Celestron Starsense Explorer 10” Dobsonian - first impressions

[Astro_Dad]

I thought it would be useful for some to read about my first impressions of this ‘scope as it’s new to market and quite an interesting package in lots of ways…newcomers to the hobby might also find my experiences of value if deciding on a first ‘scope or upgrading to their first or a bigger Dob. I’ve previously owned a Skywatcher 10” Dob and also have experience using a Stellalyra instrument, so they are my main points of reference here. (I’m not including my Heritage 150 in the mix here as it’s not a Dob technically even though I sometimes erroneously refer to it as one! 😉)

The telescope arrived yesterday, so caveat that this most definitely an initial impression - proper road test and first light report will follow! Unfortunately time got away last night and although I finished putting everything together by that time it was dark and I really needed light to complete the alignment of the StarSense unit - so that was done today. Unfortunately I lost a good clear night but fingers crossed for tonight. 

The package itself is supplied as is standard in two parts. The Dob base arrives as the usual flat pack format and is easily assembled IKEA furniture style - nothing particularly new here but it’s interesting to find a black and Celestron branded Dob base for a change. The side reinforcing bars are a neat feature and provides good rigidity - when all assembled there is essentially no wobble when the OTA is in place - it feels sturdy and well put together. The cut outs in the side of the base itself are reminiscent of some of the Orion Dobsonians - probably slightly lighter and easier to move than my previous Skywatcher but I haven’t actually weighed - that’s just how it feels. Still to me it provides a modern design that looks a little different to most on the market. 

Movement in azimuth is smooth and I was able to get just the right level of tightness on the central bolt to achieve a good level of “nudgability”. Note that this base deploys regular Teflon pads - not the nice bearings as found on the Stellalyra’s but it still has a satisfying feel and I’d suggest marginally better smoothness wise than my previous SW. (though I admit that could be just a psychological halo effect of owning a shiny new toy…). 

A minor but nice touch is the inclusion of a small rubber pad with adhesive backing for placing onto the inner side of the base, cushioning the scope as it swings to an upright position. 

The OTA itself if geometrically speaking the same as other Synta’s as far as I can tell - at F4.7 it is the same length as the SW equivalent and - I’ve not checked the specs but feels the same weight wise. (That is actually slightly shorter and slightly lighter than the SL equivalent - marginal but for me definitely noticeable!) 

I won’t comment to much on the aesthetic - personally I like the silver design but it’s pure personal preference vs the classy gloss look of the SL or the sleekness of the SW white…

The big differences though to others are the carrying handle and the StarSense cradle unit. The handle is such a simple but effective addition I am not sure why other manufacturers don’t add one as standard- I can see why so many on this forum add one as a simple DIY mod! Nice to have the control knob at the top end of the instrument too. It always felt like that was an obvious missing feature on the SL version. So much better slewing the ‘scope around with that than grasping the outer edge of the tube. 

The tension control knobs work well and add  a flash of Celestron orange to the design… looks to hold position well testing a range of eyepieces but I no longer have a RACI finderscope to hand to really test adding significant additional weight. Looks similar to the Orion set up and works similarly to the SW rods, slightly easier to use but overall not as convenient to use as the SL models in this regard. To move the OTA outside on its own the knobs need to be completely removed - not as handy as the SL design, but a minor point. 

Jumping around a bit but back to the tube- the focuser is a standard Crayford style - single speed (unlike the quality dual speed unit in the SL) and feels as smooth as any I’ve used - but will need to test this properly in the field…

Usefully the 1.25” eyepiece adapter features a brass compression ring - I always think this a nice extra to help prevent eyepieces getting marred. 
 

The StarSense Explorer feature is the clear USP here though - I won’t go into how plate solving tech works as there is plenty to read up on that elsewhere and from experts who have been using it for years in a different form. This was the feature in my first scope - the 130mm reflector version - that got me seriously hooked on practical astronomy after years of general theoretical interest - it is the same set up here. Very easy to set up by aligning your phone camera centrally over the mirror on the cradle and using cross hairs on the phones display to align in on a distant target (done in daylight).

