158 replies to this topic

[wargrafix]

Review for the Celestron 102mm AZ refractor

This scope is not a widely sold scope, but was available a large wholesaler during this year's pre-Christmas sales. The overall boxing was not very large but neatly contained all of the packaging. The telescope package is separated in 3 boxes. The head and tripod fully assembled and the spreader tray in the largest box. The OTA in the second largest box, and the small square box contained the 10mm and 20mm lens, the diagonal, a small tool for removing the battery compartment cover and the battery to power the red dot finder.

The boxes suffice for sale but you will defiantly need to repackage the scope and tripod for travel. The boxes are fairly flimsy.

The mount
Assembly
It was fairly simple to remove the AZ mount and setup. Just spread the tripod legs and extend to the required height. Please note the height is not terribly high so tall users may encounter discomfort. The spreader bar was plastic and honestly seemed to be an afterthought in terms of quality. The lightness of the mount makes this far better for grass than concrete or smoother surfaces as nudge can move it a bit easily.

Pros
For its price it’s not half bad. It’s a bit light, but for the OTA that comes with it, it services it. Motion with default accessories is alright. Very quick to setup and its excellent if you want to quickly set up for a viewing.

Cons.
Once you want to use a quality eyepiece and diagonal, you will see the flaws with the mount. Balancing issues test the ease of motion and introduces sagging when settling on a target. Don't get me wrong, its alot better that some of the bargain scope mounts out there. Build quality is decent and finished surprisingly well. Motion is where the mount suffers. It can be a bit uneven depending on the accuracy of motion. Large sweeps are great but fine tweaks aren't so fine.

The OTA
At 102mm f/6 this is a surprising character.

Cons
Let’s get the bad stuff out. I personally hate zero magnification finders. Some do...but not me. Personal preference perhaps but as wide field as this scope is, getting dead center even with the dot can be tricky. Could be positioning but the default position leaves the dot not very useful to me.

The dovetail plate. What the hell were they thinking? Its too far up for correct balancing and to short to meaningfully correct the balancing. Get rings and you will find life easier.

Finally the focuser is not horrible, I have used worse. The back focus tube has a bit of play. I am not sure if it’s a construction issue.

The dewsheild is kind if glossy as well as the tube area in front of the objective. So stray light becomes an issue.

Pros

Even with all these flaws, is an excellent OTA

Even as a achromatic, the color fringing is kept under control. It’s present for really bright targets but visually it’s not very bad.

The construction is decent and feels fairly solid. Interior is alright in terms of baffling and for photography is fairly adequate.

Eyepieces.

Not terrible but you will quickly want better eyepieces for sure because of the weak optics. The diagonal is fairly ok for daytime but for night viewing i felt it was not so great in terms of light transmission. I compare it to the regular 1.25" diagonal and it felt brighter.

Recommendations for this scope

Tripod
Get a better one is the easiest answer but I would actually recommend it for quick grab and go. A spreader lower down would help.

The OTA can be excellent. But it needs help.
First, rings will make positioning of the dovetail significantly better for balancing. Second, a better focuser probably will make fine focusing better. Finally baffling the dewshield and the area in front of the OTA will make life better in terms of reflections.

First light.

I tried on planets and was pleasantly surprised the fringing really was not disastrous. Venus was difficult though. Jupiter was small but magnificent. At 8mm on a 8-24mm I was shocked how well it held up. Saturn was too low to reliably detail quality.

For DSOs it’s a beast. Getting past the red dot finder, objects in the field of view looked very very nice. And as a challenge i pushed the limit of clarity by checking the target as it rose from the horizon. The Orion nebula showed up well less than 5 degrees above the horizon!

I am happy with the scope and with initial modifications (baffling) its a very promising scope. Not bad Celestron!

[vaskies]

Nice review. I've never seen one of these in person, but it doesn't sound like a bad package at all.

[wargrafix]

It quite good. Carried it for birding and on a wooden floor which has more friction it did not shift which i moved the OTA. Biggest shock? People were walking on the wooden floor and there was no shake or vibration whatsoever in the eyepiece. Thats why I also gave this mount a positive nod as it handles vibrations well.

