPC Deluxe sometimes because it was so easy to setup.


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