on 9 February 2014
Apologies for length of this review, but based on 4 months solid use and all we have experienced.
This model was purchased at Christmas as a first telescope for complete novices, largely on the strength of the computer governed motorised Go To function and the good size of the mirror at just over 5 inches. The Go To makes it easier to locate objects, and the size of the mirror means that faint objects well beyond the capacity of the naked eye can be seen. It also provides some basic detail of the the planet Jupiter.
The kit arrives with everything you need bar batteries to power the motors (8 AAs not supplied). No complex assembly of parts is needed. The tripod folds out and a plastic tray for odds and ends sits between the three legs, also providing some bracing of the legs. The motor and telescope support arm has some weight but is easily managed, locating on the top of the tripod and secured by screwing up a large plastic nut by hand under the tripod head. The optical tube assembly, OTA, slides into a place locating a metal bar in a dovetail fixing on the support arm. It is secured by tightening a nut by hand, though the OTA needs to be cupped in the arms underneath to lift it fully in place to get the nut tight enough to take out slack and make the connection solid, which is essential. Not the best of design but it works ok with some patience. Once fixed you probably won't have to undo it again. The direction finder slides into a dovetail on the OTA. This is a good design. It contains no lenses. A red LED (not laser so safe to look at) shines against a piece of glass in the finder as a dot with adjustable brightness. The telescope is moved until the red dot is directly over the object of interest. In theory it should then be in the middle of the field of view of the telescope but the finder will more than likely need to be aligned. It is easier to point the telescope during the day at something like a distant chimney, centring the object in the telescope viewfinder by eye and then aligning the finder to match. Two thumb screws shift the pointing direction of the finder left/right and up/down if necessary. In our case there was insufficient travel on the left right adjuster and this required undoing the screws fixing the finder to the OTA with a pozi screwdriver until JUST loose (there are nuts inside the OTA which you don't want to come off and hit the mirror). Then shift the finder. The optics all need to be lined up and should come perfect in the box. They are tested by looking out of focus at any star. You should see perfectly circular haloes. Luckily we did. If not, the telescope needs to be 'collimated', requiring a tool not supplied - see You tube videos.
The eyepiece holder fits in the focuser tube and has an adapter to take 2inch eyepieces (which is useful but unlikely to be needed, most eyepieces and accessories at this level being 1.25 inches in diameter). The focuser is ready assembled and an eyepiece is inserted in the tube and two thumb screws tightened to hold it in place. Primitive but seemingly a universal means of fixing whatever you pay for a telescope. The controller hand set plugs in a clearly marked socket. There is another socket for a mains adapter (not supplied) or a separate rechargeable 12v battery pack, a so called "tank" available for around £55 incorporating a torch. The scope will move up and down by hand but not turn sideways without the motor on so power is an essential. Batteries don't last long so are expensive. We found we had an AC/DC adapter on some other equipment providing 12 volts DC at a sufficient max current (2amps is fine) and we used that with an extension lead in the garden. You soon realise though that you need to fork out for the portable battery tank for practical and safety reasons.
The big selling point of the scope is the Go To function and there are a number of options for using this. The general approach is to point the telescope at a star or stars (planets can also be used), using the motor to move the scope to another star. The more names of stars you know the quicker it all is but if you know none at all it's fine. The telescope needs to be pointed at three objects in succession reasonably well spaced in the sky and at different altitudes. The computer should then work out how it is aligned and then will go automatically to any of the objects in its database just by selecting them on the handset. We got this alignment to work on the second attempt but it is not foolproof. You need to enter the time on the handset accurate to the second preferably before you start. It is rather annoying that the handset does not have a clock built in so this needs to be done every time the scope is switched on. You also need to enter your latitude and longitude but getting this spot on is not so essential. You can also use the pre programmed locations in the handset though there are only four or five for the UK. In our case London is good enough though we are 25 miles from the centre. But it is simple enough to put your post code in the internet or consult a sat nav to get the
required figures accurately. It only needs to be done once and the handset retains the info. The scope will also track objects once set up so they are kept in the field of view with little adjustment using the hand set.
So on to using the scope! What do you see. Forget the Hubble telescope pictures. Using the supplied 9 mm eyepiece (72times magnification) you will be easily able to see four moons of Jupiter as dots, and on a good viewing day, two weather bands as stripes on the surface of the planet showing as a small disk. It is possible to see galaxies as white smudges, very hard to find without the Go To so it comes into its own. The bigger star clusters and nebulae are the forte of this telescope and one can spend ages staring at them. The moon craters will have you going "wow" too.