The tech works well though I’m yet to actually test it on this ‘scope but from previous it is brilliant. I find it so much more engaging, immersive and just “involved”actually pushing the scope around in this Push To system vs the often frustrating and (sometimes) error prone GOTO - personal preference but I find it more appealing and relaxing observing in this way than having to engage motors and fiddle with handsets or phones to achieve alignment. Horses for courses…compared to when I first used the app (essentially a modded version of Sky Safari) the database has been expanded considerably beyond the Messier catalogue and limited stars, NGC’s etc. to a very large catalogue of deep sky objects that makes sense in a larger aperture instrument and will no doubt keep me busy for a very long time… 

A regular RDF is supplied and as noted elsewhere is positioned on the OTA in such a way that using this alone will quickly feel awkward and a strain on the back. I’ll be using my Rigel Quickfinder in a better position for those times I want to manually star hop (and I’ll definitely still do that). 

Final couple of points- good to see a quality eyepiece supplied in the box- in this case a 25mm Celestron Omni Plossl - a step up from modified Kellners/achromats.

And also to note that despite the contrary written elsewhere, collimation does not require a hex key/ screwdriver - primary mirror adjustment is achieved using the same knob arrangement as the SW. A collimating cap is supplied, and I found mine to not require much adjustment at all out of the box. 
 

I’m impressed with this so far and ahead of actually using it for observing strongly suspect this will be a long term keeper. Celestron tout their Starbright XLT coatings as being superior - I’m sure I won’t notice this difference (my flocking attempt on the SW yielded marginal results but may be just my eyes/ experience level there) but it’s nice to know I’ll be getting amongst the best options in terms of theoretical light transmission…

Interested to hear any comments or questions to help other potential buyers. 
First light report coming soon…

[bosun21]

What are the secondary adjustment screws? A nice evaluation of this scope. Trust Celestron to come up with innovation.

[Martin Meredith]

Thanks for this review and here's hoping you have a clear night soon.

I'd be interested to know how well the focuser and tensioner handles heavy eyepieces, esp. if a coma corrector is also used. My last reflector was f4.5 and really needed a corrector but perhaps at f4.7 it won't be needed.

[Astro_Dad]

1 hour ago, bosun21 said:

What are the secondary adjustment screws? A nice evaluation of this scope. Trust Celestron to come up with innovation.

These are the regular recessed allen key/ screw driver type. I guess you could use Bobs knobs on these…

[paulastro]

A good write up Andrew, I'll look forward to reading your assessment when you havemanaged to have first light.

[Astro_Dad]

4 hours ago, Martin Meredith said:

Thanks for this review and here's hoping you have a clear night soon.

I'd be interested to know how well the focuser and tensioner handles heavy eyepieces, esp. if a coma corrector is also used. My last reflector was f4.5 and really needed a corrector but perhaps at f4.7 it won't be needed.

I’ll test this later - Perhaps with a DSLR attached. I’ve never found coma to be problematic enough for me on my previous F4.7 to warrant investing in a Paracorr or similar, yes it’s there in degrees depending on eyepiece, and I’m sure the views could be improved with one. I’ve found that with my mid range BST Starguiders and similar the views are pleasing enough though.  Possibly something for the future but in no rush to splash out yet. 

Edited May 28, 2022 by Astro_Dad
Typo

[Stu1smartcookie]

Brilliant opening to what will hopefully become a very intuitive thread . 
A great start . 

[Martin Meredith]

It looks like the primary mirror cell/adjustment is completely different from the one in the Alan Dyer review (near the base of the page). i wonder if this is a 10" vs 8" difference or whether they've modified the design already.

 

[Astro_Dad]

1 hour ago, Martin Meredith said:

It looks like the primary mirror cell/adjustment is completely different from the one in the Alan Dyer review (near the base of the page). i wonder if this is a 10" vs 8" difference or whether they've modified the design already.