[Peter Besenbruch]

The 102 AZ has been discontinued. It was marketed as the perfect beginner's scope, but lacks high power capability, because of the relatively short f-ratio (f5), and the unevenness of the mount, and the erect image diagonal. The mount has been used with lots of other tube assemblies, and never gotten good reviews. To make this more suitable for beginners, you would need to replace the tripod, mount, and eyepieces. Then you would need to add a Vixen style dovetail and rings, along with a real star diagonal. Not a real bargain for beginners.

 

Celestron scored points with the 4", f9.8. It featured better optics, and various working mounts that either were serviceable, or quite good (i.e. stable), but this one is more of a frustration machine.

[wargrafix]

Its f6.5 actually

[Peter Besenbruch]

Its f6.5 actually

 

Cool. Optics Planet got the specs wrong.

[wargrafix]

There is very little info on it. weird. I wonder why?

[Jon Isaacs]

The 102 AZ has been discontinued. It was marketed as the perfect beginner's scope, but lacks high power capability, because of the relatively short f-ratio (f5), and the unevenness of the mount, and the erect image diagonal. The mount has been used with lots of other tube assemblies, and never gotten good reviews. To make this more suitable for beginners, you would need to replace the tripod, mount, and eyepieces. Then you would need to add a Vixen style dovetail and rings, along with a real star diagonal. Not a real bargain for beginners.

 

Celestron scored points with the 4", f9.8. It featured better optics, and various working mounts that either were serviceable, or quite good (i.e. stable), but this one is more of a frustration machine.

 

The original Celestron 102AZ was an 102mm F/5 achromat, the current Celestron 102AZ is an 102mm F/6.6 refrractor, the same as the Celestron 102SLT.  OPT currently has the 102AZ in stock for $300.

 

From my point of view, the 102mm F/6.6 makes a good first scope.  It's not as capable at higher magnifications as the 102mm F/10 but it is more versatile, more compact, capable of much wider fields of view, it can be used both terrestrially and for viewing the night sky.  That 40 inch long 4 inch F/10 has been sold on a number of mounts, some without rings and with the dovetail attached directly to the OTA.

 

For deep sky, the shorter focal length of the 102AZ makes it the better scope, particular if one does not invest in a 2 inch diagonal and 2 inch eyepieces. The F/10 version is limited to a 1.55 degree TFOV, the F/6.6 version is capable of a 2.34 degree TFoV, those wide field views are nice in themselves but also make star hopping a whole lot easier.  Add a 2 inch diagonal and eyepiece, the F/6.6 can do 4 degrees, making it an excellent choice for a beginner learning to star hop, it's basically a 4 inch finder scope, that's about as good as it gets.

 

I have never owned the 102mm F/6.6, I have had a few 100mm F/6 Orion achromats..  I buy them when i see them on Astromart because I have found they do make quite good scopes for people just starting out or a second scope for a seasoned observer.  It's amazing how many own them, Tony Flanders and David Knisely are two that come to mind. They don't give the best planetary or double star views but the show the basics and they provide those views that only a short focal length refractor can provide.. they ask the question whether it really is worth it to spend thousands of dollars on a scope like the NP-101 when these scopes can provide nearly as wide a field of view and decent all around views for a few hundred dollars.. 

 

The 102mm F/10, I see that as more of a special use scope and with such a long OTA, it is more taxing of the mount. 

 

Jon

[orion61]

You should add a couple pictures, clean up the review on a couple spots, and submit it in the articles section here. More people will get exposure to it and it will be useful to beginners gathering data..

Congrats..

[wargrafix]

I was supposed to post pics, but my memory card with the unboxing died. :-( Like really really dead.

 

I guess I will do some out of box shots

 

Here is a quick 3 hours and 47 mins exposure. Please forgive the quality. I forgot to remove dewed up shots in the mix

 

[Peter Besenbruch]

The original Celestron 102AZ was an 102mm F/5 achromat, the current Celestron 102AZ is an 102mm F/6.6 refrractor, the same as the Celestron 102SLT.  OPT currently has the 102AZ in stock for $300.

