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Upgrading SCT 6" .

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#1 paulsky

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Posted 17 February 2017 - 09:50 AM

Hi .
I currently have a Nexstar 6 SE and I'm thinking of upgrading especially in lunar and planetary observing, which is what I mostly notice.
In principle I do not want to change my mount, I thought of a Maksutov 180, but apparently it weighs a lot for the Nexstar 6SE mount, maybe the MCT 150 model, but according to it seems to be very similar to the SCT 6 ", that is, I would not notice too much "upgrading".
Right now I am contemplating the route of the Celestron 8, since Celestron sells this model also in the SE mount, which is the same as the SCT 6 "
Would you notice much difference in planetary and lunar observation between these two telescopes? Or would there be a major difference in DS observation?
Have any of you been able to test the configuration: Goto SE mount with the Celestron 8 "?
Too many vibrations?
Too much stress for the SE mount?
Is there any C8 model that weighs less than the rest of the models?
I would like to hear your opinions and experiences.
Best regards and very grateful.
Paul



#2 Augustus

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Posted 17 February 2017 - 10:05 AM

The 8" is a bit too big for the SE mount.

 

If you really want a C8, I'd recommend getting an older one from the 1990s or earlier. Sell the 6SE though; it's too close in size.



#3 Eddgie

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Posted 17 February 2017 - 10:31 AM

SE Mount would be shakey for high power us (and I have owned one).   It works but focusing will induce a long period wiggle.  Someone might suggest that a better tripod would fix this, but I placed the mount sitting directly on to a stone patio (no tripod) and it still wiggled. 

 

C8 would be better than what you have, but not so much better that it would make you gasp.   Planets will be a bit brighter (always a good thing) and you will get a bit more authority on things like Globular Clusters (an 8" opens up a dozen or so to more resolution but the vast majority of globular will remain a smudge unless your skies are very dark). Many things though will not really be all that much better. You really need to add about 50% more aperture to see a clear and meaningful bump in performance (in my own opinion anyway.   I think almost everyone would look through a telescope with 50% more aperture than what they have and feel like the improvement was substantial). 

 

If you were going to an 8" f/6 dob with excellent mirrors, you would get much better planetary performance from where you are, and a bit more improvement in DSO than you might get with the C8.  You can get Go2 dobs too, so if you are like me and like a mount that tracks planets, then the Go2 makes a lot of sense.

 

The C8 will work on the 8SE mount though, and what I think is not sufficient for stability is purely my own opinion.  Some may find it more than acceptable and consider the trade-off of a bit of shakes against the light weight and easy setup of the SE and think that it is a more than acceptable compromise. 

 

We can't really tell you what is or is not over the threshold for you.  I used an EdgeHD 8" with binoviewers for a while and while it worked OK at 100x or less, past this and I felt like it was a bit too unstable for me.  It took a very light touch of the focuser to keep the thing from shaking. 


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#4 jallbery

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Posted 17 February 2017 - 10:37 AM

The 6SE and 8SE share the same mount, save for the bezel that surrounds the dovetail clamp.   If you remove the bezel, and put a vixen-dovetailed C8 on your 6SE mount, you have the functional equivalent of the 8SE.

 

There are many 8SE owners who participate in this forum who love their 8SEs.  If you value portability AND aperture over stability and vibration-free viewing, and require goto and tracking, the 8SE might just be the scope for you.   However, it clearly is a compromise on aperture over stability, and there are many people who believe that a C8 OTA on the 6/8SE mount is too much of a compromise.

 

C8 OTAs come up for sale rather frequently, and because there are so many of them, and because new ones are so affordable (relative to the historic cost of a C8 OTA, adjusted to inflation), the price is very attractive.   I recently bought a nice orange tube C8 on eBay for about $250 shipped.   Add  a Farpoint C8 dovetail, and a red-dot finder, and I had a C8 OTA I could use on either my Evo or AVX mounts for about $320 (I already had a spare SCT diagonal).    If you buy used, you can try out the mount/OTA combination and determine if it is for you.   If you decide the C8 is not for you, you can sell it and get most (if not all) of your money back.  Or you can buy a more substantial mount for it.

 

A C8 is substantially larger than a C6-- the bulk difference is more than it sounds.  Is a C6 redundant if you have a C8?  That depends on your priorities.   I'm probably the wrong guy to ask, though, given I've got 7 CATs ranging from 4" to 8" (two B&L 4000s, a c5, a 127mm Mak, a C6 and two C8s).  Yes, I need to reduce my clowder...