 

Yes was thinking the same Martin - could be a region specific difference, though seems unlikely. Perhaps Alan had an early review unit and Celestron never intended to launch that design. I wasn’t surprised though, since the product page for the optional cooling fan accessory clearly shows the collimation adjustments to be the regular non tool requiring type. Intriguing though! 

[Astro_Dad]

First light report - 28th May

Before taking the scope outside for a good period of cooling (at least 60 mins), I’d previously aligned the StarSense unit with my phone and the scopes main tube. This is a relatively quick and intuitive process that the system guides the user through via in app instructions. I used my trustee distant TV transmitter mast for the job - as I did for the alignment of the RDF as per a “standard” ‘scope. 

The “taking outside part” was as grab and go as it comes with a non collapsible solid tube 10” tube thanks to the carrying handle - really makes light work of the shop set up. I’ve also realised since my initial impressions note that the tension adjusting knobs do not need to be fully unscrewed/removed to lift off and manoeuvre. 

It was nowhere close to full darkness but in the evening twilight the distinctive red/orange Arcturus was just starting starting to shine through - I had a look through the scope at this, lining up with the RDF in the traditional way! Always good I think to remember the first star one properly views through a new scope! Bright golden/amber with quite attractive but unobtrusive  diffraction spikes all present and correct…

I left the scope to resume cooling and for the sky to darken. 

At “closeish” to the max darkness I was going to get I set about using the StarSense system - app launched (key access code used prior to unlock the plate solving feature) and allowed to image the night sky. The pointing location and “alignment” with the phones camera was completed within seconds. I decided to start off with a couple of easy to find targets to test the push to accuracy and get my eye in. The galaxy pair M81 and M82 first - the targets were found - close enough at least but required slight manual adjustment to have either target centred in the eyepiece (25mm Plossl so 48x power). Further minor adjustment was needed to have both Cigar and Bode’s galaxies framed in the eyepiece together. So very good - close enough but I’d seen slightly greater accuracy on my previous 130DX, so I wondered at this point  if I’d aligned the unit in daylight accurately enough. I spent a good few minutes on the pair allowing my eyes to become more dark adapted (I’d at this point set the app to night mode - which at least approximates non dark adapted disrupting red light). I also remembered the audio tour feature offered by the app -you can hear an audio recording of the written information - actually quite useful in some ways, but more likely a gimmick and not a feature I’d expect to use often, at least not without Bluetooth headphones. That said this could provide quite an immersive experience for a complete beginner who has not necessarily read up on the targets they intend to view ahead of observing. 

I noticed at this stage of use how smooth the azimuth movement was, confirming my initial view- very satisfying and indeed the whole set up feels reassuringly well constructed and mechanically of high quality. 

I then attempted a target I’d struggled to find a few days ago in another scope - M84, the bright elliptical galaxy in Markarian’s chain. The region in the Virgo cluster is so densely populated with galaxies it can (for me) be hard to be 100% sure I’m looking at the intended target - but I’m sure I located it using StarSense and enjoyed sweeping around the area at the numerous faint fuzzies. 

I looked up to my upper left - so swinging  Eastwards in my view - and spotted a very well defined Hurcules’ Keystone - I was genuinely quite excited now at the prospect of observing one of my favourite targets - M13. 
 

The StarSense tech got me to the point where the Great Globular was just on the outer edge of my FOV in the 25mm eyepiece. I manually adjusted to fully centre the target and from that point on in the evening completely forgot about the technology. This was my first view of M13 through a 10” aperture scope and as I’ve reported elsewhere was simply stunning, the classic “spilled sugar on black velvet” resemblance.  I spent 30 mins or so here, switching to my BST Starguider 18mm for a deeper view. I was able to resolve seemingly hundreds of stars from the outer edge quite close to the centre of the cluster, swapping between direct and averted vision. Nothing short of breathtaking. I actually wish I’d gone in further still with shorter focal length oculars, but I was so struck by the beauty of this target I just enjoyed with the two pieces I had outside with me at the time. 