 

Yes, an f6.6 is far better than an f5.

 

 

From my point of view, the 102mm F/6.6 makes a good first scope.  It's not as capable at higher magnifications as the 102mm F/10 but it is more versatile, more compact, capable of much wider fields of view, it can be used both terrestrially and for viewing the night sky. ...

The 102mm F/10, I see that as more of a special use scope and with such a long OTA, it is more taxing of the mount.

 

It is absolutely not as capable as the 4", f9.8. That actually makes it less versatile in a number of situations. Also, the CG4 holds the f9.8 quite well. The problem with the f6.6 as mounted is the mount is pretty poor, except for terrestrial viewing, again a ding against its versatility. You and I know what to do with a scope like the f6.6. We replace any eyepieces that come with it. We use a regular (2") star diagonal, replace the mount, or use another one we have lying around. After all, it's fun to do this stuff, but for a beginner it represents extra cost and frustration.

 

It's not a good beginner's scope.

Edited by Peter Besenbruch, 21 October 2015 - 03:54 PM.

[Meadeball]

Second on the quality of the CG-4 with the Omni 102 XLT. I've had one for more than a year now ... added the polar scope and Orion's EQ-3M RA drive to it last month (finally; I'd been hemming and hawing over the $100 outlay for the drive, but lemme tell ya, it's WONDERFUL having it now) ... and the whole setup does very, very well. This coming from a guy who's been in the hobby for about 40 years and owned the gamut of "medium-sized" scopes ... Celestron C8, Criterion RV-6, 8-inch Meade Starfinder EQ, coupla Mak-Cass's, etc. Good starter scope and a good scope for those of us who've finally decided portability beats bucket size.

 

Edited by Meadeball, 21 October 2015 - 02:46 PM.

[wargrafix]

Its an interesting creature and using default accessories it wasn't a failure, just not great. Its a light setup and go scope and even better for a shorter person. There is room to upgrade accessories. Tripod is steel. I set it up with my dslr and lens and it was a tad windy and it stayed put. The full scope might feel it but it makes for a good cheap tripod.


The ota is the ticket for sure but the tripod can be a good " in case i forgot something" option

[Jon Isaacs]

 

It is absolutely not as capable as the 4", f9.8. That actually makes it less versatile in a number of situations.

 

I already explained why the 4 inch F/6.6 is more versatile, why it has capabilities that the 4 inch F/10 simply does not have.  As I said, the advantage of the 4 inch F/10 is that it is better at high magnifications.  That's it.  It is too long to be an effective terrestrial scope, it's long focal length makes it difficult for starhopping unless a 2 inch eyepiece and diagonal are purchased and even then it is no better than the F/6.6 with a 1.25 inch eyepiece. The 102mm F/6.6 does stuff that you can't do with a F/10, Deep sky,bright, wide views.. 

 

The 100mm F/6s I have owned, they're easy scopes to use.. 

 

Realize, Wargrafix bought one of these and wrote this review.This review is about this scope, not some other scope that you or I might prefer for our particular purposes.  The reason I mentioned the Orion 100mm F/6 is that it is very similar to the 102mm AZ and I have found it to be an under appreciated scope, a scope that seems to fly under the radar.  I keep an eye open.. Any scope that both Tony Flanders and David Knisely own, that's a scope that deserves a closer look. 

 

Jon 

 

 

 

[Peter Besenbruch]

 

 

It is absolutely not as capable as the 4", f9.8. That actually makes it less versatile in a number of situations.

 

I already explained why the 4 inch F/6.6 is more versatile, why it has capabilities that the 4 inch F/10 simply does not have.  As I said, the advantage of the 4 inch F/10 is that it is better at high magnifications.  That's it.  It is too long to be an effective terrestrial scope, it's long focal length makes it difficult for starhopping unless a 2 inch eyepiece and diagonal are purchased and even then it is no better than the F/6.6 with a 1.25 inch eyepiece. The 102mm F/6.6 does stuff that you can't do with a F/10, Deep sky,bright, wide views..

