Celestron Nexstar 4SE - Review / First Light

[Astro_Baby]

Last night was first light for my Celestron NexStar 4SE so I thought I’d write a short report / review of the new telescope.

Background

I bought the NexStar 4SE as a small grab and go scope to supplement my Sky-Watcher 200. The Sky-Watcher is a great telescope but its physical weight and bulk when mated with its mount and accessory cases was proving too cumbersome and I found myself missing out on clear nights when I had limited time to spend.

Recently I had transported the SW 200 to a fair few dark sky sites only to find that during set-up or shortly after the weather turned nasty. The time investment in moving such a large telescope and setting it up was quite large and I found my enthusiasm for using it starting to wane. I live in a smallish top floor flat in a heavily light polluted area. Technically a large Newtonian is the wrong kind of scope for that environment but I happen to like Newtonians and accepted its usage may be quite low when I bought it. Put simply its not worth me investing in two hours of disassembly, transport and reassembly for very short viewing times.

I wanted a small, lightweight scope that required minimum set-up times to take advantage of the changeable weather and which could be put out on a site very fast for times when I cant devote a whole evening to stargazing.

Choices

I looked around to see what might be a good choice to fill the requirement. Quite a few telescopes could meet the requirements and I considered a small APO refractor and a small Newtonian. The problem was with the budget I wanted to spend a small APO would mean a very basic mount and even a small Newtonian would take up too much storage space in the flat. I also wanted a telescope that would require minimum maintenance thus ensuring it would be ready to go at a moments notice and would be hardy enough not to require additional cases and baggage. The choice in the end came down to a small Maksutov on the basis of no collimation required, relatively powerful optics for its size, small packaging requiring a simpler mount. The NexStar 4SE fitted the bill rather well as its small enough not to strain a simple Alt-Az GoTo mount. I did briefly toy with the idea of a larger SCT such as the NexStar 6SE but it would have stretched the budget and also been larger than I really wanted. To follow the desire for bigger aperture would have ended up with me owning a CPC 800 and that would present the same transport issues as I was facing with the Sky-Watcher 200.

The NexStar 4SE

Having decided on the NexStar after a longish conversation with the estimable Steve at First Light Optics I paid the money and waited the arrival of the baby sized telescope. I also ordered a dew shield as Maksutovs and SCTs tend to suffer from dewing. I was hoping that with care and attention I would get away without dew heaters as I really wanted the smallest and lightest payload to carry around with the least possible fuss.

In due course the NexStar 4SE arrived. The packaging was immense, far larger than I would have imagined for such a small telescope but reassuring that with so much packaging the scope would survive almost anything the courier could do to it. Inside the three layers of outer packaging was a number of smaller boxes containing the OTA, the tripod, accessories and manuals. When unpackaged and assembled the telescope and its mount looked rather nice in the Celestron house colors of metallic orange. The orange by the way is a kind of burnt colour and not so garish as you may imagine from the advertisng pictures. The telescope came with a standard red dot finder, 25mm Celestron E-Lux Plossl eyepiece, a lead for connecting the telescopes GoTo mount to a PC, some software for using the PC as a controller and a cable for remote triggering of a digital camera. A small bubble level plus a spanner that fits the tripod bolts was also included.

The manual was supplied with a quick start guide and I found all the instructions relatively easy to follow. Set-up time from out of the box was probably around 40 minutes.

By the way if you buy one of these telescope make sure you keep the box that the OTA and GoTo mount head is packed in. It’s a perfect foam filler for the telescope and some after market cases require it if you want professional carry luggage.

I had one small issue which was that the primary mirror when looking down the tube seemed to show a strange patina, almost like an oil film effect on the primary when it was placed under powerful tungsten lights. This worried me a bit as I wondered if the primary may have suffered some kind of coating damage. A quick call to Steve at FLO reassured me. Apparently this effect is a result of one of the coating compounds and can show up under some types of light.

Overall impressions of the unit were very favourable. It uses a fair amount of plastic in its construction but the plastic is very high density and looks very rugged. Fit and finish was perfect, the focuser was a little light for my own personal taste but it works well enough. The mirror flip control is firma and precise and both it and the focuser have substantial rubber grips.