Two issues are relevant. One. The supplied eyepieces are very budget and while it is not essential it seems pointless to buy a telescope at this price and optical quality and not use its full potential. In other words be prepared to spend another £100 or more to get some good eyepieces. You can pay over £500 each ! but we chose the Celestron x-cel lx at around £65 each, which we find are very good, being brighter with better contrast and giving a much wider field of view that makes viewing far less tiring not having to squint. These lenses give real wow moments when you first view say the nebula in Orion M42 (dial it up in the handset to get there) or the Pleiades. Two. The focuser has to be the worst piece of engineering ever, hence four stars and if it was a separate item two stars. Shame on Celestron. The tube with the eyepiece moves on a gear rack to focus and has enormous play. The mechanism is lubricated with very viscous gunk that makes it hard to turn the focusing knob. We find it is best to focus by turning the knob quite quickly from out of focus through focus to out of focus again and then coming half way back to get pin point sharpness. This is undoubtedly an acquired skill but made much harder by the cheap engineering. Some adjustment is possible, not described in the hand book (which is generally useful and in proper english if somehow rather old fashioned - download off the Celestron site to get more insight about using the scope before purchase). Two small set screws sit either side of the focuser locking screw and can be tightened using a small Allen key. This gets rid of most of the play but you have only to use a proper two speed focuser to realise just how poor the one on the 130 is. But don't let this put you off at all. Of course you expect better at the price, but again focusing is an art worth developing as for one thing, touch the focuser and the magnified image in the eyepiece will dance about regardless of how good the focuser is. You can of course easily pay £5000 for a sturdy mount! Make the adjustments to the focuser and take the design limitations as part of the fun.
Thirdly, be prepared that the Go To is generally a bit out due to the gears and motor as well as any errors in setting up. Use the low power 24mm eyepiece first to check where you are. This may sound frustrating but you rapidly discover that a big part of the fun is hunting the objects and developing the skills to see faint things.
Can you take photos of what you see. £25 will get you a clamp to fix any holiday snaps point and shoot digital camera to your eyepiece and it works remarkably well though. Use the self timer to avoid shake when you press the shutter button. Fiddly to set up but download free software like GIMP (free photoshop equivalent) to bring up the levels and what looks like three white dots turns into a nebula. We also bought a very modest CMOS webcam and using the supplied software produced a very detailed photo of Jupiter including red spot after half a dozen attempts and observing sessions in the back garden. If you have a DSLR you can take off the lens and connect to the telescope using connectors for around £20 and take some remarkable long exposure shots, though you are limited by the mount that results in objects turning in the field of view due to the rotation of the earth. (An equatorial mount is needed and the 130 slt cannot be easily adapted).
In conclusion, use the vast resources of the internet to find out what to see each month. You Tube videos are a really useful source of information and expertise not least on astro photography. We were able to see the supernova that had emerged the previous week in M82 and which is gone in a few more weeks. These happen at a rate of about once every thirty years per galaxy so you can be party to some special events with this equipment. This telescope isn't the best of course and it could be better. But it has excellent optics and the ability to put you in awe of the universe. Prepare to spend more money to maximise the initial investment. Observing as a family is great fun - let me have a look, let me have a look! This telescope is recognised as a very good one and no one would think you had wasted your money on it. If you decide to join a club first and see whether you get the bug, if you did, almost certainly you would end up saving up and paying two or three times the cost of this kit, but in the end it might be cheaper. Highly recommended, strangely as much for the flaws which add a challenge, as for the good.
I have now moved on to using a DSLR and you can get good results, see M81/M82 galaxies image
on 18 October 2009
I recently purchased the Celestron Nexstar 130SLT and I am more than happy with my purchase! The quality of the scope and mount is excellent and the 'go-to SkyALign' mount is a breeze to set up; simply input your local time, date etc.. and aim the 'starpointer' at any three bright stars or objects in the sky (even the moon can be used for this)and thats it!! This worked first time for me and I was using the 'tour' feature within minutes! The on-board computer has thousands of sky objects in its database and is a marvelous feature.
