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nexstar 4se good or rubbish

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nexstar 4se good or rubbish

Postby neil0748 » Thu Apr 30, 2009 8:30 pm

Iv'e got a nexstar 4se where am i going wrong people on here are getting better planet pics than me and they are using cheaper scopes is the skywatcher 250PX better than the 4se if not im going wrong some where ?
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RE: nexstar 4se good or rubbish

Postby uea74 » Thu Apr 30, 2009 9:03 pm

Seems an odd comparison:
The 250PX is, as it says, 250mm dia, the 4SE is just 102. So the 250 has about 6.25 as much light gathering power, and that is not allowing for the losses in the optical path. I suspect that the 4SE will lose a greater percentage of the light then the 250PX will.

Additionally the 4SE has a focal length of 1325mm. Whereas the 250PX is less at 1000mm, a much better f number for imaging.

As to cost the 4SE seems the cheaper at £370, the OTA for the 250PX is £420. On top of that for imaging you would need a good mount and motors to drive it, say another £250. So to image with the 250PX seems to come out at about £670.

The Celestron price is for the electronics and goto that it has.

People oftan use the 4SE as it is a goto and easily transportable. Take it to some nice dark place or a meeting, set it up, do the alignment then let it do the work of going to the right area of the sky.
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RE: nexstar 4se good or rubbish

Postby neil0748 » Thu Apr 30, 2009 9:20 pm

thanks for the info uea74 look's like i will have to save my pennies for a skywatcher. The problem with the 4se is the focusing. You know what they say you get what you pay for which i did'nt.
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RE: nexstar 4se good or rubbish

Postby astro_baby » Thu Apr 30, 2009 10:43 pm

Hmmmm - I have a 4SE as a grab and go scope and its fine. The focusing is a bit overlight for my taste but its acceptable. It is a small scope though and a Maksutov at that so it has relatively small light gathering and a long focal length. Its good againts planets and bright objects - less so against faint DSOs - Andromeda for instance looks very tiny in the 4SE.

I have a Sky-Watcher 200P as my main scope on an HEQ5 Pro which undeniably gives far better views of DSOs (although its planetary performance is broadly similar ) the 200P is powerful and with the addition of the Moonlite Focuser and half decent EPs it provides some great views.

Its hardly a fair comparison as my 200P even in its base form would be 2.5x the price of a Nexstar 4SE. A 250PX would cost even more. Bearing in mond the 250PX really needs an EQ6 that would put a non GoTo version at around £1,100 or £1,400 with GoTo which would be 3.5x the price of the humble Nexstar.

Theres nothng wrong with the Nexstar but it is a small telescope. This is one of the great hassles I think for beginners who go the GoTo route. It can mean with a budget that all of the money goes into the electronics rather than the aperture. As a result you can end up with the technical wizadry to find 30 zillion objects but have enough aperture to see only a tiny percentage of them.

With all that said - get the Nexstar 4 out to a dark sky site and you will definitely be able to some good stuff. I found Neptune with mine which I had never seen before and while it appears only as a small blue blob the fact I could see it at all was rather wonderful.
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RE: nexstar 4se good or rubbish

Postby uea74 » Fri May 01, 2009 11:10 pm

I don't have a Celestron but wonder if it is set up OK or if it could be improved. Do they need collimating?

Did look at getting one but the aperture is small and the loss through the system will reduce the effective aperture even more. I think the secondary mirror takes out 12% and there is god knows what inside to block stray light that also knocks out some of the light you do want. I stuck with the small Meade I have. Then it has a long focal length for its aperture. So overall I guess that the 4SE was never really intended for imaging.

Sticking a camera on would prove an effort for the motors.

I think we have to be realistic about scopes, read what people say they want their first scope to do and it is nearly always, view the planets, stars, nebulae, every DSO and image also. Additionally nice if it were a goto while they learn their way round the sky. The images also have to match those of hubble or preferably a bit better.

I would say find out if the 4SE can be set up to perform better and get used to it. It should be a good little scope to take out and view through but don't expect hubble like results. And for viewing I would say stick with eyepieces of 10mm or more as I guess that anything less will be too much for the scope, that would give 130x magnification, even that may be a bit much.
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RE: nexstar 4se good or rubbish

Postby astro_baby » Fri May 01, 2009 11:43 pm

Well the 4SE is a mak. Technically they shouldnt need collimating unless they suffer a major disaster. In any event the 4SE has a recomendation in the manual to leave collimation alone and return to the factory if it needs it.

I'm pretty dab handed at collimation but the 4SE would scare the hell out of me because to collimate it you basically have to take the entire back of the scope off which of course means the focuser as well. Then you have to tweak it, reassamble it and retest. The chances you;d get it right are negliigable so you;d be taking the back off and putting it back on again for testing a few dozen times. Even standard SCTs can be swinish and the best advice out there where Maks are concerned is leave them alon unless you have some serious time on your hands and have the risght test equipment to do the job poperly.