Collimation out of the box appeared spot on. Just as well as these scopes are tough to collimate and usually require a factory return. This shouldn’t happen if they are well cared for.

The red dot finder is a typical low cost unit but well made and perfectly useable. I prefer them in fact to finder scopes myself and on a small scope like the 4SE they are perfectly adequate and much better for beginners to the hobby.

The mount has a built in wedge facility underneath the main head unit which holds the telescope which would be useful for astro-photography although this is outside my own experience. I tested out the GoTo mount in the house and found the motors were relatively quiet and slew at a pretty quick rate.

All of the instructions regarding the GoTo setup were pretty simple and within about 20 minutes of reading and playing around I had alignment using the SkyAlign process ( SkyAlign is a fully automated set up process that allows you to orientate the telescope using just three bright stars to set-up). Something I deduced from playing around with SkyAlign is that you MUST use the red dot finder to locate the stars and not the telescope itself. I suspect that this is because the SkyAlign software is based around naked eye objects. This is perfectly reasonable. The only nuisance factor with set-up I found is that the unit doesn’t keep your time and date settings. A minor problem but the system would have been so much better with some kind of battery backed memory.

I had been advised that although the 4SE mount has a battery compartment for 8x AA batteries its GoTo system is usually erratic with battery power also that it will not function well on rechargeable batteries. I like to test things for myself on this score so I tried a set of new high power rechargeable of 2650maH and found that they worked tolerably well over an hour or so of use with the scope slewing and using its GoTo capability. No problems were encountered doing this but I would imagine from past experience battery life would be quite short especially when the batteries are exposed to cold weather.

As ever when I get a new telescope I learn its functions as well as I can in a well lit room, then I play around with it in a darkened room to get myself familiar with all of the issues of setting it up in pitch black. I find this pays dividends for a telescopes first time out under the canopy of a dark sky.

First Light

After owning the telescope for a week or so I finally got a break in the weather and a free night. The weather tuned very cold and I knew I would have stable seeing conditions. Unfortunately I couldn’t travel as far as I would have liked to a truly dark sky site so I had to use a site which would produce only indifferent conditions. The scope was packed and transported in a single trip down the stairs of my flat and into the car. Along with telescope came a Powertank ( I didn’t want to test the AA batteries out under a dark sky on the scopes first use and introduce any potential additional problems ) and a box of Celestron standard Plossl EPs.

Setup in the dark was relatively easy. Levelling the mount was simple enough using an external bubble level. The one supplied with the telescope is too small to be of any real use. Fitting the GoTo head unit with the telescope was simple enough if a little fiddly but the practice at home as ever paid dividends. Set-up time was probably less than 10 minutes.

I then ran the scope through its SkyAlign procedure and surprisingly it failed twice – then I realised I hadn’t set the date and time and after that it acquired alignment using three stars easily enough. I found on first use the scope was missing its targets by a few degrees but I was happy enough and decided not to bother to rerun the alignment software or to run the procedure for precise alignment.

During the alignment process I took a few minutes out to test collimation with a star and found the scope would produce perfect airy disks thanks to good atmospheric conditions. Unfortunately light pollution although more limited than where I live was very noticeable.

The first target was Polaris as I wanted to assess if the scope was aligned properly and by how much it may be missing its target. It was off by approximately 75% the width of the EP view through the 25mm. Close enough for me to live with so I decided to test the tour mode out….

First up was the Andromeda galaxy - my partner wanted to see Andromeda and its an easy enough target so I punched in the item on the tour menu and the scope slewed across the sky effortlessly and missed Andromeda by a whisker. The Galaxy showed through the 25mm EP as a faint smudge as I would have expected in a scope of this size under average skies.

After having had a good look at Andromeda we moved on. We took a look at a few clusters and the obvious choice of The Pleiades. Most were too large for the field of view of the 25mm EP and it was then I realised I had left the 32mm EP back at home attached to the SW 200 – Doh !!! Personally I suspect even the 32mm may be too limited and perhaps a 40mm may be required to get wide enough views for larger objects.