 

Good luck, whatever you choose...


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#5 martinl

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Posted 17 February 2017 - 11:30 AM

Before you start spending money, is your scope:

 

1. Perfectly collimated? ("Close enough" is not close enough with SCTs)

2. Fully cooled down?

 

If it is, then the first upgrade I would consider to a stock C6 would be a good diagonal. Perhaps a Baader T2 prism with the focusing eyepiece holder. 



#6 paulsky

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Posted 17 February 2017 - 06:38 PM

Thank you for all opinion!! very interesting..

In the first place I would like to make some points
- When making most of my observations from the backyard the subject of portability is secondary.
- According to the Bortle Scale; This would be 6 approx.
- The Dobson way, I looked at it but when I could not do a good tracking with high magnifications I discarded it.

Martin, interesting questions ..., how long should it take for a C6 to cool down, being all the time in a garage outside the house? And as for the collimation I suppose that I would have to review it accurately as it seems to be very necessary for planetary and lunar observation
On the other hand I believe that my seeing could be affected by the surroundings, since I am surrounded by small gardens and houses nearby (and street lamps), perhaps this is not the ideal environment for this type of observations .., therefore working with my maximum Magnification 220X, I never get a "stable" image, it moves a lot, sometimes I have the telescope outside 2 hours before observing ..
regards



#7 mclewis1

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Posted 17 February 2017 - 08:46 PM

Paul, I know you said you want to keep your SE mount but you might consider this idea ...

 

- buy an Evolution mount with the regular tripod. These are not sold by Celestron as a regular product but some dealers occasionally offer the mount and tripod only (no ota). You might also find one on the used market.

 

- Put your 6SE ota on the Evolution and then sell the SE mount and tripod.

 

- While you are using your C6 on the Evolution look around for an optically excellent C8. When you find one sell your C6 ota and put the C8 on the Evolution. Alternately you could wait and save up for an 8" Edge HD ota and put that on the Evolution instead.

 

This would get you just about the same portability as the SE, but with a more stable setup that works better with the C8 on it.

 

If you were really after a big improvement in visuals and had the budget you could also consider going the same route, only getting an Evolution with the heavier tripod. You could also do this in more stages (instead of trying to find the Evolution with the heavier tripod) by buying the Evolution with the regular tripod but looking around for a CPC tripod. Then later on instead of going with the C8 you could step up to the C9.25 ota which will absolutely give you a very obvious upgrade on both DSOs and planets. You would however lose some of the portability and ease of setup.


Edited by mclewis1, 17 February 2017 - 08:51 PM.

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#8 martinl

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Posted 18 February 2017 - 02:05 AM

Thank you for all opinion!! very interesting..

In the first place I would like to make some points
- When making most of my observations from the backyard the subject of portability is secondary.
- According to the Bortle Scale; This would be 6 approx.
- The Dobson way, I looked at it but when I could not do a good tracking with high magnifications I discarded it.

Martin, interesting questions ..., how long should it take for a C6 to cool down, being all the time in a garage outside the house? And as for the collimation I suppose that I would have to review it accurately as it seems to be very necessary for planetary and lunar observation
On the other hand I believe that my seeing could be affected by the surroundings, since I am surrounded by small gardens and houses nearby (and street lamps), perhaps this is not the ideal environment for this type of observations .., therefore working with my maximum Magnification 220X, I never get a "stable" image, it moves a lot, sometimes I have the telescope outside 2 hours before observing ..
regards

2 hours should be plenty for a C6 to cool down in most climates, unless the air temperature is falling rapidly.

 

It sounds like you may be limited by your location, in which case getting a larger scope is unlikely to help much. Only way to be sure is to try a better observing location and see if there is a significant difference. 



#9 rseven

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Posted 18 February 2017 - 08:07 AM

I'm kind of in the same place with my 6se. I'd like to use a C8, but I do believe my seeing conditions would result in only a few nights a year of improved views. Is that worth the price if upgrading? Who knows? It's comes down to individual tastes and preferences, not to mention the size of your bank account. The Evo mount would certainly be a nice upgrade for stability, particularly with a c8 mounted on it, again it's a fair size investment. Personally, I think this hobby can become a giant sinkhole you pour money down if you don't keep some sense of proportion. Having said that I'll probably end up pouring more bucks into an Evo at some point in the future.

 

Good luck with whatever scope you choose!