I tested mine on its arrival and it was fine, star testing also shows it to be ok.

uea74 - you say beginners all want to look at everything plus image - you forgot most of them also set an unrealistic budget of say £300.
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RE: nexstar 4se good or rubbish

Postby northerncross » Sat May 02, 2009 1:06 am

[quote]you say beginners all want to look at everything plus image - you forgot most of them also set an unrealistic budget of say £300.[/quote]

Astro_Baby - I think you've hit the nail right on the head with this one!

I've recently bought a Celestron 4se (£370) but not had an opportunity to put it through it's paces as yet, so am unable to comment much.
Trouble is, each manufacturer is trying to sell their products, with all sorts of hype about what it will do, so as a beginner, puts you in a quandry as to which one is the right one! On buying my celestron, I asked 'will I be able to see Saturn with this?' answer - of course. Stupid me! What I should have asked is what sort of view of Saturn can I expect from this. Not only that, but I was just a little surprised to find that you can manually move the scope upwards and downwards, but have to use the motor-drive to slew left and right

Does anyone think that maybe we should start a section on the forum of users reviews about the scopes they have used / are using? Comments here would be unbiased - no manufsacturer's hype - just honest opinions, and the performance that can be expected from such and such scope. It might also help with the recurring question "best scope for a beginner?"

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RE: nexstar 4se good or rubbish

Postby astro_baby » Sat May 02, 2009 1:03 pm

Well as a relatively recent newbie myself (I returned to the hobby after a 20 year absence) I found the buying of a telescope was full of pitfalls.

I at least had the knowledge from a previous period of doing astro about what I would most likely get as a view and wasn't fooled by the 'box art' pictures of Hubble-like imagery. That still left a lot of concerns; could a chinese made refelector really be any good for £170 ? What happened to all the brands I used to know ? Could imaging really be done better/more cheaply than 20 years ago.

The answers to the above were; Yes, they all went bust and no-not really.

One of the big curses I found was aksing other people in astro - few gave truly sensible advice. The classic responses go something like this;

[color=#ffff00]I have £300 to spend on a telescope - what should I buy ?[/color]

Answers tend to be ( and I exaggarete - but only slightly )

[color=#ff9900]"Your wasting your money - wait till you can afford £35,000 for a Plane Wave on a robotic mount"[/color]
This type of answer was the most common - wait till you can afford something superior. The problem is unless you are planning on your own private space mission with a Hubble type telescope there will ALWAYS be something better. I considered a CPC-800 (I had no knowledge of SCTs as they werent around 20 years ago) but as it turns out even the wonderful CPC-800 has its pitfalls.

[color=#ff9900]"Dont buy a telescope - buy some binoculars"[/color]
While this is actually sound advice it completely ignores tha fact that buying decsions are nearly always emotional not rational. If we only ever bought what we needed as opposed to what we wanted Rolex and Farrari would be out of business by next week. Besides while binos will let you learn some stuff they are hard work and the views are never going to equal even a small reflector. Personally I have some wonderful binos but they lack the 'wow' factor of even a small scope.

[color=#ff9900]"You wont have enough cash to image with / do you want to do imaging ?"[/color]
These sorts of answers get the cart before the horse. If you ask a newbie if they want to image they will always say yes - if you ask them if they have endless cash to spend and a dark sky sight and ideally an observatory of course the answer is no. Imaging used to be expensive and complicated - it still is. Yes you can plug a webcam in and get some moon pics but you always could do that with a 35mm film based SLR. If your going to get decent images of the Sombrero Galaxy ( and thats what most newbies think of when they are asked about imaging ) then prepare to be disappointed OR prepare to start spending big time.

This question also assumes the newbie MUST want to so imaging. Belive me the learning curve is steep enough without worrying too much about imaging. Unless you have a lot of spare cash (and time) go with observing to learn the basics. Almost anything you buy at the off wont be up to the demands of imaging.

[color=#ff9900]"Get a refelector, refractor, GoTo, Dob"[/color]

This is where most 'what do I buy ?' threads end up. To the simple all things are simple. In other words newbies just dont have the knowledge (because they are new) to understand all of the issues they think a telescope is a telescope is a telescope. That isn't patronising by the way - thats the way it is.
Its very hard to advise someone on all of the issues in telescopes because its such a big diverse thing. For instance I could advise you of the differences between a Vauxhall Vectr and a Ford Mondeo assuming you know how to drive and are familair with cars. Its would be very hard to tell you the differences bewteen a Jumbo Jet and a Space Shuttle if you were from a tribe in the amazon thats never even seen a ballpoint pen before.

Most 'what do I buy' threads can easily degenerate into something akin to religious warfare. I happen to like reflectors on an EQ mount so will push that because its what I started with and found it to be good but I try to temper my own prejudices and favourites and make sure people are aware of the fact its a personal thing. On another forum someone was advised to get GoTo (A Meade ETX125) they hated it and ended up buying a medium priced refractor. I have also seen people buy Dobs who then cant find anything and get disullusioned. Similarly while EQ mounts are simple enough when you understand them thay can be very frusrating to beginners.

