Celestron Nexstar 127SLT or Sky-Watcher BK MAK127 + AZ SynScan?
Hi,
I'm currently looking to buy a telescope for a bit of casual visual observing, largely planetary/lunar. Portability, compact size and relatively quick set up are important to me, and I'm also trying to keep to a fairly modest budget.
Based on my online research (and essentially zero actual experience) the Celestron Nexstar 127SLT and Sky-Watcher BK MAK127 + AZ SynScan packages seem to fit the bill. Both of these are 5" f/12 'aluminised spot' type Mak-Cass OTAs on light duty alt-az goto mounts, and both are available from Andrews Communications for a tempting A$999.
The question is whether I am right in thinking that these telescopes would be a good choice given my requirements, and if so which of the two would be the better choice? The specs are essentially identical (about the only difference I can see is that the Celestron comes with a red dot finder while the Sky-Watcher has a straight 6 x 30 finderscope) so differentiating between the two would come down to things like quality of the optics, quality of the focus mechanisms, stability of the mounts and the ease of setup/alignment/use of the mounts. Anyone with experience of these OTAs and/or mounts care to comment on their merits (or lack thereof)?
I have a Celestron 130 slt and although it is a Newtonian not a mak-cass' it gives stunning views of Jupiter, Saturn, the Moon and even the Sun (with a proper solar filter of course!). All of the SLT series share the same instruction manual so I assume that the set up will be the same. My 130 slt can fit in my backpack offering good portability and sets up in minutes.
The mounts computer/handset has given me only one problem (it gave me an error and I couldn't use the telescope until the connector cable arrived from America) but other than that it always got the alignment spot on and is really easy to use. I also believe that all the SLT mounts come with AA battery holders built in them (mine does) which is very handy. Although the batteries in mine last about 2-3 nights (but it uses 8 AA's at a time), I still invested in a Celstron Power Tank - complete with lights, radio and car jump starter.
The only problem I have had with the tripod is the fact that it is very light and can shake which gets really annoying. A few bags of rice on the accessory tray helped solve this problem.
The red dot sight I found extremely helpful down south away from light pollution as it offered a simplified view of the sky - great for beginners, but back home in light polluted skies the red dot sight could only show you what your eye can see, which is very little. At home though you can buy a dovetail finderscope which you can replace the red dot with. Also if the seeing conditions are at least mag 1, you can pick 3 bright stars and the computer will automatically align itself and you can pick any of the objects in the mounts database, meaning you don't need the finderscope after alignment.
I have had no problems with the focus mechanism and will even go so far to say that it is relatively smooth (as long as you loosen the screw, which I only recently figured out )
The only other problem I have ever had with my 130 is collimation. Celestron has implemented a pretty helpful collimation system which uses no tools but the instruction manual still shows the tool system so I had to research for quite a while to see which knob does what (just so you know the thinner one is the locking screw).
This reply is based on my experiences with my 130 SLT which uses the same mount/tripod, computer/hand controller, focus system, red dot sight and dovetail mounting system. I can not speak for the sky watcher telescope but I can say that Celestron make quality telescopes and the SLT models are great for beginners and offer great views of solar system and DSO's.
yes they are a good choice for lunar planetary (not for deep sky objects)-the mounts will be a little bit wobbly but there will be little difference between the pkg's- mak cass are good high mag scopes which require little cool down
The 127 would be a great little scope for lunar/planetary IMO I cut my teeth on a 127SLT but since Celestron and Skywatchers have the same parent company the ota should be indistinguishable from one another optically. It'd just a question of accessories.
The mounts are much the same also. Personally, I prefer the Celestron software for ease of use but there's not much in it.
With a 32mm plossl you can get slightly more than 1 degree true field of view (amount of sky from one side of the view to the other) and despite the relatively small aperture for DSOs you should get a nice contrasty view. Likewise for lunar and planetary, you might be surprised how good these can be
The great things about these scopes are that they're light and portable (even though the mount is a little flimsy) and the little Mak doesn't (usually) require collimation. Just plonk and play
Thanks for the feedback all. The consensus seems to be that these telescopes would be a good choice for what I want them for, provided I'm prepared to put a little effort into reducing tripod wobble.
Regarding the choice between the two, as Dunk points out and as I've also heard from Andrews Communications both of these packages are made by Synta Suzhou. They're not just similar telescopes, they're basically the same telescope just with different branding. The only differences seem to be the finder (red spot vs finderscope), the colour schemes and the mount firmware (is there much difference there?).
