Celestron Evolution 9.25 telescope: after some months..

[Greymouser]

Edit: 

Think it is time I updated this, sorry if that is at all wrong, but it seemed like a good idea, now that I am past first impressions. ?

All of what I posted still stands but, I cannot help feeling I made a mistake buying this scope. Don't get me wrong, the optics are excellent, the mount is excellent, its just that they do not belong together in my opinion. The arm on the mount is not really long enough, it needs to be about ten cm longer or so, to aid clearance of the mount of the diagonal, when approaching zenith. The mount works fine, it is easy to set up and well within limits for me, regarding portability. The Go- To function is great too, as is the tracking, but this OTA is right on the limits of the payload. The tripod is bigger than that which comes with the 8 inch, but the mount is the same, which to be honest just is not good enough. Celestron claim the limit is this OTA, with a possibility of adding upto 5 lbs of extra bits, but even with me just changing out to a 2 inch diagonal, the stability is affected, for the worse, so I am not sure their facts, are true. I seriously wish I had bought the OTA, but with a better mount, such as the NEQ6 pro. Oh well, it is still usable for visual, but that is it, no matter what the advertising says. I might find a lighter OTA to go with the mount, for a portable scope and get a better mount for the 9.25 OTA, we will see. 

It is a shame I have come to this conclusion, because the idea, the concept is really excellent, just a shame the execution of it is well below par. Just a few small changes would make this setup almost perfect I would say.  I have considered sending an email to Celstron, but do not see any real point, the will not respond well, or at all probably! Hope this helps anyone else considering buying this setup, I cannot recommend it as it stands. ?

 

I am going to try and do a little review now, just so I am contributing a little bit. Try because I have little idea how to include photos, but I will attempt it. ?

I ordered the above from FLO, after seeing just how good they were from numerous people here. It arrived promptly and very well packaged, double boxed and everything intact; thank you FLO! ?

It is a very easy telescope to set up and whilst heavy, it is possible to manoeuvre the whole thing together, it is more easily moved separately and only takes a few minutes to reconnect the three parts, ie: tripod; mount and OTA. The tripod is the heaviest part and is very robust, but it does fold down to easily manageable proportions, by just turning the accessory tray around. It also appears to be very stable, at least so far as my present experience shows.

The fact that this scope comes with an inbuilt battery was a major selling point for me and it comes with several adapters to make it chargeable in many locations.                                                                                                    

 

The first night I set it up, I had problems because as FLO warn, it contained clouds! ? ( It seems to me that FLO are missing a trick there, the stickers raised a smile for me and I feel sure similar stickers would sell well... ) I struggled to align the RDF to the scope due to intermittent cloud; the poor quality RDF and my poor confidence levels. Anyway, I did set up a few nights later and sorted alignment of the RDF, it is adequate, but I think I will have to invest in a Telrad. I was initially daunted at the prospect of aligning the mount, but in fact it is very easy and intuitive. I only used the included 40 mm eyepiece and only guessed at centre, but it turned out to be adequate for visual, at least for me. It then went to the subsequent targets, almost getting them in the centre of the eyepiece every time. I did have a  Sky-watcher 12.5mm illuminated reticule eyepiece, but to be honest I am not impressed with that, it is not much good and the illumination drowns out the use to which I wish to put it; I may well try again though, in case it is me at fault.  I did my best to get a little session in, even though conditions were far from perfect. I am well impressed with the quality of the optics, which are the best I have experienced; super sharp and clear and thankfully in no need of collimation. ( Thank you for that too FLO! )  I enjoyed the couple of hours and only wished for longer and less light pollution! Ah well, we must all cope with what we have, rather than what we want! ?

Spotlight!:

The tree of doom, ( ? ) is annoying, but even though it is growing still, it is the least of my problems! Here is the scope set up a few days later, ready for observation and in hiding! It was sunny after all and I was optimistic. I was wrong to be and forgot to check the forecasts!