 

I have already explained why the 4", f9.8 is more versatile. It has capabilities that the 4", f6.6 simply doesn't have, and not just optical. Aside from from the potential of being a much better high power scope, I mentioned the Astromaster mount that comes with the 4", f6.6. The mount gets bad reviews when trying to aim up. It is unbalanced by design, and the heavier the scope, the worse the balance.

 

The upshot, you have a scope that is OK for terrestrial viewing, and clumsy for astronomical viewing. In addition the prism that comes with it will limit the high power views even more than the short f-ratio. To optimize either scope you need the following:

 

F6.6: new mount, new diagonal, preferably 2", new eyepiece

f10: new diagonal, probably 2", new eyepiece

 

What you get with the f10 is a scope works well for astronomy, that has some wide field potential, and which will likely reach a usable 200x. With the f6.6, you purchase more stuff to fix a scope that will reach maybe 120x before chromatic aberration becomes objectionable. This isn't a versatile beginner's scope. This is a scope with many flaws that can be partially fixed by spending a lot more money. The only way I can see a scope like this making sense for astronomy is for an experienced user to buy it who already has a decent alt-az mount, a 2" diagonal, and the needed eyepieces.

[wargrafix]

I am actually glad it inspired a healthy debate. I do have my eyepiece and a 1.25 diagonal. Wish i had a 2" adapter for attaching my dslr or a 2" diagonal. It a nice starting scope for beginners even with the vertical pointing flaws. For us it a good scope to modify. I actually bought it for my wife and its the right weight for her.

[TexasSky]

Celestron now has a 102xlt f6.5 on an alt az mount for $299.....mount looks just "ok".....I found just the ota for $189 plus shipping on eBay.........

not to add to this debate too much, but I own lots of refractors....I have a few long focal length achros....and while I love them for planetary/lunar use....I agree that the f6.5 is a better "all around" scope.......although it will suffer on planets from CA etc as we all know......using a scope like this as a "sweeper" is just plain fun........I'll be mounting it on a explore twilight alt az as a grab and go........

i had an explore ar102, which is an awesome scope, and miss it......so in my search to replace it, I came across this new omni.....I figured what the heck, half the price, lighter, should be good quality based on other omni reviews........it should arrive early next week.....!

[TexasSky]

Hmmmm....after reading this thread closer, wargrafix's review looks to be the same scope I'm referring to!.....

there seems to be some confusion between this scope and the other cheaper celestron 102 f5 that is definitely more plastic, and not the same scope......wargrafix, maybe some pics of your scope?

[Jon Isaacs]

 

I have already explained why the 4", f9.8 is more versatile. It has capabilities that the 4", f6.6 simply doesn't have, and not just optical. Aside from from the potential of being a much better high power scope, I mentioned the Astromaster mount that comes with the 4", f6.6. The mount gets bad reviews when trying to aim up. It is unbalanced by design, and the heavier the scope, the worse the balance.

 

Peter:

 

- What does versatile mean?  It means that it can be used for a greater variety of tasks.  The 102-AZ is more versatile than my 25 inch F/5 Dob. The Dob is certainly far more capable at high powers, far more solid.. But it's not very versatile.. 

 

- Did you actually look at the Celestron 102 AZ mount?  I have never seen one in person but it appears to be a balanced design with slow motion controls.  And according to wargraphix, it's reasonably stable.  I don't know, I haven't used one.  I owned a number of the AZ-3 mounts, the one's that shipped with the 102mm F/5.. Those were unbalanced and best suited for terrestrial observation, this mount is not that mount..  

 

It seems to me you are basing your opinion on another mount. 

 

- They say the best scope is the one you use.. This scope is about 14 lbs, the 102XLT EQ, about 43lbs..

 

- Having owned both a 100mm F/6 and a 102mm F/10, I do know the relative capabilities, neither one is particularly good at high power observations, the F/10 is better but if a beginner is looking to buy a scope with the intention of using it at high magnifications, there are much better ways to spend $400 than on a 4 inch F/10 achromat.   