The two lenses that come with the scope are of a good quality especially the 9mm eyepiece. I would however recommend investing at some point in the Celestron eyepiece kit which has several better quality lenses as well as a Barlow x2 and several colour filters and a Moon filter, however the two eyepieces that come included here are more than adequate to start off with.
on 18 May 2009
I've wanted a telescope for the past decade, and I recently decided that it was now time to splash out and buy one so that my children (oldest is 6 years) could explore the Moon and planets with me. When it comes to astronomy and telescopes I am a complete novice and so I did a lot of research before settling upon the Celestron Nexstar 102 SLT. Here is what I have learned...
Firstly, a telescope is like a mechanical eye that collects light and focuses it onto an eyepiece. The bigger the aperture of the telescope, the more light it can collect and the fainter the objects it can see - so big is good. Imagine that in the dark, the pupil in your eye has a diameter of 5mm that allows light into your eye where it is focused by a lens. That means your pupil has a surface area of almost 2 square cm to gather light. The Nexstar 102 has an aperture with a diameter of 102mm, giving its lens a surface area of over 800 square cm - meaning that it can focus over 41,000% more light onto its eyepiece than you can with your naked eye. This means that it can gather light from very faint sources, such as distant stars and galaxies.
Secondly there are two main types of telescope, reflectors and refractors. Reflectors use a curved mirror to bounce the collected light into an eyepiece, whereas refractors use a glass lens. Generally mirrors are cheaper than lenses, are not so heavy and can be made bigger (remember, big is good) but mechanically reflectors are more fragile than refractors and need regular calibration (called "collimation"), whereas refractors are more robust. So reflectors and children might not mix as well as refractors and children. The Celestron Nexstar 102 SLT is a refractor.
Next, I wondered what I would do with a telescope once I had bought one. Being a novice, I can't read star maps, so being able to pick out anything in the night sky with the exception of the Moon is simply wishful thinking! And pointing a telescope at an interesting looking object, whilst telling my children that I had no idea what it was that I was showing them, was not the educational experience that I was intending. So, the third thing that I learned was that I needed to buy a "go to" scope, that would point itself at objects of interest in the sky and tell me about them. The Celestron Nexstar 102 SLT does exactly that, and only requires a very simple alignment routine that even I can do. The computer keypad even has a "tour" button, which will automatically point the telescope at items of interest and then tell you all about them. Very clever. And it will also track objects through the sky, keeping them central in the eyepiece automatically. This is very useful, and you might be surprised to see how quickly the Earth's rotation causes an object to move out of view when this feature is turned off.
The last thing I needed was a telescope that would allow me to take photographs. The Celestron Nexstar 102 SLT has many optional extras, one of which allows the connection of a digital camera. Great.
One important thing that I learned is that you can spend as much money as you like on equipment, and so I set myself a budget of £250 (telescopeplanet were selling the Celestron Nexstar 102 SLT for £249). On the negative side, there are very few things to really call out as criticisms, given the (budget) price of this telescope, but... this is a lightweight telescope (it has to be I suppose, because it is motor driven) which takes a few seconds to stop wobbling if it gets knocked; the "enter" key and "up arrow" on the keypad are very close together; and manually driving the scope to an object is not intuitive to the novice. But these are minor irritants.
All things considered, this is an excellent first class educational telescope that is ideal for the beginner, amateur and interested child. It has features that I'm sure would have only been found on professional telescopes only 10 or 20 years ago, and I am sure that it will give me and my children decades of viewing pleasure.
on 4 September 2010
I think this is a great little telescope. I recently sold my C6-SGT as there's not much room in my house and I was tired of stubbing my toe on it, so I thought something less-heavy and occupying less floor space would be just the ticket. So I bought a Celestron 127 SLT.
Coming down from a C6, I thought there would be a significant trade-off in optical quality, both in terms of power, resolution and light grab, but it isn't immediately apparent, with bright, clear viewing. All my long eye relief eyepieces work well with it, and I don't need to use the 9mm and 25mm plossls that come with it, though there is nothing wrong with them. Through a Celestron 5mm X-cel, the banding and red spot on Jupiter are both easily discernible I'm happy to say that the little 127mm Maksutov copes very well, with excellent resolution and contrast. If the optical tube has been built down to a price then it isn't immediately noticeable and can easily cope with 300x. I really can't find fault with it optically; this is one powerful little telescope.
Celestron goto system is great and easy to use. Takes about 2 minutes to set the telescope up ready for viewing
The tripod, however, is a different matter. This telescope deserves something a little more sturdy, even if it added £50 to the price. Only other bugbear is the rear thread on which the eyepiece assemble is mounted. The thread is too small to accommodate my focal reducers and I can't seem to find any that fit on the internet. Hence, the 127 SLT is best used for planetary work. If galaxies and star clusters are your thing, then something with a shorter focal length might suit you better.
on 6 January 2010
I spent around 6 months investigating which telescope to get, I had pretty much settled on this one or the equivalent product by skywatcher. After this telescope got the Sky at Night Magazines best beginners scope in 2009 I desided to go with this one.