 

rich



#10 spongebob@55

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Posted 18 February 2017 - 10:31 AM

I have a 6SE.  I tried a C8 on it and found it to be unacceptable with the vibrations.  IMO, its too much for the mount, and if you start adding anything other than the RDF , 1-1/4" diagonal and light weight EPs, than only makes it worse.   So I gave up on that idea.  

I ended up buying a CPC800HD on sale.  Of course its a lot heavier than a 8SE or 8" Evolution, but it's rock steady even in windy observing conditions with those 2 arms and the heavy tripod.  Has on board GPS.  No battery though that's corrected by a little on board 12v pack.  I observe from a white/gray light pollution zone backyard and a 'darker' yellow and burnt orange sites.   There isn't much of an observable difference with the 8" on DSOs from my backyard. But I notice it at the 'darker' sites.   Still the 6SE is a great little scope and is very portable.  Add a ff/fr 6.3 reducer and you have a slightly wider and different scope.  It is so light and easy to set up, I take it on road trips.

I've been thinking of getting a smaller 127mm Mak for the SE mount for planets, the moon and doubles.   The 150 Mak is just a duplication imo and again could be too heavy and long. I tried a 80mm refractor but it didn't gather enough light and is too fast/wide for my observing likes and light pollution.

The 8" evolution could be good if all the kinks are worked out of it like the wi-fi and the slop in the alt.   Its a very portable design, and should be a bit stiffer than the SE.   They tell us the mount is stiffer than the SE.  OK, maybe.  And I'm still not sold on the tripod for it.  From what I've observed at NEAF, it has a smaller foot print tripod and its black connectors between the upper and lower legs are cast metal instead of vinyl/plastic on the SE's tripod.  (by the way, check the hex head set screws on the SE; at the tripod black connectors and also the feet.   Mine were super loose and the feet had a back and forth wobble in them which I corrected....make a big difference in the stability even with the 6).

Good luck

SB



#11 K4PDM

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Posted 20 February 2017 - 06:15 AM

I got an 8SE for Christmas and installed a RACI finder on it in addition to the red dot pointer.

It does have a case of the "shakes" but so far it is acceptable.

I think that probably, over time, the vibrations will bother me more and I will look for a solution, either a different scope, mount, or electronic focuser.

Right now I'm satisfied and "maybe" will be for a long time.



#12 jallbery

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Posted 20 February 2017 - 09:14 AM

I have a 6SE.  I tried a C8 on it and found it to be unacceptable with the vibrations.  IMO, its too much for the mount, and if you start adding anything other than the RDF , 1-1/4" diagonal and light weight EPs, than only makes it worse.   So I gave up on that idea.  

I ended up buying a CPC800HD on sale.  Of course its a lot heavier than a 8SE or 8" Evolution, but it's rock steady even in windy observing conditions with those 2 arms and the heavy tripod.  Has on board GPS.  No battery though that's corrected by a little on board 12v pack.  I observe from a white/gray light pollution zone backyard and a 'darker' yellow and burnt orange sites.   There isn't much of an observable difference with the 8" on DSOs from my backyard. But I notice it at the 'darker' sites.   Still the 6SE is a great little scope and is very portable.  Add a ff/fr 6.3 reducer and you have a slightly wider and different scope.  It is so light and easy to set up, I take it on road trips.

I've been thinking of getting a smaller 127mm Mak for the SE mount for planets, the moon and doubles.   The 150 Mak is just a duplication imo and again could be too heavy and long. I tried a 80mm refractor but it didn't gather enough light and is too fast/wide for my observing likes and light pollution.

The 8" evolution could be good if all the kinks are worked out of it like the wi-fi and the slop in the alt.   Its a very portable design, and should be a bit stiffer than the SE.   They tell us the mount is stiffer than the SE.  OK, maybe.  And I'm still not sold on the tripod for it.  From what I've observed at NEAF, it has a smaller foot print tripod and its black connectors between the upper and lower legs are cast metal instead of vinyl/plastic on the SE's tripod.  (by the way, check the hex head set screws on the SE; at the tripod black connectors and also the feet.   Mine were super loose and the feet had a back and forth wobble in them which I corrected....make a big difference in the stability even with the 6).

Good luck

SB

 

I bought the Mak to use on a 4/5SE mount, but was unhappy with the degree to which the weight of the Mak made the mount shaky (not unlike your experience with a C8 on the 6/8SE mount, and particularly in comparison to using a B&L 4000-- an OTA that weighs almost nothing-- on the 4/5SE mount).  Then I came across a deal on an Evo 6 that I couldn't pass up, and then bought bargain c8 (to be the primary OTA for the Evo) and a C5 (to use on the 4/5SE).  So now I have a C5, C5, 127mm Mak, and a C9.