In summary, I would have to say this is a very good scope and I cannot wait to get it to a a dark sky site. There is some vibration, some disturbance in the eyepiece when you knock the mount, but it quickly settles. The optics are superb, but I do wonder how much better than my 6 inch newt, they are; I suspect not enough considering the difference in price. The mount and tripod more than make up for that without any doubt. I would say the included 40mm eyepiece is great, not sure about the 13mm one though. I guess that is no great surprise!  I had no trouble with dew at all, perhaps no surprise considering the time of year and my improvised dewshield. Luckily I got the astrozap heated dewshield today, so I hope that continues. I can not see any markings on the legs of the tripod, as stated, but that is no great problem, it is easy enough to get level. 

Next I will attach the focal reducer and give that a go, when the weather and other commitments permit. I now have a problem though: aperture! How good will a 14 inch dob be by comparison? ? ( Sorry wife... )

[noah4x4]

It is a superb scope Greymouser. I have the 8" Evolution. But it is an Alt-Az and I see your mention of a focal reducer (£100). Next it will probably be Televue eyepieces; a better diagonal and ever more expense. My advice is stick with the supplied EPs and any others that you might already have and wait six months before your next purchase (albeit that Starsense is a decent investment).

My aim was to regularly get away from my light polluted urban back yard but multiple trips to Kelling Heath were disappointed by cloud. I had to find a better way to observe from my light polluted back yard as travel wasn't easy. Electronic Assisted Astronomy (EAA) was an obvious solution. But that needed a camera. But due to field rotation came the question buy a wedge or buy a new mount? By now I had already spent £2,000 on optical accessories that wouldn't cut through urban light pollution. 

It might not suit everybody, but I bought a camera exceeding 4K UHD resolution.  A computer that can handle 4K UHD and a 4K UHD monitor. I put that on Hyperstar to avoid the need for wedge (or GEM); to avoid polar alignment; to avoid autoguiding etc. Now I see stuff I could never observe through an EP and have £2,000 of optical accessories that I never use.

My point is don't invest in a focal reducer or any other accessory until you are certain where you are heading. Oh dear.....you have  mentioned a 14" Dob. ......

 

 

 

 

 

 

 

[Greymouser]

On 19/09/2018 at 23:26, noah4x4 said:

Oh dear.....you have  mentioned a 14" Dob. ......

That was just my attempt at humour, don't worry I will try to avoid such in the future...

I dread to think what my wife would do to me if I did get one, never mind where I would store it! ?

I already have the focal reducer, I got it when I ordered the telescope, it made sense to me as I was already spending so much on the scope, another £ 99, seemed to make sense at the time. Not least because I do intend to try my hand at imaging at some point, though not for a good while yet, not least because I could not justify it to my wife, or indeed my self! However I have my eye on a second hand DSLR, a similar of which, I should be able to swing at Christmas, with luck. I also liked the idea of basically getting two scopes for the price of one, two focal lengths that is and a decent aperture. 

I too intend to get away to dark sites as often as I can, certainly at least the odd weekend away and even a holiday again. ? I also rely on the Clear Outside app, which seems fairly reliable and certainly would avoid travelling unless several forecasts agreed. Speaking of apps, I used the SkyPortal app to guide the scope, which whilst I really like it and the ease of guiding that it offers, it  is going to take time to get used to it. It is all too easy to catch one of the slewing buttons when concentrating on other things. I also have an issue with the Tablet going blank whilst I use the eyepiece, then ruining my night adaptation when I restart it. I will have to keep the screen on all the time and hope the Tablet battery lasts with that. I will fiddle with the settings and see what can be done. The other issue is that it does not get where I am with any accuracy, it puts me about 40 miles to the south, which is annoying, will that level of inaccuracy matter do you know?

I have just noticed though that I can see the moon at the moment, with large gaps in the clouds, even though the app says I cannot! ?

 

[Paz]

15 hours ago, Greymouser said:

I dread to think what my wife would do to me if I did get one, never mind where I would store it! ?I 

One tip I can provide from experience, if you ever get a big dob make sure the first time your other half sees it it is outdoors, it won't look anywhere near as ridiculously big as it will if they first see it on display in your living room!