I then had the GoTo slew us around to look at Albeiro and we could clearly see the double with the golden star complimented by its blue companion. Contrast was not as good as I may have hoped but I suspect this was more to do with the light pollution than any inherent defects in the telescope.

At this point the powertank started to run low – it had been in use for quite some time at home for the previous week and the cold was starting to bite. We decided on having a go for Neptune which was low in the sky but theoretically available. Unfortunately when the GoTo slewed to the position we found a large tree in our line of sight. Unfazed I called up Uranus on the GoTo controller and the scope moved enough to get a view past the tree. It required a little hunting down as the distant planets appear pretty much as dull stars and the GoTo was off by a noticeable margin. By experimenting with a 10mm EP I was able to centre up on the prime suspect in the EP and confirm it was indeed Uranus. This was quite a nice end to the evening as I have never directly observed it before. It showed up as expected as a pale blue point of light.

With the powertank running low and my hands frozen we packed up the telescope and plodded back to the car.

Verdict

Very happy overall and I think I will grow to like this piece of equipment. The GoTo was slightly off but I am sure this was due to some fairly rough and ready alignment and levelling. Running a precise GoTo fix I am sure would have generated better results. The scope was off by a consistent amount each time suggesting that perhaps our time data was slightly wrong. Tracking over the limited time the scope was locked onto each target seemed fine further reinforcing my view that errors in the GoTo were most likely induced by a sloppy set-up.

The scope performed very well over the course of perhaps 90-120 minutes actual use and I am sure with a bit of perseverance and having the wider angle EP it would produce the visual goodies. The views of course are never going to equal the Sky-Watcher 200 which by virtue of its larger aperture and faster f ratio is more suited to deep sky targets but I feel the NexStar was a good buy as a grab and go unit. The optics seemed perfectly good to me for its small size.

Under a less light polluted environment I am sure it would return better views and based on the first nights viewing I am sure against targets more suited to its design it will excel. I’ll add some more reviews of it when I get a chance to use it on some more varied targets.

It’s a perfect complement to the larger scope offering near instant set-up and reasonable views given its tiny size.

[EA2007]

Nice review,

you'll find that the alignment issue is solved via a healthy set-up procedure, perhaps bettered if you perform a EQ North Wedge align but this takes a little longer than the 3 star Alt-Az align.

I agree that the supplied bubble level is quite lame. And the field of view is quite limited, but expected from the quite high f/12 value.

[AllanJ]

Thanks for a good clear review. If the GOTO alignment doesn't take you exactly to your target, then once you home in on the target the Sync function is very useful for keeping it centred.

Allan

[EA2007]

You could always use the guideport function, I never got round to using it on mine when I had it, so can't really advise on its performance.

There may be some issues with that option though, if you have an guideimager on the NexStar then you can't use the flip mirror to view at the same time, also if you want to use a guideimager on a second scope then the plastic fork arm and motors might not be strong enough to cope with the added weight.

Play around, you'll get it sorted, its a nice clear nigh tonight (albeit cold)

[ringz]

Mel,

Here's a couple of tips for aligning the scope to increase goto accuracy.

Firstly, if you haven't got a reticule eyepiece to centre your selected object, defocus the scope so that the object becomes a large as possible because an extended circle is much easier to centre by eye.

Secondly, make a note of the direction the scope approaches objects; that is look, through the eyepiece, when the scope is doing it's final manoeuvre. Make a note which direction keys produce the same motion in the eyepiece and then use those keys to do your final approach to alignment objects.

It does make quite a significant difference to accuracy.

--

Martyn.

[Astro_Baby]

Going forward I'll probably do a proper three star align with a decent watch that keeps time - I think the one we had last night was off by about 30 minutes at least :? - probably worth me wearing my Baby-G sports watch in future

[Tiny]

Nice report - it seems an ideal grab and go scope.

Silly question. Why does the scope have to be leveled. It aligns using the stars.

[EA2007]

Your correct Tiny, it does align with the stars, but the mount needs to be level because the onboard computer needs all the correct parameters to allow it to locate things after the setup, one paramter being a level mount.