Although this is a goto scope and setting up is fully automated, occasionally it doesnt work and then having an idea of your constellations is helpfully. Sometimes I am better at working out what the scope is pointing at and use one of the less advanced alignment modes.
I also use the optional extra RS232 cable nd hook it up to my PC, this allows me to create tours of objects the to view the day before and then control everything form the PC rather than the handset. I also find an ipod or other mobile device running a star guide program most useful.
I went for the 102mm refractor rather than the similar priced 130mm reflector because I wanted to take pictures and because refractors are less hassle to maintain. Although as the mount is not an equatorial type it wont track as well for longer exposure photographs.
For the price and ease of use as a first telescope I give this product 5 stars. A more advanced user would want a more expensive mount and scope but that would cost much more.
on 19 February 2011
Awesome telescope definitely worth every penny. Managed to observe saturn clearly and moon surface detail can't wait till there's more in the night sky later this year. If I was to criticise though I'd have to say that the batteries do go pretty quick and seeing as it requires 8 double a's it can be expensive! There is a 12v plug input though (not included) (and nor were the batteries : ) ). All in all I would recommend the 90 slt to any novice willing to throw some money at a new scope and wanting to see more in the night sky.
on 6 October 2012
Fantastic telescope, if you are prepared to have patience in learning how to use it. Using such a high-power telescope isn't easy and it can be hard to get good, clear viewing.
The GoTo calibration isn't always accurate and it might take 2 or 3 attempts to get the telescope aligned before you can start using it. It's important to set the time correctly and to make sure the tripod is absolutely level before you begin. There's a spirit level for this purpose, but you have to be spot-on. Once aligned, the GoTo functionality is easy to use.
I almost regret getting a GoTo telescope because I haven't actually learnt all that much about astronomy (although I have had fun). With a manual telescope I would probably have learnt more, but used it less - swings and roundabouts!
The telescope takes 8 AA batteries and runs them flat in a couple of hours, especially if it's cold. Rechargeable AA batteries don't work well because of the lower voltage, so you do need to invest in good alkaline batteries. Alternatively, the telescope has a DC power socket so you can use an external power source. You could hook it up to a 12V lead-acid leisure battery which will keep it running for many observation sessions, or if you plan to use it in your garden, you can use a 12V DC transformer and an extension lead. Make sure to check the maximum current rating because the telescope is quite demanding.
Optically, this Cassegrain-Maksutov telescope is better suited to planetary viewing. If you want to look at galaxies, nebulae and other DSOs, you would be better off choosing a Newtonian formula telescope such as the SLT 130. Newtonians have lower magnification but better light-collecting ability.
You can easily get a T-mount for this telescope and attach a digital SLR camera in place an eyepiece for excellent astrophotography. The motors in the mount seem happy enough with a reasonably heavy camera piggybacking on the telescope.
Do take note that this telescope has an altazimuth mount, rather than an equatorial mount. This means that throughout the course of the night, the field of view shown in the telescope will rotate. Bear this in mind if you are taking long exposures for astrophotography. An equatorial mount is the "real deal" for astrophotography.
I probably wouldn't recommend this telescope to a complete beginner, but it's excellent for a second telescope after you've learnt the basics on something a bit smaller.
on 14 January 2013
Be aware when you buy a refractor that there will be chromatic aberration, i already knew this so no complaints,
tripod could be more stable a lot of vibration, recommend an external power source as it takes 8 batteries, there
are extra items you can buy to improve it especially a Baader fringe killer filter. When the vibration dies down and it's focussed correctly the views through it are great, i saw the bands on Jupiter and the Orion nebula within 5 minutes of set up. The computer controls are quite intuitive but i would recommend having a trial run in daylight with the instruction manual just to save time. I bought a refractor because they are pretty robust and easy to transport, i think it's great i absolutely love it, if you intend astrophotography however i would go for a reflector type which tend not to suffer from chromatic aberration.
on 17 October 2015
This is my first decent telescope so needless to say I had great expectations, having watched Venus, Jupiter and Mars outside my window every morning for the last few weeks I was really excited to get a closer look with my new telescope, as those aren't visible to me till around 5am I went out around 2am for some practice on some stars and maybe a few things that the finder could show me.