Getting well into the early hours I decided to call it a night - satisfied with a superb first light experience. Keen to fine tune the alignment a little ahead of my next outing, but satisfied that even as is this seems to be as accurate as GOTO systems I’ve tried, but  with much greater speed and less fuss. 

Edited June 4, 2022 by Astro_Dad

[Martin Meredith]

Excellent first light review! There is something very appealing about combining the ease of use of a dob with the ability to find targets quickly, and all without spending time on aligning a goto system (the most tedious part of the process for me, and generally not all that accurate...). 

I see that you waited for close to maximum darkness, but do you have any feeling for whether the platesolving works during late twilight? 

Martin

[Astro_Dad]

5 hours ago, Martin Meredith said:

Excellent first light review! There is something very appealing about combining the ease of use of a dob with the ability to find targets quickly, and all without spending time on aligning a goto system (the most tedious part of the process for me, and generally not all that accurate...). 

I see that you waited for close to maximum darkness, but do you have any feeling for whether the platesolving works during late twilight? 

Martin

I tested this evening at what I’d consider “late twilight” here at latitude 54 degrees N. Arcturus was visible, as was Vega and the stars of the Plough were just barely visible. Little else obvious (apart from the moon towards the West). I pointed the scope roughly towards the area of sky Arcturus is in and I was pleased to find plate solving succeeded within seconds. I’ll need to test even earlier to see what works, but so long as just a few stars can be detected in order to determine location looks to be OK. 

[Stu1smartcookie]

15 hours ago, Astro_Dad said:

but so long as just a few stars can be detected in order to determine location looks to be OK. 

Thats what I wanted to know more than anything as some reviewers poured cold water on the accuracy and connection of the starsense  . Always great to read first hand experiences .

 

[Astro_Dad]

On 28/05/2022 at 16:36, Martin Meredith said:

Thanks for this review and here's hoping you have a clear night soon.

I'd be interested to know how well the focuser and tensioner handles heavy eyepieces, esp. if a coma corrector is also used. My last reflector was f4.5 and really needed a corrector but perhaps at f4.7 it won't be needed.

@Martin Meredith I’ve been playing around with the altitude tension adjustments recently, using heavier accessories to test if this would cause the optical tube to drift downwards during use. I have not found this to be a problem with a DSLR camera attached (with Barlow) and the phone docked as well. Even with extra weight attached to test (in the form of a series of bar magnets) the tube holds steady with lots of tension tightening to spare, so at this point no reason to suggest heavier 2” barrel eyepieces and other accessories would cause a problem. I’ll be testing a 2” eyepiece along with RACI finderscope and RDF combined in due course. 

 

[Astro_Dad]

I’ve assembled and attached the Celestron USB cooling fan accessory - not essential perhaps but reasonably priced so worth a look. 

(https://www.celestron.com/products/usb-cooling-fan-for-dobsonian-telescopes) 

Easy to put together with the supplied screws, and securely slots into the rear of the OTA. Works with the Celestron Powertank (or any USB power source) but the integrated cable is short and I think would benefit from a USB A extension cable to enhance ease of use. I think this is where the GSO/Stellalyra design has an edge in that it is conveniently AA battery powered, but not a deal breaker. Not tried in the field yet but looking forward to testing soon. 
 

[bosun21]

I have found that it’s a lot easier to use counterweights when the accessories and eyepiece weight starts to increase. With my starsense and phone along with my 8x50 RACI, Rigel Quickfinder and a heavy 2” Explore Scientific eyepiece. It takes me seconds to find the balance by moving my magnet weights up and down the tube. This means I don’t have to tighten the altitude tension adjustment much which allows smooth movements when keeping the target centered in the eyepiece..

[Sunshine]

This is all interesting as I have the 8” in my sights, just about to hit the buy now tab on this, I need a manageable deep sky scope.

[Astro_Dad]

5 hours ago, bosun21 said:

I have found that it’s a lot easier to use counterweights when the accessories and eyepiece weight starts to increase. With my starsense and phone along with my 8x50 RACI, Rigel Quickfinder and a heavy 2” Explore Scientific eyepiece. It takes me seconds to find the balance by moving my magnet weights up and down the tube. This means I don’t have to tighten the altitude tension adjustment much which allows smooth movements when keeping the target centered in the eyepiece..

