First Scope Advice: Celestron 102 SLT vs 4or5SE

[Sharpe]

Hi everyone,

I am looking at one of the following as an introductory scope:

Celestron 102 SLT http://www.firstlightoptics.com/slt-series/celestron-nexstar-102-slt.html

Celestron Nexstar 4(or)5 SE http://www.firstlightoptics.com/se-series/celestron-nexstar-4se.html

http://www.firstlightoptics.com/se-series/celestron-nexstar-5se.html

I am hoping these will meet my main aims of observing mostly DSO’s and some orbital bodies (probably a 70/30 split in favour of DSO’s) and a little light AP (as far as the alt/az mount will allow).

As I will be travelling a lot and don’t have much storage at the moment these tick the ‘grab and go’ box very nicely. I want to avoid reflectors due to their fragility and collimation issues (these will be getting moved a lot and thus need to be rugged) and I would like to avoid a dob due to size and space issues. As a noobie, GOTO is a must.

I thought one of the 3 scopes above would be an ideal place to start as they can be mounted on NEQ5/6’s which I intend to buy at a later date I may even buy a bigger/better/different telescope to go with NEQ5/6 in the future when I have more experience, space and money. This route therefore allows me to get a fast scope for DSO’s and a slower scope for the rest while also giving me time to get a decent AP mount all in due course as experience, time, money and life allow.

Budget isn’t really an issue here, I was originally going to buy a 9.25” SCT on a CG-5 (£1400) but decided to ‘build up to it’ rather than jumping straight in as I understand that the 9.25” really isn’t going to get the job done DSO wise, even with a focal reducer and the CG-5 mount would have been a little under mounted on a CG-5.

I have 5 questions:

1. Does anyone have any practical experience of any of the above – what do you think of them? Have you used a combination of the above scopes – how did they compare?
   
2. The 102 SLT has a good focal length for DSO AP (F6) – as the SE4/5 have F10 or above does this mean they won’t be able to handle DSO’s and DSO AP?
   
3. I am thinking that if I get the 102 SLT I can use that as my DSO AP OTA in the future and perhaps buy an 8 or 9.25” SCT in the future. Would the 102SLT suit this task and/or would the SE4/5 be able to keep up?
   
4. Is the built in wedge on the SE4/5 going to be of much use AP wise or does the focal length rule it out entirely for DSO’s and AP work?
   
5. Totally aside from the OTA’s – can anyone recommend a good power supply for the above telescopes that is also compatible with the NEQ5/6 that can handle 2-4 heater strips?
   

Many thanks in advance! Looking forward to your advice and opinions

[GeorgeB]

I'm a happy 102 SLT owner and I can heartily recommend it as a good all round GOTO scope. It's very good for DSO's as it gives nice wide fields of view. However, for the moon and planets it does suffer from colour fringing effects, which is typical for this type of achromatic refractor. The 4SE/5SE will give you a sharper cleaner view of the moon and planets, but it is not as good for DSO's compared to the 102SLT due to the longer focal ratio. The 102 SLT also has more light gathering than the 5SE as the 5SE has a central obstruction to the mirror where the 102mm refractor doesn't. I would say that the 102SLT would be better value than a 4SE.

I ended up buying a Mak 127 to complement my 102 SLT for moon and planetry viewing as this uses a similar type of optics to the 4SE.

The power supply I use is a cheap and cheerful 3-in-1 power pack from Maplin.

[GeorgeB]

Just to correct the above - I mistakenly compared the aperture of the 5SE to the 102 SLT, I should have said the 4SE. The 5SE will have more light gathering capability than the 102 SLT, even with the central obstruction.

[rowan46]

The 5se is the best of the 3 scopes but if budget isn't a problem I would get the 6se it's got a slightly better mount is just as portable and gives slightly better value on the pounds per inches apparture front. I know the 6se doesn't have a wedge but to be frank the wedge isn't much better than a decoration it doesn't work that well on either the 4 or 5se. I have the 5 and it's a great scope. especially under dark skies but the 6 is better value and performance.

[Sharpe]

Thanks for the opinions and advice so far

- Any more out there?

[rowan46]

As you are thinking of getting 2 setups eventually why not do it right get yourself a good visual system then a good photo system so for visual get a 200p dob then later get the heq5 or neq6 and an 80mm fast apo at a later date.

[Ags]

I have a 4SE and an ST80 (similar to the refractor you are considering).

None of the scopes you are looking at are good for DSOs as these benefit from aperture first amd foremost.

That said, my 4SE gives good views of the brighter, smaller DSOs and the views are more pleasing (sharper, cleaner) than through the refractor, which shows false color around all the bright stars and gets fuzzy toward the edges.

I have never used one, but of the three scopes you have looked at, the 5SE seems the best as it has most aperture, and it has a slightly shorter focal length than the 4SE so it shows a slightly wider view of the sky with the same eyepieces.

The 4SE is good at planets (I imagine the 5SE is too) but based on my experience of the ST80 I would say that the refractor would be merely OK for low-power sweeping of the sky.

[JamesM]

Go for the largest aperture if DSO observing is what you are interested in. As far as astrophotography is concerned, an alt-azimuth mount of the type mentioned above will limit you to just solar system objects via a webcam, stacking the best 'frames' on top of each other using Registax to construct a final composite image. To image DSO's effectively you will certainly need a HEQ5 as a minimum (good auto guiding capabilities which improves polar alignment) along with a fast refractor. Imaging specifications are quite different from those for observing and any investment in this area must always start with the mount. I would certainly recommend getting hold of a copy of Steve Richards' "Making Every Photon Count"( FLO £19.95) which will provide you with a comprehensive understanding of what kit you need and why you need it to take good consistent images. As they say, "the stars aren't going anywhere" and if imaging is your long term goal then I would read this book before buying any kit to see if it may influence your choice of what to get now in the interim period.

Clear skies

James

[CFC]

I have the 4SE and it's really easy to transport and gives nice views. With a small aperture you're limited in terms of DSOs. Aperture fever being what it is, get the 5SE if your budget allows

But unless you're made of money you might really want to consider actually NOT 'building up to it' but just going for what you want in the end. (unless you're going to keep all scopes you acquire) I spent £400 on my 4SE as a first telescope for husband, and now I wish I'd gone straight in for the 8. For the seemingly rare nights you can actually get to view anything in this country, you might as well get the best views you can.

[LukeSkywatcher]

I have the 4SE and it's really easy to transport and gives nice views. With a small aperture you're limited in terms of DSOs. Aperture fever being what it is, get the 5SE if your budget allows

But unless you're made of money you might really want to consider actually NOT 'building up to it' but just going for what you want in the end. (unless you're going to keep all scopes you acquire) I spent £400 on my 4SE as a first telescope for husband, and now I wish I'd gone straight in for the 8. For the seemingly rare nights you can actually get to view anything in this country, you might as well get the best views you can.

I'm not made of money but over the last 5 yrs i have slowly built up to my ultimate scope (Celestron 8SE). This is ok though because the total cost of my other 3 scopes combined is about 600 euro.

On the 8SE, i pushed the boat out and went for the one that i will probably use for the rest of my observing life.

The only scope i own that i would consider selling is my first one.................Celestron 90mm refractor on an EQ mount. I love the scope but hate the EQ, so it just gathers dust.