Celestron NexStar 4SE

[kjs1977]

Hi,

I have the above scope which I bought at Christmas as it was on offer.  I have the following eyepieces

• Orbinar PL 4MM
• Orbinar PL 6.5mm
• Celestron 9mm PLOSSL
• Celestron 25MM PLOSSL
• SEBEN Barlow X2

What should I be able to see? So far I've been able to spot, obviously the Moon, Jupiter and moons (although not very clear), Mars.  Should I be able to see Nebulae as seen in some pictures?  Having searched prior to posting I saw one forum user who took an awesome image of a Nebulae with the 4SE and a DSLR.

What should I invest in? Budget is tight at the moment so won't be able to fork out for much.

Any help would be very welcome.

Regards,

Kian

[baggywrinkle]

The 4SE has a focal length of 1325mm so be careful with the use of the 4mm and 6.5 mm ep's and do not use them with the barlow as they would be too powerfull. The 4mm is over the top already, but hang onto it in case at a later date you get a different scope.

As a rule of thumb the max mag would be around 2x the objective so 200x

the 4mm = 330x

6.5mm = 203

9mm = 147

25mm = 53

Start with the lowest power and work up if the seeing is good. Max mag do0es not = best views

Low mags are often best for DSO but your scope has a  long focal lenght and more lended to planetary.

And welcome to SGL

Edited March 7, 2014 by baggywrinkle

[LukeSkywatcher]

I agree. The 4SE scope and the 4mm or 6.5mm eyepiece is simply pushing the scope/magnification way above what is usable in this part of the world. The 9mm will be fine on its own. The 25mm will be pretty good for widefield views.

I'd really only use the barlow with the 25mm which will give you an eyepiece of 12.5mm.

9mm,12.5mm and 25mm is a pretty good range to have.   

[Qualia]

What should I be able to see?....Should I be able to see Nebulae as seen in some pictures?  Having searched prior to posting I saw one forum user who took an awesome image of a Nebulae with the 4SE and a DSLR.

Sound advice above and not a lot I can add, but I feel we've also got to start putting stuff into perspective, Kian.

First of all, do not expect to see celestial objects as they are displayed in astro-photography. These images are acquired with very, very long exposures utilizing sensitive CCD cameras.

With anything except bright stars, the planets, and perhaps a very subtle hint greenish or bluish hue in some nebulae, one should not expect to see colour, nor the detail offered in astro photography. The colour receptors in the eye are simply not sensitive enough to perceive colour or detail over distances of tens, hundreds, thousands and millions of light years.

To get an idea, check out these 10" sketches of two nubulae observed at a super dark site and compare them to a couple of snazzy astro-photos:

One should realize by now that the pretty colour pictures on the boxes of department store telescopes are not what to expect in the telescope’s eyepiece. Visual observers simply cannot expect Hubble-like vistas, instead they try to learn good observational skills, and enjoy the spectacular wonder of the cosmic night sky that their gear can offer.

The eye is relatively small when we compare it to the vastness out-there and although the amount of light it gathers serves us well for our daily life on this floating rock in space, it's not so great at viewing anything billions and billions and billions of miles away . Instead, we augment our eyes with the use of our telescopes. The larger the aperture, the more photons of light are gathered and sent to our eyes.

In a very real sense, the visible universe is some 14,000 million light years in size in all directions , and in your own case you've got a little bit of 4" glass looking out upon it   I have the same and it blows my mind we are able to see anything . But we've got to be realistic about what we are going to be able to see.

Now in practical terms, you've got yourself some mighty high power eyepieces which in all honesty might not be used that often. I mean, in my own 4" I'm not pushing 200x and most often top power in the frac is about 170x. When viewing, you'll probably find 50x to 80x most useful for DSOs and between 125x to 180x for planetary and lunar work.

Before I make this post into a tiresome bore , I'll just add one more idea to dwell upon. Regardless of the scope being used, observational skills are really important. If you want to take this hobby, nay, this way of life seriously, you must develop good observational skills to fully appreciate the benefits not only of your scope but also of the wonders of nature. 

Learning skills such as sitting attentively and patiently, asking yourself questions at the eyepiece, using averted vision, are all very important skills to develop.