[Greymouser]

I have to admit, before buying the Celestron 9.25, it was even worse, I even considered one of these:   https://www.firstlightoptics.com/dobsonians/sky-watcher-stargate-450p-truss-tube-dobsonian.html

On paper a similar price to the Celestron, but I considered that the number of accessories needed, would soon put the price way too high, never mind how difficult it would be to use! ? So it was between the 9.25 and 14 inch Dob, which seemed to be the limit handling wise.

I still wonder what the true limit is handling and set up wise. Another option would have been a decent mount/ tripod, such as the AZ-EQ6GT and staying with my six inch Newtonian, or maybe a larger Newt to be bought then or later. I was put off with too many people saying that it needed to be set up as a permanent set up, was too awkward to move about.

The Celestron 9.25 Evoulution, is in fact a grab and go scope. It is very easy to set up, with no piece of the set up too heavy to easily move. In fact it takes only a little longer than my Star Travel scope. The GOTO setup only making things a little longer.

Now I have the focal reducer/ corector in place, so have some more testing to do as soon as weather and opportunity allow.  ? ( I am not sure what the corrector part of the item actually corrects really... ?) 

Edit: Well I have now used the scope with the focal reducer in place. ?

Whilst it is billed as mainly to improve imaging, it certainly seems to improve visually too. I will have to experiment further, because I first used the scope on a moonless night at F10, last night with the focal reducer in place, F6.3, there was a full moon, which made things a littler more interesting!  Certainly the view of M31 was wider and seemed sharper, but that may have been my imagination. I am sure I saw more detail, which is surprising considering the full moon, I suppose it may have been just me, if I am being negative, but it did seem better.

It really does make a two scopes for one in my opinion alone, not least because it makes it easier for lower magnifications. The 40mm eyepiece at F10 gives a Magnification of 58.75, at F6.3 it is 37, I think, even though they advise not to use an eyepiece longer than 35mm at 6.3! Never mind, with several eyepieces it seems to have improved things.

Considering the thing cost £99, it seems to be a good buy, especially when you consider that I spent £2349 on my scope. Even more so considering the future benefits when I dip my toes into imaging...

[Greymouser]

Thin it is time I updated this, sorry if that is at all wrong, but it seemed like a good idea, now that I am past first impressions. ?

All of the above I posted still stands but, I cannot help feeling I made a mistake buying this scope. Don't get me wrong, the optics are excellent, the mount is excellent, its just that they do not belong together in my opinion. The arm on the mount is not really long enough, it needs to be about ten cm longer or so, to aid clearance of the mount of the diagonal, when approaching zenith. The mount works fine, it is easy to set up and well within limits for me, regarding portability. The Go- To function is great too, as is the tracking, but this OTA is right on the limits of the payload. The tripod is bigger than that which comes with the 8 inch, but the mount is the same, which to be honest just is not good enough. Celestron claim the limit is this OTA, with a possibility of adding upto 5 lbs of extra bits, but even with me just changing out to a 2 inch diagonal, the stability is affected, for the worse, so I am not sure their facts, are true. I seriously wish I had bought the OTA, but with a better mount, such as the NEQ6 pro. Oh well, it is still usable for visual, but that is it, no matter what the advertising says. I might find a lighter OTA to go with the mount, for a portable scope and get a better mount for the 9.25 OTA, we will see. 

It is a shame I have come to this conclusion, because the idea, the concept is really excellent, just a shame the execution of it is well below par. Just a few small changes would make this setup almost perfect I would say.  I have considered sending an email to Celstron, but do not see any real point, the will not respond well, or at all probably! Hope this helps anyone else considering buying this setup, I cannot recommend it as it stands. ?

[Mr Spock]

I use my C9.25 on an EQ6. It's a perfect match

[AKB]

I have to agree, the scope is great, the tripod is great, perhaps the mount is too, but, it’s just too small for the scope.