If you go through the setup procedure with the scope at an odd angle (not levelled) then it will think that it is in a different location, when you want to find something, thus using the goto function, it will not locate the object.

[Doc]

Mel that was an extremely well written and detailed report. A must read for anyone who wishes to buy one of these telescopes.

Sounds a great grab and go scope.

Hope it gets loads of use.

[ChrisEdu]

Glad to see you've finally got out and used the scope. Jupiter looks pretty good through it, you should be able to make out some banding.

[EA2007]

and the moons.......all 4 medici's if your lucky!

[ChrisEdu]

Indeed - I saw three moons when I viewed.

[tarqs101]

Really interesting review Mel,

as you know my family were buyin me a scope for my big birthday! Well turns out it's a Nexstar 102SLT short tube refractor. So was really interested in reading about the mount and GoTo. Obviously the optics on mine won't be quite as good as your Mak, but hey, it's a million times better than what I have!

Gavin

[brendant]

Excellent first light report Mel.

Hope the scope brings many nights of enjoyment, as you have highlighted whilst big scope are great there is no substitute for a small instrument for grab and go. The best scope at the end of the day is the one you use most.

Brendan

[ChrisEdu]

... there is no substitute for a small instrument for grab and go.

Ooer!

[Deacon]

Hey Astrobaby,

Great review. I have a skywatcher refractor 100 Pro with an HEQ5 mount and it's quite time consuming to set up as well as quite physical expecially after I have finished a shift (work as a staff nurse). I have been looking to get a grab and go scope. The Skywatcher Skymax 102 SynScan AZ GOTO looks good too!!

Deacon

[Astro_Baby]

I think if I were buying today I'd more likely get the Sky-Watcher 127 SkyMax on the Alt-Az GoTo mount.

A short refractor would also be a good one to get for widefield. I wanted the smalles reasonable package cos the Nexstar will be travelling to the Indian Ocean this year - with some luck

[philsail1]

Excellent comprehensive and well written first light report "Astrobaby."

Re levelling the mount. I don't know if it is possible with the Celestron you have, but I've heard that it can be useful to put a level across the top of the mount to ensure that it is indeed as level as you can get it.

I have a Celestron CG5 "GoTo" mount and I use the method, to double check that the mount's own built in bubble level is accurate - thankfully it is!

Best wishes,

philsail1

[Stardust]

Great review and will assist anyone thinking of getting one of these scopes. I nearly did some months ago but the money went somewhere else in the end.

With the dove tail mount your could always get a small refractor and swap the tubes over.

[cparker5]

I purchased one of these last night at a Ritz Camera that is going out of business for $220. I am very please with the deal I got and the post-purchase research I have done.

I am looking forward to getting my Nikon SLR attatched to this and get some pictures.

Thanks for the well written review and the follow up posts!

[Astro_Baby]

ONE YEAR ON

I thought I'd write a review one year on. After all during a first light review there’s a natural 'buzz' to the product which a year later is missing allowing possibly a more objective view of the product.

Last week the Nexstar 4SE was dragged out from under the bed and used again. During its tenure as my 2nd scope and my grab and go device its been used rather little. In fact the 8" Sky-Watcher has seen more use.

At the Salisbury Star Party in August 2009 I had the Nexstar with me but for some reason the alignment process kept failing. I have no idea why but I suspect the software was defective in some way. In part I never investigated at the SSP in August because the sky was suffering clouds and I wanted time to use the 8". The Nexstar 4SE just sat there mournfully and got coated with dew.

Last week the scope was dragged out and I gave it the treat of a software update. The Celestron software update system is tough to find on Celestrons site but I eventually got there. Software updating for one of these things is a torturous process I found and takes ages. None the less once updated I determined to test the scope out again at the first opportunity.

Now I should say at this point that the 4SE has been used quite a few times and before the SSP bash it had always acquired a fairly accurate alignment.

So last week the scope was taken to Newlands Corner which is a nice(ish) site to work from and set up.