Great point @bosun21 - haven’t tried this ‘scope with counterweights yet but can see would be very convenient when needing to keep a target centred. 

[johninderby]

Posh counterweights. 😁

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p11087_Orion-magnetic-Tube-Balance-Weight-for-your-Telescope---1400-grams.html

[Astro_Dad]

5 hours ago, Sunshine said:

This is all interesting as I have the 8” in my sights, just about to hit the buy now tab on this, I need a manageable deep sky scope.

I find that the 10” is certainly manageable size/weight wise, (that integrated handle really does help) but the 8” would be even more so, and would be an excellent deep sky instrument. 

Edited June 20, 2022 by Astro_Dad

[paulastro]

Can someone tell me if the finder foot for the RDF is a standard SW fitting finder foot please?  Heaven forbid I should want to buy one of these scopes, but if I did, I'd want to use an optical finder if I wasn't using the StarSense 😊.  Many thanks.

 

[Astro_Dad]

5 hours ago, paulastro said:

Can someone tell me if the finder foot for the RDF is a standard SW fitting finder foot please?  Heaven forbid I should want to buy one of these scopes, but if I did, I'd want to use an optical finder if I wasn't using the StarSense 😊.  Many thanks.

 

Yes indeed - it’s the standard Synta size.  I’ll be testing a RACI finderscope in this position imminently - for those manual occasions…

Edited June 22, 2022 by Astro_Dad
Typo

[Guest]

On 28/05/2022 at 15:34, Astro_Dad said:

I don't know if anyone already pointed this out, but it's the 8" that require hex + screwdriver. 8" vs. 10" have different way ot doing this.

 

 

I thought it would be useful for some to read about my first impressions of this ‘scope as it’s new to market and quite an interesting package in lots of ways…newcomers to the hobby might also find my experiences of value if deciding on a first ‘scope or upgrading to their first or a bigger Dob. I’ve previously owned a Skywatcher 10” Dob and also have experience using a Stellalyra instrument, so they are my main points of reference here. (I’m not including my Heritage 150 in the mix here as it’s not a Dob technically even though I sometimes erroneously refer to it as one! 😉)

The telescope arrived yesterday, so caveat that this most definitely an initial impression - proper road test and first light report will follow! Unfortunately time got away last night and although I finished putting everything together by that time it was dark and I really needed light to complete the alignment of the StarSense unit - so that was done today. Unfortunately I lost a good clear night but fingers crossed for tonight. 

The package itself is supplied as is standard in two parts. The Dob base arrives as the usual flat pack format and is easily assembled IKEA furniture style - nothing particularly new here but it’s interesting to find a black and Celestron branded Dob base for a change. The side reinforcing bars are a neat feature and provides good rigidity - when all assembled there is essentially no wobble when the OTA is in place - it feels sturdy and well put together. The cut outs in the side of the base itself are reminiscent of some of the Orion Dobsonians - probably slightly lighter and easier to move than my previous Skywatcher but I haven’t actually weighed - that’s just how it feels. Still to me it provides a modern design that looks a little different to most on the market. 

Movement in azimuth is smooth and I was able to get just the right level of tightness on the central bolt to achieve a good level of “nudgability”. Note that this base deploys regular Teflon pads - not the nice bearings as found on the Stellalyra’s but it still has a satisfying feel and I’d suggest marginally better smoothness wise than my previous SW. (though I admit that could be just a psychological halo effect of owning a shiny new toy…). 

A minor but nice touch is the inclusion of a small rubber pad with adhesive backing for placing onto the inner side of the base, cushioning the scope as it swings to an upright position. 

The OTA itself if geometrically speaking the same as other Synta’s as far as I can tell - at F4.7 it is the same length as the SW equivalent and - I’ve not checked the specs but feels the same weight wise. (That is actually slightly shorter and slightly lighter than the SL equivalent - marginal but for me definitely noticeable!) 