[Cosmic Geoff]

I saw one of these C9.25 in a showroom a month or two ago, lined up with other Celestron scopes including the C8 and the EVO 8.

I could see that the C9.25 has a chunkier mount and tripod than the C8 (=mine) but the scope is chunkier too.  The EVO 8 tripod looked like mine.

This sounds like the same complaint often levelled against the SE6/8 mount of the very popular C8- that it's not steady enough for the weight of the OTA. To which I respond: true, but it's a portable visual mount, not an imaging mount, and if you want a mount with a higher level of stiffness, buy accordingly.   

[JG777]

You might get some vignetting if you use a 2 inch star diagonal and a focal reducer.

I have the same scope as you and I absolutely love it. Mine has a FT focusser and Starsense as well and no real issues other than occasional WiFi disconnects which I cured by getting the add on WiFi adapter . I don`t do AP just visual. I do use a 2 inch SD but everything clears the base of the mount and balance is not an issue. the mount is completely untroubled by the scope being near the end of the rail and tracks like a charm all evening so I am puzzled by your stability issues? I have had many many great nights out with this scope with the only issue being cool down times but a Lymax cat cooler reduced that issue for me. My next scope down is a 6 inch F5 reflector and although it is very good it cannot beat the sheer grab of the 9.25 for DSO. It can however do wide field objects often better than the 9.25.  Damping times are relatively short  on the Evo as well, all in all there is little to dislike. If I had one complaint it is the weight of it all, I do not really consider it grab n go. However I get the point that sometimes people just do not bond with a particular set up and it kind of emphasizes the value of seeking out a local group or society to get the chance of using or seeing kit before any triggers are pulled. 

[Greymouser]

On 11/12/2018 at 09:41, Cosmic Geoff said:

To which I respond: true, but it's a portable visual mount, not an imaging mount, and if you want a mount with a higher level of stiffness, buy accordingly.

I am sorry Geoff, I have not been clear enough, obviously. I am not interested with imaging with this OTA, with this mount, it is just not suitable at all, for several reasons. It was never my intention to image with this setup, just visual. When I get into, ( try, ) Imaging, it will either be a much better mount, such as  the NEQ6, or another more portable mount and a small refractor. I did consider Hyperstar, but have been told by several, that I should to believe the hype. But first of all I would dip my toes simply with a DSLR and a very small mount, such as the Star Adventurer, or AZGti. The thing is, for me at least and clearly not all, the OTA and the mount do not belong together. It was all right with the smaller diagonal, but clearly, again to me, at the limit as to what the mount will hold. According to Celestron too it seems. Since I have upgraded to a better two inch diagonal, the damping down times etc, are just not as good. Perhaps this is my error. I intend to do some DIY, in an attempt to reduce damping, one person suggested halved tennis balls!  I constantly found that I could not observe above about 70 degrees, which is just annoying. Is it asking too much for Celestron to make the arm on the mount ten cm or so longer? That really is all it would take, to at least solve one problem.

As for over balancing it forward JG777, well I just cannot go so far against the grain, I guess! I am a creature of habit and have been nagged constantly about balance in the past. I will have to try though, because for now at least, the NEQ6 is not an option, though I still started a thread asking about the setup of one. Either way JG777, I do love the OTA and will persevere with it. I also love the mount, it just needs a small improvement for this OTA, in my opinion. Which is why I have considered another smaller OTA, in the future. I too also own a F5 six inch reflector, but find the 9.25 much better and much easier and faster to set up.  For me it is a grab and go, in three parts, though at that limit and obviously not  as easy as my ST102 on Alt/Az. Also JG777, I have not used the reducer with the two inch diagonal, at least not yet, but had no apparent problem with the smaller diagonal. I do not care about the cooldown, I just setup with plenty of time to spare and cover against the risk of showers. ?