I'm not entirely sure about the alt az version of synscan as I only have the EQ version, but the Celestron has "sky align" where you just pick 3 bright stars to align with but don't strictly need to know what they are...not sure if this is on the more recent synscan firmware. Also, the Celestron software seems to need fewer key presses to achieve a goto. A small thing but still.
Hi HotDog and welcome , I have a 127mm Istar f8 refractor and it shows awesome features on the moon and planets , but as good as a scope is , it comes down to the mount and at this level of scopes the 127mm ( 5 inch ) is starting to shine on what they show weather it is a Newtonion , Mak or refractor , the mount's where it is at and that's why mine is such a great scope ,,, its the HEQ5 mount under the OTA , nice and sturdy , and easy to use .
That's me .
Brian.
In the end I did decide to go with the Celestron Nexstar 127 SLT, the decision between that and the Sky-Watcher being largely based on comments about the quick and easy set up/alignment of the Nexstar mount.
So far I'm extremely happy with my decision. This 5" goto Mak is exactly what I was after, compact and lightweight enough to be easy to store, move and set up but with enough aperture and focal length for good lunar, planetary and solar views and quick enough to set up that it's still worthwhile getting out even if I can only spare an hour or so. The included eyepieces aren't fantastic (noticeable chromatic aberration and image softness away from the middle of the field) but as far as I can tell the optics of the OTA itself are good, and collimation was spot on out of the box. For the price it really is impressive overall.
It is true that the included tripod is very wobbly but I've found that was significantly improved by using it with the legs at the minimum extension required for levelling rather than the 6-8" mentioned in the manual. With the scope that low to the ground the straight through red dot finder can be a bit awkward to use but at least the mount is then tolerably stable.
Unfortunately I was hit by the Celestron firmware corruption bug 6 days after buying the telescope, when I turned the telescope on the handset displayed "Bootloader invalid package 0080” and refused to work. According to the Celestron webpage about this problem the official solution to "my new Celestron telescope is broken" is "buy these additional Celestron accessories so that you can fix it yourself", an attitude I wasn't impressed by. Fortunately when I contacted Andrews they immediately offered to exchange the handset for a new one and updated the firmware while they were at it, very satisfied with the customer service there. To Celestron's credit when I did complain to their technical/customer support about their policy they did offer to send me the proprietary Nexstar RS-232 cable needed to re-flash the handset firmware but given that this is a known problem I still think they should be including it in the box with the telescopes.
Anyway, wobbly mount and firmware glitch aside I've been really enjoying the views of the Sun, Moon and Jupiter I've been able to get. With a cheap Lorng Perng digiscoping adaptor and my Sony RX100 I've even been able to get some half decent images. Below is my best effort to date, an image of Europa, Jupiter and Io obtained from processing a 30 second video clip in Registax 6.
I agree on the cable, they include it with the SE series and upwards and it surely can't cost much. Agree on the included eyepieces too, they don't exactly make the most of the scope. A nice 32mm plossl or (better) 24mm 68 degree design would do a nice rendition if max FOV and at a bit over 1 degree it's not all bad, and you should get lovely contrast and detail out of the scope. For shorter focal lengths...there are a lot of choices.
Some folk hang a bag of something heavy from the spreader plate to damp it a bit more, but I'd be reasonable with the term heavy as it's not made out of cast iron
I think that with my current focus on planetary/lunar/solar the item at the top of my upgrade wishlist is a nice 6 mm planetary eyepiece, probably Lorng Perng or one of their many re-badged clones. As well as lower chromatic aberration, better off axis sharpness and a little more magnification for visual observing this would also give me much more suitable magnification for the simple eyepiece projection/afocal photography I've been dabbling in. The barrel of the little 9 mm eyepiece included with the telescope is too short to clamp my digiscoping adapter to, consequently I've only been able to use the 25 mm which gives me planetary images that are a bit too small for the RX100 camera.
A better wide angle eyepiece would probably be next on the list though so that I can make the most of it when I get to take the telescope somewhere with darker skies. Aside from a few quick looks at the Orion nebula I haven't really tried any deep sky stuff yet, my horribly light polluted suburban Sydney back yard really isn't the ideal place for it.