Getting the scope setup and aligned was fairly easy so I was filled with confidence and excitement this is where my story peaked, from here on it was more or less downhill. Looking at a few of the brighter stars it was hard to tell if they were any more visible than they were with the naked eye, basically just tiny white dots maybe a millimetre in diameter with no detail but they are pretty far away, so I moved on to letting the scope show me some nebulas or deep sky objects, at this point I should mention that I didn't have complete darkness as I was in my garden so there was slight light pollution, but I still expected to see something, anything, but I saw nothing. I persevered for an hour or so with similar results.
When 5am rolled around I went back out hoping that I'd have better luck with some planets, firstly I tried Venus which is very visible to the naked eye, all I saw was a bright white shape that wasn't even circular maybe 2mm in diameter, so I moved on to Mars which was another bust, my final hope was Jupiter, it's massive surely I'd see more here? At this point I find myself questioning the purpose of this telescope or if it's broken as Jupiter is maybe 3mm in diameter, if I really strain my eye I think I can maybe see a band around the middle but this could also be wishful thinking and my brain trying to justify the £330 I spent on this telescope.
I've read all the reviews on here it's the reason I bought this telescope, but I'm having a completely different experience so far. I did note that some of the people who'd reviewed it had bought other eyepieces and stuff which I've now also ordered, but this review is for the telescope minus any other stuff you have to buy, and to be honest I'm not sure it's worth the money. Also Celestron have been pretty tight with the supplied equipment, at £330 they could have thrown in a power supply and the cable to update the handset.
I'll come back and update this when my other eyepieces arrive.
Update: I probably should have waited a bit before posting my review, but to be fair the early disappointment is something people should be prepared for, this isn't Hubble and most things are going to look tiny. With that said I've now received my Barlow lens and had a chance to look at the moon, and despite cloudy conditions I also managed to get a really good look at Jupiter, it was still fairly small maybe 4 or 5mm across, but I could see the colour bands and also managed to pick out 4 of Jupiter's moons which gave me a definite wow moment. I've also ordered a Celestron X-Cel LX 18mm on the strength of someone's review for this telescope, it should arrive today or tomorrow so will update again when it does. I'd now be willing to recommend this telescope but with the caveat that you should be prepared to spend more money as the provided eyepieces aren't the greatest, but as a starter point it's pretty decent.
The attached picture was taken using an Celestron X-Cel LX 18mm a lunar filter and my iPhone 6s held freehand above the lens.
on 16 August 2013
- Very portable, easy to setup. You will probably get to use it more than larger telescopes.
- Great at planets. Couple it with an inexpensive webcam and process through Registax and you will get impressive photos of Saturn, Jupiter etc
- Not well-suited for deep space objects. I upgraded from a smaller newtonian and I was underwhelmed by the DSO views. There is a way to fit an (expensive) f/6.3 reducer, however the thin 1.25" barrel limits your field of view, so the reducer is not really a solution.
- Not sturdy enough tripod gives a lot of vibrations (when you touch the focuser, when the wind blows etc) See tips.
So, overall, this is a very easy to set up and use scope that is great for viewing and even photographing the moon, sun (with a filter) and planets. If you have looked through a wide-field telescope the deep space object performance will probably disappoint. I would say this is a great telescope for an urban location, as the GOTO will be useful when there are few stars visible to use as pointing guides and also planets are anyway the best targets when there is light pollution.
- The Celestron Vibration Pads are a good investment, halving the vibration if you are setting up on a hard surface. When using the vibration pads you can also try putting some weight on the accessory tray.
- A good and inexpensive choice for an eyepiece that will improve your planetary viewing is the skywatcher Ultra Wide Angle 6mm. It provides 250x (which is usable more often than not - depending on seeing conditions), a generous field of view and eye relief.
- An illuminated reticle / crosshair eyepiece will make the initial alignment easier/faster.
- Don't even try the batteries. Get an AC adapter. A generic will do, although I have to use a rubber band on the arm of the mount and pass the cable through it before plugging it in so that the cable is not pulled when the telescope is moving around (the Celestron AC adapter screws on).
- Get a solar filter and it will give you something to do with your telescope during the day! The least expensive solution is to get the Baader solar film and create your own cardboard holder (instructions are widely available).
I am attaching a photo of Jupiter shot through the movie-crop mode of a Canon 550D, just for an idea.