One last thing Geoff, The mount for the Evo 9.25 seems to be the same as the Evo 8, though the tripod is sturdier,  unless I have misjudged. I have no idea where you got the idea I wanted to image with this setup. Perhaps I am misunderstanding your post. ? I did buy accordingly Geoff, according to my wishes when I ordered this scope, it was for visual only. ? But my question still stands, why not make an apparent  small, cheap improvement to make it almost perfect?

[Cosmic Geoff]

13 hours ago, Greymouser said:

I constantly found that I could not observe above about 70 degrees, which is just annoying. Is it asking too much for Celestron to make the arm on the mount ten cm or so longer?

Why? Can you upload a photo showing why it won't go above 70 degrees?  My C8 has about 2cm clearance when pointed vertically with the 1.25" diagonal, so there is a sporting chance it would clear a bulkier 2" diagonal.

My reference to imaging was because mounts like the NEQ6 used for imaging are clearly very stable.  It follows that mounts intended for visual only are likely to be lighter, more portable and less stable...

[JG777]

I think you need to rationalise this whole balance thing, it may be true for other set ups usually imaging rigs where this may be more critical, but on the Alt AZ  Evo I can categorically state that the mount tracks better when it is front loaded or technically its unbalanced. If you cannot go above 70 degrees then either you have a slew limit set in the HC or your diagonal is colliding with the base of the mount. In the former change the limit, in the latter either move the scope further up the rail to allow clearance or if this bothers you go back to the stock 1.25 SD, however if I add my W/O durabright 1.25 using the supplied visual back there is no difference in clearance between this and my 2 inch SCT SD. May as well have the better and heavier SD on the back. The scopes and mounts performance are unaffected by the scope being near the end of the rail. Many promo images show this!

 https://www.celestron.com/products/nexstar-evolution-925#

This is how  I have been using mine for years, maybe your previous ideas on balance have created a problem that does not exist with Evolution. I don't think Celestron need to make the mount arm longer in fact that could even weaken the structure. I know Celestron drop the ball on occasions but I think they mostly thought the Evo through apart from early wifi issues. If you buy a 9.25 by default there is less clearance from the base but this is not a fault or oversight by Celestron. Its a small price for those extra photons! 

Fret less about the balance and enjoy the scope , a 9.25 is a fine tool for astronomy. 

 

 

[Cosmic Geoff]

Speaking as a mechanical engineer, I would say that there is no need to worry about balancing the 9.25 Evo around the altitude axis.  The clutch and gearing will resist any imbalance.  Experience from the USA reported on Cloudynights indicates that the C8 SE can be operated for long periods with significant added unbalanced loads without ill effect.  And the SE mounts reportedly have plastic gears while the EVos reportedly have metal gears which should be more durable.

As JG777 says, operating with a front load may well confer a practical advantage.  For one thing, perfect balance may just increase annoying backlash.   It is actually quite difficult in the absence of a manual clutch to tell whether these power alt-az mounts are balanced or not.

[Greymouser]

8 hours ago, JG777 said:

I think you need to rationalise this whole balance thing, it may be true for other set ups usually imaging rigs where this may be more critical, but on the Alt AZ  Evo I can categorically state that the mount tracks better when it is front loaded or technically its unbalanced. If you cannot go above 70 degrees then either you have a slew limit set in the HC or your diagonal is colliding with the base of the mount. In the former change the limit, in the latter either move the scope further up the rail to allow clearance or if this bothers you go back to the stock 1.25 SD, however if I add my W/O durabright 1.25 using the supplied visual back there is no difference in clearance between this and my 2 inch SCT SD. May as well have the better and heavier SD on the back. The scopes and mounts performance are unaffected by the scope being near the end of the rail. Many promo images show this!

 https://www.celestron.com/products/nexstar-evolution-925#

This is how  I have been using mine for years, maybe your previous ideas on balance have created a problem that does not exist with Evolution. I don't think Celestron need to make the mount arm longer in fact that could even weaken the structure. I know Celestron drop the ball on occasions but I think they mostly thought the Evo through apart from early wifi issues. If you buy a 9.25 by default there is less clearance from the base but this is not a fault or oversight by Celestron. Its a small price for those extra photons! 