I did try adding ballast to the tripod spreader plate and alternatively to the tripod legs when I still had the legs extended 6-8" and it didn't seem to make much difference, almost 10 seconds to settle after touching the telescope. With the legs at minimum extension and the tripod pushed firmly down into my lawn the settling time is more like 3 seconds, that I can live with.
A couple more photos from last night using a cheap Bintel x2 Barlow, the included 25 mm eyepiece, digiscoping adaptor, RX100 and AutoStackkert!2:
6mm might be a bit short for visual with average Sydney seeing, you might get more use out of an 8, and you can't beat quality glass IMO for high magnification work. If you have the budget and can stand the eye relief, a TV plossl or an ortho should maximise your visual detail and contrast.
Good to see you're getting results with your scope
Thanks Dunk, you may well be right on the eyepiece focal length. The other night while viewing Jupiter with the included 9 mm (i.e. 167x, 33x per inch) I felt it would benefit from a little more magnification which got me thinking about a 6 mm (250x) but the seeing at that time was certainly rather good, possibly exceptional for Sydney, so an 8 mm (188x) may be the better choice for most of the time.
I understand that quality eyepieces can make a big difference (after all they're just as much a part of the optical system you're looking through as the telescope optics are) but on the other hand one upside of having a slow telescope (f/12) is that the system overall is less sensitive to most aberrations of the eyepiece. I'll have to investigate my options and have a think about it.
I don't really have enough data points on Sydney seeing, but from what other folk say it's not ideal but like you say, there are exceptions to the general rule. I think my point is that you might be able to get use out of a 6 but infrequently, whereas you should get much more use out of an 8, so you'd get more of your money's worth out of it.
Personally, I prefer to see the planets at lower magnifications (165-200x) where the object might be smaller but generally more crisp and with more contrast, rather than bigger and blurry, but that's me
Regarding the quality eyepieces, it's not just about the design and manufacturing tolerances that makes them better...it's the quality of glass used, the coatings on the surfaces, the baffling and blackening internally to reduce flares and other reflections... the example I gave of the TV before, it's just a plossl ultimately (and plossls can be great so this is not a negative!) but the TV is one of the better made, if not the best at reasonable cost. Quality eyepieces benefit every telescope, a slow telescope just makes them appear less awful, but the detriment to the image is still being effected.
Have a look out for a Japanese made ortho...simple design, little glass, well made and generally inexpensive for decent brands (Baader, Astro Hutech/UO)...great value for money specifically for planets and lunar. Only downside is the narrow FOV
Regarding the quality eyepieces, it's not just about the design and manufacturing tolerances that makes them better...it's the quality of glass used, the coatings on the surfaces, the baffling and blackening internally to reduce flares and other reflections... the example I gave of the TV before, it's just a plossl ultimately (and plossls can be great so this is not a negative!) but the TV is one of the better made, if not the best at reasonable cost. Quality eyepieces benefit every telescope, a slow telescope just makes them appear less awful, but the detriment to the image is still being effected.
Good point regarding baffling, blackening, and coating quality, the speed of the telescope makes little difference to how important those things are. I was thinking mainly about optical aberrations (number of elements, types of glass used, accuracy of surface figure, accuracy of alignment, etc.) where the speed of the telescope would indeed be a major factor in how much the image was effected. I guess I'm too used to thinking about electronic imaging where you can tolerate some levels of veiling glare and ghosting, I need to remember that for visual observing contrast is king!
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Have a look out for a Japanese made ortho...simple design, little glass, well made and generally inexpensive for decent brands (Baader, Astro Hutech/UO)...great value for money specifically for planets and lunar. Only downside is the narrow FOV
Thanks for the suggestions, I'll definitely look into those.
That's where the attention to detail and QA comes in with the premium eyepieces...for a price of course. You might then be able to see deficiencies or aberrations introduced by your telescope...
Mass market telescopes are manufactured to be 'good enough'...so there's the risk of mirror defects, misalignments, poor blackening of surfaces, etc, etc. They're built to a price, it's the same as everything else.
Then there's the aberrations introduced because of the telescope design. In a fast Newtonian this is usually coma, fast refractors and cassegrains it's field curvature. Your Mak should be coma free but it might be possible to see some field curvature.
If you ask many here, the value of equipment, be it eyepieces, visual aids or whatever, it usually amounts to more than the value of the telescope just feel free to ask folks opinion or experiences...there might be someone in the forum with the same or similar combination