 

As far as the C6 vs the 127mm Mak,  they weigh about the same, and are close to the same length.  The girth of the Mak is obviously less, but-- in general-- it does not impress me as having any significant edge in portability.    In contrast, the C5 is noticeably shorter and lighter than the Mak.   I've yet to do a detailed, direct head-to-head between the C6 and the Mak under the stars, but based on my impressions thus far, I doubt the Mak is going to out-perform the C6 on anything (any advantage the Mak has due to its smaller percentage obstruction is erased by the more substantial difference in effective aperture-- the Mak really isn't an effective 127mm scope).  YMMV...

 

FWIW, I'm very happy with the Evo mount, and it handles the C8 OTA nicely.  I haven't noticed any problems with slop in the alt, and so far, the Wifi has worked fine for me.  I do have the latest version with the USB handset.


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#13 earlyriser

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Posted 20 February 2017 - 09:24 AM

Hi .
I currently have a Nexstar 6 SE and I'm thinking of upgrading especially in lunar and planetary observing, which is what I mostly notice.
In principle I do not want to change my mount, I thought of a Maksutov 180, but apparently it weighs a lot for the Nexstar 6SE mount, maybe the MCT 150 model, but according to it seems to be very similar to the SCT 6 ", that is, I would not notice too much "upgrading".
Right now I am contemplating the route of the Celestron 8, since Celestron sells this model also in the SE mount, which is the same as the SCT 6 "
Would you notice much difference in planetary and lunar observation between these two telescopes? Or would there be a major difference in DS observation?
Have any of you been able to test the configuration: Goto SE mount with the Celestron 8 "?
Too many vibrations?
Too much stress for the SE mount?
Is there any C8 model that weighs less than the rest of the models?
I would like to hear your opinions and experiences.
Best regards and very grateful.
Paul

I've seen C8's with a carbon fiber tube for sale in the classifieds.  Don't know how much weight that saves, if any, over the aluminium tubed models.



#14 Eddgie

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Posted 20 February 2017 - 09:30 AM

Thank you for all opinion!! very interesting..

In the first place I would like to make some points
- When making most of my observations from the backyard the subject of portability is secondary.
- According to the Bortle Scale; This would be 6 approx.
- The Dobson way, I looked at it but when I could not do a good tracking with high magnifications I discarded it.

Martin, interesting questions ..., how long should it take for a C6 to cool down, being all the time in a garage outside the house? And as for the collimation I suppose that I would have to review it accurately as it seems to be very necessary for planetary and lunar observation
On the other hand I believe that my seeing could be affected by the surroundings, since I am surrounded by small gardens and houses nearby (and street lamps), perhaps this is not the ideal environment for this type of observations .., therefore working with my maximum Magnification 220X, I never get a "stable" image, it moves a lot, sometimes I have the telescope outside 2 hours before observing ..
regards

Get a Go2 Newtonian.    

 

The 8" version is $1099.  It will give you more of everything.   Better DSO, better planetary, and a wider true field by a very large measure. 

The off axis performace will also be far superior to what you can get form the C6.  The coma is lower and the field is flatter. 

 

http://www.telescope...9.uts?keyword=8

 

A big upgrade from where you are today.

 

I have owned scopes up to the C14, and the 12" Go-2 Newt has been my best planetary scope ever.  I routinely track at 440x.  If you want better planetary performance with tracking, get the 12" Newt.  Sell what you have  if you need to to raise the money. 


Edited by Eddgie, 20 February 2017 - 09:36 AM.


#15 spongebob@55

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Posted 20 February 2017 - 10:27 AM

 

Thank you for all opinion!! very interesting..

In the first place I would like to make some points
- When making most of my observations from the backyard the subject of portability is secondary.
- According to the Bortle Scale; This would be 6 approx.
- The Dobson way, I looked at it but when I could not do a good tracking with high magnifications I discarded it.

Martin, interesting questions ..., how long should it take for a C6 to cool down, being all the time in a garage outside the house? And as for the collimation I suppose that I would have to review it accurately as it seems to be very necessary for planetary and lunar observation
On the other hand I believe that my seeing could be affected by the surroundings, since I am surrounded by small gardens and houses nearby (and street lamps), perhaps this is not the ideal environment for this type of observations .., therefore working with my maximum Magnification 220X, I never get a "stable" image, it moves a lot, sometimes I have the telescope outside 2 hours before observing ..
regards

Get a Go2 Newtonian.    

