I purchased a 5SE and have been playing with it a few days. I saw the Andromeda Galaxy for the first time yesterday in my 25mm eyepiece that came with the scope (f/10). Definitely could see it but it appeared as a dim smudge. If I had the 6SE would it be much brighter? OR if I went out in the country where it is darker, would that have more of an effect? or both?
NexStar 5SE vs 6SE (or 8SE) question
Posted 10 September 2019 - 10:24 AM
The 6SE may be the best balance of power, stability and portability. But getting out of town will show you more with any telescope. There is a really good telescope review site called scopereviews.com. I was just reading Ed's review of the Nexstar 8i which Ed describes as wobbly and top heavy. Galaxies will be dim in any small scope, but a C5 was my first scope and I had a lot of fun with it.
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Posted 10 September 2019 - 10:37 AM
And this time of the month the Moon is pretty bright. That probably played a part too.
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Posted 10 September 2019 - 11:16 AM
A .63 focal reducer would be even better on your C5 since it would increase the field of view of your 26mm eyepiece, provided it was a 1.25" eyepiece.
The larger scopes, C6, C8 would generally be nicer more potent Deep space telescopes but in the case of Andromeda, you are looking for a wide field of view to see the entire object or as much of it as you can see, so for what you have, the C5 under dark skies would be a very nice scope for this.
Under dark skies, you will also notice M110 and M32 along with M31, so the darker skies will give you more pleasing views.
You have to be realistic however, and not expect to see the entire disk like you see in astrophotography and definitely not with the details Astro photos show.
I have both a C6 and Edge 8, and while everyone seems to think the Edge scopes are something special, I prefer the views through my C6 usually more for back yard observing, since its more portable and takes a lighter mount and has wider fields of view. If I was going to a dark site however, the larger aperture seems to always win out.
Edited by aa6ww, 10 September 2019 - 02:09 PM.
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Posted 10 September 2019 - 11:17 AM
1250mm focal length, 25mm eyepiece, mag = 50x, field of view therefore around 1 degree.
You were seeing about 1/3 of the Andromeda galaxy and just the central core. That is a big and somewhat uninteresting ball of stars.
To see M31 try binoculars and somewhere dark. Dark as in sounds you can just hear scare you.
If you have to pont a scope then oddly the Meade ETX 80 is pretty good for M31, The Skywatcher ED80 with a 24mm 68 degree eyepiece will be about as good as it gets. Again somewhere dark.
Really M31 is or can be a bad/poor object to look at in the majority of scopes. It just doesn't come across in most instances.
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Posted 10 September 2019 - 11:52 AM
Actually the best view I've ever had of M31 with with a pair of 11x80 binoculars on a moonless night at Bryce Canyon National Park. The 11x80s had a 4.4 degree FOV and M31 spanned about 1/2 the field.
Supposedly you can see over 7k stars on a moonless night with good transparency there.
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Posted 11 September 2019 - 04:02 AM
I purchased a 5SE and have been playing with it a few days. I saw the Andromeda Galaxy for the first time yesterday in my 25mm eyepiece that came with the scope (f/10). Definitely could see it but it appeared as a dim smudge. If I had the 6SE would it be much brighter?
You can do the arithmetic as well as I can. A telescope's light-gathering capability is proportional to the square of the aperture, so a 6-inch scope gathers 36/25 = 1.44 times as much light as a 5-incher.
A 44% increase is not entirely trivial, but it doesn't make a major qualitative improvement to your view of any object. Yes, the difference would be obvious if you set up both scopes side by side. But if you gave me a scope draped in cloth so that I couldn't tell if it were a 5-incher or 6-incher by looking at the scope, and pointed it at M31 and asked me to guess the aperture, I would have only a 50-50 chance of guessing whether it was a 5-incher or 6-incher. That's because when viewing a galaxy, aperture matters much less than dark skies.
OR if I went out in the country where it is darker, would that have more of an effect?
Yes, much more of an effect. The sky in a typical suburb glows at least 10 times brighter than the sky at a pristine sky. Which do you think would make more difference -- a 1.44x increase in aperture or a 10x decrease in light pollution? Based on numbers alone, the latter, right?
And the difference at the eyepiece is even bigger. Frankly, I get a better view of M31 from a dark site with no optical aid at all than I do from a typical suburb through my 7-inch scope. And if I'm allowed 7x35 binoculars at the dark site, the comparison becomes so one-sided that it's not even worth discussing.
The problem is that the outer parts of any galaxy are much fainter than typical suburban skyglow, which makes them effectively invisible.
Edited by Tony Flanders, 11 September 2019 - 04:02 AM.