Skyscan Grief ( or not )

Initially the scope proved a pain to work with. The power lead tended to keep dropping power despite me having opened up the DC power centre pin on the scope. For those not in the know the Nexstar series all seem to have a problem with the centre pin on their power jack. Its too narrow for many 2.1mm jacks and as a consequence reliable power can be a problem unless you use a small jewellers screwdriver to open out the centre pin. This had been done but the 4SE still gypped up.

The fault was eventually traced to a faulty jack plug (grrrrrrr ) Sorry Celestron wasn’t your fault after all.

After the flakey power was resolved the Nexstar hit alignment first time every time and both located objects easily and showed very little in the way of tracking errors. Though the Skyscan software can report objects as visible when in fact they are below the horizon.

Tracking was accurate enough that when M42 disappeared behind a cloud and I decided to warm up in the car for 20 minutes when I came back out and the cloud had pushed off M42 was still pretty close to centred.

Most targets fell into the view of a 40mm Plossl EP and a 25mm Plossl both were in use.

I have seen a review of the Nexstar castigating its inability to find objects and its wobbly mount. I can only report as I find. Apart from the SSP bash the Nexstar has always been as good as gold. Its alignment routines have worked perfectly (if a little slowly due to its relatively slow slew speed - slow compared to a tuned up HEQ5 that is). Its tracking has usually been very reliable and the solidity of the mount adequate.

The 4SE View

I have read on some reviews moaning about the Nexstar for its poor quality views. I find this strange and can only imagine that people are expecting too much from a 4" Mak with a long focal length. I have always found the 4SE to be rather good at planets, doubles and bright objects generally. It’s not a good performer on DSOs.

I have viewed the Moon with the 4SE and found it to be good, it makes Albireo beautiful with clear colour and sharp views and generally provided good views of Jupiter.

One of my small bitches with the 4SE is the lack of 'feel' in the focuser. I reported on this when I first reviewed the scope over 12 months ago and it’s the one thing I really dislike with the scope. With that said I have tried out a few other small Maks and found them all pretty much the same in this regard. Including a Vixen equivalent which is a good deal more expensive.

M42 looked good in the scope with a 25mm Plossl. M45 and many open clusters needs a wide angle EP of around 40mm and even that proves too narrow at times. I have noticed a marked disposition with wide angle Plossls when used with this scope to go a bit large on the Kidney Bean effect. I can’t say whether this is a problem bought on because of the Maks narrow field and high F-number.

Overall - too orangey for crows perhaps

Would I still buy it today if I were buying again. I think if my needs were the same then yes. For a small Grab and Go scope its worthy of consideration. Since I bought the Nexstar 4SE however other scopes have come along. The new SkyWatcher GoTos for instance. These offer more aperture as well as Goto for the same money.

If I were buying now I’d look to the Skymax 127 on a GoTo as its more or less the same price but with that said the Celestron is a nice scope and has a slightly more stylish look about it. There’s something about that orange tube which calls deeply to some of us.

[oceanheadted]

Mel,

thanks for the update. It's good to hear a considered opinion on a piece of equipment after a long time living with it,

cheers

Alan

[Ogri]

Thank you for that review, it was really helpful.

Seems I have got the bug after all (laughs).

[lulu57]

If I were buying now I’d look to the Skymax 127 on a GoTo as its more or less the same price but with that said the Celestron is a nice scope and has a slightly more stylish look about it. There’s something about that orange tube which calls deeply to some of us.

I would agree.

Even though I later got the 8se, I still keep the 4se for trips further afield - it's really easy to cart about, whereas the 8se is not (for a wuss like me).

I took the 4se to France and saw some super views of Jupiter. And I still managed to pack clothes and make up for me and Nicnac for a whole week! (That's going some! Couldn't have done that with the 8se).

And it is indeed very, very pretty.

[Jim M]

There’s something about that orange tube which calls deeply to some of us.

I'd bet your preference of the orange over a blue tube is linked with some experiences you may have had in the 60's or 70's!

Oranges (and browns and purples) were very prevalent colours in those days on wallpaper, lamp shades, setee's etc You should see my desktop! LOL - brown and orange themed. Ahhh.... those were the days. :-)