I won’t comment to much on the aesthetic - personally I like the silver design but it’s pure personal preference vs the classy gloss look of the SL or the sleekness of the SW white…

The big differences though to others are the carrying handle and the StarSense cradle unit. The handle is such a simple but effective addition I am not sure why other manufacturers don’t add one as standard- I can see why so many on this forum add one as a simple DIY mod! Nice to have the control knob at the top end of the instrument too. It always felt like that was an obvious missing feature on the SL version. So much better slewing the ‘scope around with that than grasping the outer edge of the tube. 

The tension control knobs work well and add  a flash of Celestron orange to the design… looks to hold position well testing a range of eyepieces but I no longer have a RACI finderscope to hand to really test adding significant additional weight. Looks similar to the Orion set up and works similarly to the SW rods, slightly easier to use but overall not as convenient to use as the SL models in this regard. To move the OTA outside on its own the knobs need to be completely removed - not as handy as the SL design, but a minor point. 

Jumping around a bit but back to the tube- the focuser is a standard Crayford style - single speed (unlike the quality dual speed unit in the SL) and feels as smooth as any I’ve used - but will need to test this properly in the field…

Usefully the 1.25” eyepiece adapter features a brass compression ring - I always think this a nice extra to help prevent eyepieces getting marred. 
 

The StarSense Explorer feature is the clear USP here though - I won’t go into how plate solving tech works as there is plenty to read up on that elsewhere and from experts who have been using it for years in a different form. This was the feature in my first scope - the 130mm reflector version - that got me seriously hooked on practical astronomy after years of general theoretical interest - it is the same set up here. Very easy to set up by aligning your phone camera centrally over the mirror on the cradle and using cross hairs on the phones display to align in on a distant target (done in daylight).

The tech works well though I’m yet to actually test it on this ‘scope but from previous it is brilliant. I find it so much more engaging, immersive and just “involved”actually pushing the scope around in this Push To system vs the often frustrating and (sometimes) error prone GOTO - personal preference but I find it more appealing and relaxing observing in this way than having to engage motors and fiddle with handsets or phones to achieve alignment. Horses for courses…compared to when I first used the app (essentially a modded version of Sky Safari) the database has been expanded considerably beyond the Messier catalogue and limited stars, NGC’s etc. to a very large catalogue of deep sky objects that makes sense in a larger aperture instrument and will no doubt keep me busy for a very long time… 

A regular RDF is supplied and as noted elsewhere is positioned on the OTA in such a way that using this alone will quickly feel awkward and a strain on the back. I’ll be using my Rigel Quickfinder in a better position for those times I want to manually star hop (and I’ll definitely still do that). 

Final couple of points- good to see a quality eyepiece supplied in the box- in this case a 25mm Celestron Omni Plossl - a step up from modified Kellners/achromats.

And also to note that despite the contrary written elsewhere, collimation does not require a hex key/ screwdriver - primary mirror adjustment is achieved using the same knob arrangement as the SW. A collimating cap is supplied, and I found mine to not require much adjustment at all out of the box. 
 

I’m impressed with this so far and ahead of actually using it for observing strongly suspect this will be a long term keeper. Celestron tout their Starbright XLT coatings as being superior - I’m sure I won’t notice this difference (my flocking attempt on the SW yielded marginal results but may be just my eyes/ experience level there) but it’s nice to know I’ll be getting amongst the best options in terms of theoretical light transmission…

Interested to hear any comments or questions to help other potential buyers. 
First light report coming soon…

I

[Astro_Dad]

10 hours ago, Millenium said:

I

Thanks @Millenium for clarifying this - I don’t think I’ve heard from anyone with hands on experience of the 8 inch model yet, but it was indeed the 8 that was reviewed and where this was mentioned. We speculated there could be a difference between the two sizes, and the product photos online seem to support this idea too. Interesting! 

[Sunshine]

Excited as I just bought the 8" thanks for your helpful post!