 

- The thing about this scope, for $300, it's difficult to find another scope with this particular blend of capabilities in this price range.  It's compact, lightweight, capable of showing the basics, the rings of Saturn, probably the Cassini division on a good night, the equatorial bands of Jupiter, maybe a shadow transit, the double-double is an easy split, Izar doable but not easy, Porrima, these days, yes, a few years ago, no.. With a 1.25 inch eyepiece, it's capable of a 2.4 degree TFoV with a 2 inch diagonal, (see below), it does 4 degrees.  

 

I agree, that darn diagonal, not good.  The diagonal that ships with the 102XLT is a better diagonal, that's a $30... A 2 inch is about $70.  One would want that in the long run with either scope. 

 

My concern with this scope is whether it has a 2 inch focuser.. I am not so sure that it does. In the photos it looks like it does but the specs say it doesn't.

 

For wargraphix with his 9.25 inch SCT, this scope seems like a good fit.  The SCT handles the high magnifications, this one is quick and easy grab and go, wide field scope.

 

Jon

 

 

 

 

[wargrafix]

Hi all. I am actually supposed to take some pics this evening. My dog isn't doing so well.


The tripod has steel legs. I wish it were heavier so it minimizes. Shifting on smooth surfaces. But heavier and a child would find difficulty. My atm baffling for the dew shield is fraying because of the scope cover edges. I hope somone can assist.please note its the one i made. The dew shield itself is fine.

I can confirm its a 2" focuser.

[earthbot1]

I have a similar scope, the 102mm f6.5 Sky Prodigy on a Celestron HD mount. Great for star cruising, I don't even have a finder on it yet. I viewed Jupiter with it this morning.
It needs to be masked and filtered to get a good view. I used the combo of LT Green and Yellow and the view was pretty good. Could easily make out the main bands. Could not

see the spot, but Jupiter is not that high in the sky yet.  I think it is best for wide star clusters, which are very enjoyable to me. It's not bad for planets with a mask and filters. 
Nebula is not as apparent as I was hoping for. Orion looks good, but even at a semi-dark sky I was disappointed in the lack of nebula glow on some objects (compared to my old Nexstar 8)
Andromeda was pretty good at the dark site. Dbl Cluster was very nice.  But it's so easy to set up and go. So it's a keeper.  

Con. I broke a plastic part on my HD tripod already. So it has some Gorilla tape holding up one leg. The plastic they use can be a bit brittle.

[wargrafix]

Nexstar 8 is an 8" sct right? See it gathers more light that the refactor. Refactors shine with contrast. Its a different beast. Not as much light in, but the views are a bit sharper.

[tony_spina]

Is the 2" focuser metal or plastic?

[wargrafix]

its a mixture. It should be changed out. Question; the drawtube has some flex, how to fix?

[Peter Besenbruch]

- Did you actually look at the Celestron 102 AZ mount?  I have never seen one in person but it appears to be a balanced design with slow motion controls.

 

I have seen two. The first is the Astromaster type mount. It appears Celestron has just released an AZ XLT version, however, that looks a lot like the Vixen Porta. Such a mount will allow for better balance and pointing at the zenith. From Wargrafix's review, and his difficulties with balance, smoothness and pointing up, I assumed he had the Astromaster mount. As I said in another thread, new mount looks interesting.

 

It also looks like the focusing draw tube on the XLT got a redesign, and now accepts 2" accessories. Both of those improvements would add considerable versatility.

 

 

My concern with this scope is whether it has a 2 inch focuser.. I am not so sure that it does. In the photos it looks like it does but the specs say it doesn't.

 

I always wonder about that. The focusing tube looks like the one that come with my C80 ED, down to the release screws that allow you to remove the 1.25" adapter. We shall see. If it allows 2" accessories, I agree, it could be a nice supplement to his C9.25. If it's on the old Astromaster mount, he might have fun mounting it on the SCT.

Edited by Peter Besenbruch, 23 October 2015 - 03:16 PM.