If at the beginning of your progress in astronomy, I ask you to look upon a faint fuzzy, no doubt you'll say you don't see much, if anything. But I'd bet you my bottom dollar, if I asked you the same question at the end of the year, you'd be lost for words to explain the complexity and detail your eye has captured. That seems to be the way this game works. It seems to me that visual astronomy is a noble art with a whole bunch of skills needing to be learned if we wish to appreciate the wonders available.

Edited March 8, 2014 by Qualia

[baggywrinkle]

Invest in a copy of 'Turn Left at Orion'

It has stacks of drawings which show what a visual observer to expect. Qualia's advice above is spot on!

[jonathan]

Have a look at The Sky At Night website, it has some very well written guides and night sky tours.

http://www.bbc.co.uk/programmes/b006mk7h

Pete Lawrence's Moon Guides should be of particular interest as you have an excellent scope for lunar observing.

[kjs1977]

Thank you so much for the sound advice. TBH I wasn't expecting to see anything like what's been printed in Astronomy Photographer of the Year:) and I will be happy enough to see an odd blur here or there.
 
 

As a rule of thumb the max mag would be around 2x the objective so 200x
 
the 4mm = 330x
6.5mm = 203
9mm = 147
25mm = 53

I think I'm still having difficulty in getting my head around the numbers above?  The smaller the number, the more powerful the EP is? Therefore the 4mm would give me a magnitude of around 330 x the actual object being viewed?
 
What should I use to view, Jupiter for instance to give a good quality image? I'm not sure which EP I used but when viewing I can just see, if I squint enough to see the stripes on the Giant.  Should I be able to have a good clear view and see the GRS?
 
 
It's true, I do need to educate myself better of the night sky. Sure I can look up and point people to Sirius, Jupiter, Mars, Orion but should be able to do a lot more.  I have subscribed to the Sky At Night magazine, got an offer at Christmas, 1st 6 issues for £5. Can't go wrong there Didn't realise there were more details on the SAN website?
 
Best get cracking.  Again, many thanks for the education!
 
Kian

 
          Qualia Many thanks for going into great detail. As mentioned above I wasn't expecting glorious images, but often wondered if I should at least be able to see that there is something there?

[baggywrinkle]

Yes the lower the ep number the more powerfull.

Divide the focal lenght of the OTA by the ep focal length to get the magnification.

But as I said a rule of thumb for max power is roughly 2x the objective diameter of the OTA. The SE4 is roughly 100mm so 2x100=200 the max working power.

BUT it also depends on seeing. If the atmosphere is warm and there are lots of thermals then the image will wobble, increase the power and you get more wobbles and often blurring.

The 9mm should give decent views of Jupiter.

But in general terms work from low power upwards, you can then judge the deterioration, if any, as you increase the power.

Using the barlow helps, but it can mean a less brighter image (and less contrast)  as there is effectively more glass between the object being viewed and your eye.

[mikehab]

I have the 4SE and have found it very difficult indeed to capture DSOs/Nebulas.... the only one I've managed to capture so far is M42 (see below).   As it's relatively 'slow' at F/13 you certainly won't be able to see anything visually except for really bright objects like M42 and maybe some of the clusters (M11 / M13).   As is usually the case though - it all really depends on how dark your skies are and how much light pollution there is ... I'm in NW London so really struggle.   Also the tracking on the 4SE mount isn't that great ... so not good for long exposures, even when EQ aligned with the wedge.

Cheers,

Mike

[Nexstar4se]

I have a nexstar 4se, and i find it to be a nice planetary nebula hunter, its really good at it, ive done the eskimo nebula in high detail, blue snowball, saturn, orion nebula, hubble var., M78, flame nebula, andromeda, and one thing to do, is to get the F6.3 reducer, which will put the scope at ~F/8-10 (havent really tested)

 

[joe aguiar]

Biggest factor is where you live and how much light pollution u have. 2nd remember you have a 4 inch scope which is made for high power views. 

4 inch is not a big scope for dso it's ok size for the planets.

The standard is if you are serious about seeing dso the 8 inch size is the minimum. 

That doesnt mean there isn't some of that bright stuff u cant see either. 

I agree as well those 2 ep are too much mag u really need something lower and the 25mm ep since your scope is soo long, a 32mm ep

Joejaguar 

Edited December 6, 2019 by joe aguiar

[joe aguiar]

Sorry the other part to your question about what will u see is get a planisphere and a good book like night watch.

There like 20 pages of star maps inside of maybe the best and brightest 150 for u to start with.

Joejaguar