Fret less about the balance and enjoy the scope , a 9.25 is a fine tool for astronomy. 

 

 

I cannot argue with your post and will trust it, try to as you say: " rationalise the whole balance thing. " The diagonal is indeed colliding with the base of the mount. It is true I do tend to worry too much sometimes. I will put the OTA far further forward next time weather allows, if you have done so for years, then so can I, always assuming I can get past my irrational fear of overbalancing the setup and damaging the mount... ?

[K4PDM]

I appreciate this post as I am experiencing frustration with balance isssues on my 8SE. I am using large 1.5 inch eyepieces, not two inch, but the scope/mount/tripod is quite jittery and hard to focus.

I was considering the purchase of an Evolution mount for it, and that combination would probably work well. However,  I was thinking that if I was going to spend all that money on a mount, perhaps I would go for the Evolution 9.25. Your posts indicate I would encounter the same problem with an undersized mount as I currently have.

[Greymouser]

2 hours ago, K4PDM said:

Your posts indicate I would encounter the same problem with an undersized mount as I currently have.

Quite possibly, but I am suspending my doubts, as now several people have said the same regarding the balance, so I intend to go for balancing very far forward, even though it goes against the grain, so to speak. I will update again after much testing. ?

If I was to do it again, I would still get the C9.25, it is a great OTA, but I would instead purchase a NEQ6 with it and skip the Evo mount.

[JG777]

7 hours ago, Greymouser said:

Quite possibly, but I am suspending my doubts, as now several people have said the same regarding the balance, so I intend to go for balancing very far forward, even though it goes against the grain, so to speak. I will update again after much testing. ?

A couple of reminders when you do. Ensure your Alt clutch is set tight and remember the OTA is front loaded when you do loosen the clutch for removal so it isn't a surprise! You may want to revisit any backlash settings you have set because in this configuration I found this was effectively reduced to zero. The Evos are very well behaved generally as far as backlash goes but forward balance pretty much defeated it entirely in Alt. Set an upper slew limit because most goto alt az mounts have to work harder to track at the Zenith, some do this better than others and there may be sample variation between the same scopes but generally speaking sending your mount to the zenith is not the best place to be. This also reduces any chance of collision and allows you to position the scope more accurately. 

Make sure you have the latest firmware for the motor controller. V7.13.7125 fixes a potential voltage surge on the board when a slew is commanded. You will hear the slews begin a little slower and quieter. 

Clear nights, enjoy. 

[Cosmic Geoff]

I would just like to point put that most of the weight in a SCT OTA is in the mirror at the back end, accordingly the centre of gravity of the tube will not be halfway up, but near the back end.  Adding heavy accessories such as big eyepieces, cameras etc will shift the centre of gravity even more toward the back end.  So with the Celestrons, you should clamp the OTA as far up/forward as it will go in the dovetail clamp and then forget about 'balancing' it.  The clutch and gear train will hold it.  (remember the brass rod that props the OTA up in the old fashioned alt-azimuth mounts ? .)

Also worth noting that  a severe imbalance caused e.g. by moving the OTA back/down in the clamp will move the centre of gravity away from the mount axes and may be expected to make any vibration worse.

I found my C8 SE quite badly behaved as regards backlash, particularly with the weight of a camera on the back end.  Possibly because the balance was too good, but it is actually impossible to tell with it assembled.

I may be wrong, but the Evolution mount for the C8 OTA seems to be sized for the C9.25, so a slight advantage there over the SE mount used on the C6 and C8 SE.  But the C8 SE and C8 EVO have the same tripod. 

I would also say that while these mounts are not as stable as one would like, this is a compromise. You could (I could) buy a heavier and more stable mount, but it would be heavier, cost more, and most likely be less convenient to use.  For instance, if I had an AZ-EQ6 mount I don't see myself carrying the whole mount/OTA outfit out of doors in one carry!