[color=#ff9900]"Go to a Star Party / Astro Club and see what you like"[/color]

This is another good bit of advice but it has its flaws. Open events arent all that common and a lot of astro societies dont do any public astronomy at all - They just go to lectures each month. Theres a bigger pitfall as well. By its very nature an astro society will tend towards people who have already done some of the learning curve. They are very often already on their 2nd, 3rd or 4th telescope.

Dont believe me ? Last night I was at an outreach event ( and very good it was too - thankyou Guildford Astro Soc ) but I tried to see it from a newbie perepctive this morning.

Let me give you a flavour of what scopes were there;

An Obsession 18" Dob - Seriously expensive
A Sky-Watcher 190MN on an EQ6 - exopensive
A Williams Optics Megrez of about 80mm on an EQ6 - very expensive for sure
A Longish Vixen Refractor - didnt get close to it - expensive
A Sky-Watcher large Pro Series SCT - I'd guess about 9-11" on an EQ6 - expensive
A Meade LX90 of about 8-9" - expensive

Seeing the picture emerge - these are all very expensive bits of kit. The only smallish scope I saw there was an unidentified (may have been a Bresser) 4.5" Newtonian. Similar to a SkyHawk 1145.

(my apologies to anyone was there if I have misqouted the exact models and sizes - it was dark and I didn't get to talk to many owners)

So you can see from what was around that a newbie would find it hard to make any sort of judgement based on looking through a collection of high end hardware. Rather like letting someone drive a Bentley Turbo and then asking them if they would prefer a Fiat Punto or a Ford Fiesta.

[color=#ff9900][b]OK Mel - enough already - what would you advise ?[/b][/color]

The best advice I had was this ( and I pass it on gratis) - read some reviews BUT if you find your spending more than an hour a day reading reviews then your doing it wrong. Make a purchase and use that to learn from and accept you will probably not get everything you want BUT you will learn a lot for the next time you buy. In the first purchase get as much aperture as possible, set a budget and stick to it.

I found that was the best advice I had. I bought a Sky-Watcher 130PM which was an excellent scope and fulfilled its mission very well. It was cheap, the optics were awesome and it served me as a learning tool to refine what it was I wanted next time round. To be honest most 2nd hand 130s are sold without the owner having even scratched the surface of its capability.

What made me choose the 130 ? It was universally praised - no one had a bad word to say about it plus Patrick Moore said it was good - I figured if it was good enough for Patrick it was good enough for me.

[color=#ff9900]So what about the Nexstar 4SE ?[/color]

Its a good scope but I personally wouldnt recommend it to a beginner. It has too much potential to put them off.

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RE: nexstar 4se good or rubbish

Postby uea74 » Sun May 03, 2009 9:03 am

A-B, Just found out yesterday that the 4SE was a Mak.Any idea why.
I agree about the advice given, people may give it in good faith but it is often heavily biased one way or another. Sorry but I find that "Get the biggest aperture possible." is one of the main ones. A little odd as very often the next bit of advice is "Buy Turn left at Orion." A book intended for small scopes.[8|][8|]

For a first scope and for a beginner I would hate to recommend anything, my choice was a small goto, but would it suit others? I have no idea. I bought it as it was cheap and although I wanted the big 8SE I really had no idea if I would actually make use of a scope, so bought a small cheaper one. Glad I did as I haven't really used it a lot.So don't feel I spent money then made no use of it.

Seems there are 3 areas: Visual, Imaging and Deep Sky. Each having their own requirments.

To Neil0748 I would say that the 4SE is a middle of the road visual scope. With a 102mm aperture don't push the magnification above 100x.
Have a look through the Messier object list and identify those that are say brighter then Mag 6, then find out where they are and go have a look.
Make yourself a list of double stars and do the same.
Do the same for the significant stars of the sky.
That should take some time and will give a good basic knowledge of what is where.
There is also the moon and whatever planets happen to be wandering around.
There is a lot up there that the 4SE will show.
I am avoiding the imaging side simply because I do no imaging at all and am not qualified on experience to say. Someone somewhere was getting good inaging results from camera phones. Light cheap and may be of some use. Just not sure if it was this forum.
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RE: nexstar 4se good or rubbish

Postby brianb » Sun May 03, 2009 11:16 am

[quote]Just found out yesterday that the 4SE was a Mak.Any idea why. [/quote]
Why not? There are two advantages of a Mak in small size - no complications with collimation as the secondary is permanently fixed to the corrector plate (being simply a reflective film) and a longer focal length, making the scope more suitable for "wow" views of Moon & Saturn, and which is not such a disadvantage for star clusters etc in small sizes. The main practical disadvantage is longer cooldown - again in small sizes this is not really an issue. As for low power work on DSOs, a 4" doesn't really cut it anyway, binoculars would be better.
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