 

The 8" version is $1099.  It will give you more of everything.   Better DSO, better planetary, and a wider true field by a very large measure. 

The off axis performace will also be far superior to what you can get form the C6.  The coma is lower and the field is flatter. 

 

http://www.telescope...9.uts?keyword=8

 

A big upgrade from where you are today.

 

I have owned scopes up to the C14, and the 12" Go-2 Newt has been my best planetary scope ever.  I routinely track at 440x.  If you want better planetary performance with tracking, get the 12" Newt.  Sell what you have  if you need to to raise the money. 

 

I was out with my CPC800HD last night and a friend had his 8" Orion Dob.   Observing conditions were below average with 2/5 tranparency and 2/5 seeing.  The Dob clearly showed brighter on M81/M82, Venus, and a few others DSOs/OCs.   I normally don't notice such a difference, but I've never really looked.   Is that b/c the HD SCT has 2 more surfaces the light has to go through?  The field was flatter per my buddy in the CPC HD though.  Can't wait to observe with him again.   It really has me thinking of a Dob with GoTo.   I could probably even get rid of my giant honkin' ES 40mm EP.  Only thing is I MUST be comfortable observing in a chair.  I hate to stand b/c of back and knee issues.   Didn't seem to be an issue with his 8" though.  What about the SkyWatchers?


Edited by spongebob@55, 20 February 2017 - 10:46 AM.


#16 Ranger Tim

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Posted 20 February 2017 - 02:40 PM

Don't forget one of the biggest factors in deciding dob vs. SCT. Transporting the scope. If the dob has a truss tube assy then it is less of a factor. If the dob has a base that breaks down it is even less of a factor. Upon reaching the ten inch size you have maxed out the size/performance ratio IMO. Hauling a steel tube 12 inch dob is not fun, and the base is even less so. A ten inch steel tube dob will fit across most backseats. The collapsible dobs or the truss tubes that have folding or breakdown bases are much more user friendly. The difference between 8 and ten inches of aperture is more noticeable to me than most people, so I tend to go for the most aperture I can manage for visual. After owning a 12 inch Orion Intelliscope I either want an obscenely large truss tube dob or a 10 inch tube model. Completely personal preference here.

 

SCT's are remarkable for their size vs. aperture. Finally owning one feels kind of revolutionary in a way. An 11 inch scope is supposed to be unwieldy, yet it is easy for me to handle. I had to invent ways to move my 12 inch dob around. If it weren't for the cordura nylon case (easy to slide across the floor) I would have had several hernias.



#17 jallbery

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Posted 20 February 2017 - 06:47 PM

 

Hi .
I currently have a Nexstar 6 SE and I'm thinking of upgrading especially in lunar and planetary observing, which is what I mostly notice.
In principle I do not want to change my mount, I thought of a Maksutov 180, but apparently it weighs a lot for the Nexstar 6SE mount, maybe the MCT 150 model, but according to it seems to be very similar to the SCT 6 ", that is, I would not notice too much "upgrading".
Right now I am contemplating the route of the Celestron 8, since Celestron sells this model also in the SE mount, which is the same as the SCT 6 "
Would you notice much difference in planetary and lunar observation between these two telescopes? Or would there be a major difference in DS observation?
Have any of you been able to test the configuration: Goto SE mount with the Celestron 8 "?
Too many vibrations?
Too much stress for the SE mount?
Is there any C8 model that weighs less than the rest of the models?
I would like to hear your opinions and experiences.
Best regards and very grateful.
Paul

I've seen C8's with a carbon fiber tube for sale in the classifieds.  Don't know how much weight that saves, if any, over the aluminium tubed models.

 

The carbon fiber C8s are not going to weigh substantially less than a regular c8.   Most of the mass is in the rear and front cells and the mirror.  To minimize the weight of a C8 on an 8SE mount, stick to a lightweight reflex finder and 1.25" accessories.



#18 Eddgie

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Posted 20 February 2017 - 09:51 PM

An 8" f/6 Go2 Newtionian is not at all difficult to manage.

 

The optical tube is 20 lbs.

 

The base is 33 lbs.  

 

If the OP has a place where he can store the scope standing up on the base, and with no steps to negotiate (garage, garden shed, or even a Rubbermaid tool shed), the scope can be stored on its base and moved easily with wheel barrow handles or a hand truck.




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