What eyepiece?

Horatio · #1 30-07-2007, 09:11 PM

I'd like to view a messier object with decent resolution. Obviously, I'm new to this hobby.

I have a 10" LX200, barlow and at the moment just a 26mm eyepiece which came std.

What magnification eyepiece will I need (at least)? If you can assist it would be appreciated.

Remember, I am new to this so please, be kind...

erick (Eric) · #2 30-07-2007, 09:37 PM

Perhaps a little more information? Which Messier object or do you mean any one of the 110? Also, what magnification is your barlow - 2x or more?

There are others better qualified to answer, but I think they'd want this information at least.

Edit: Oh, and I bet they'll ask how much you could to spend on the eyepiece(s?)

Horatio · #3 30-07-2007, 10:01 PM

Thanks for pointing that out erick

Its a 2x barlow. I'll just take a step at a time, but I would like to see a lot more detail than what I am seeing at the moment. I've been told that beginners often go power crazy at first.

As for the $... I'll cross that bridge when I come to it.

erick (Eric) · #4 30-07-2007, 10:22 PM

.."power crazy". Yes, in no time I was shoving a 6mm eyepiece into a 2x barlow and looking at Venus as it sank to the west -

I mentioned "which of the Messier objects" because they are a diverse set ( http://www.deepskyobserving.com/ ) and the magnification you would want varies very widely.

Don't know why the experts haven't jumped in yet, so I'll rabbit on. I think your LX200 has a focal length of 2500mm? Therefore your 26mm eyepiece is giving you about 96x. I think there are objects (say M42) where you want to be down more around 40-50x. But there are others where you would like to be up around 400x, maybe?

Anyway, I think we have the message - you want some higher magnification options.

Horatio · #5 30-07-2007, 10:40 PM

erick, to me you sound very knowledgeable. Thanks for replying. I'll just go on the hunt for an eyepiece/s.

I'll continue to operate by trial an error at the moment. I have no complaints with this method as I'm enjoying every minute of it... despite the fact I haven't got a clue!

Cheers

iceman (Mike) · #6 31-07-2007, 06:22 AM

Hi Horatio.

Your 26mm will give you very good views of many of the Messier objects in your 10" LX200. As Eric pointed out, at a magnification of 96x is about perfect for most deep-space object viewing.

When combined with your 2x barlow, it will give you a magnification of approx 190x, which is perfect for higher-magnification deep-space viewing such as planetary nebulas, close double stars, and of course the planets and the moon.

So, you don't need to rush

Wheer abouts do you live? Are there any astronomy societies near you?

rmcpb (Rob) · #7 31-07-2007, 08:29 AM

Horatio,

Mike hit the nail on the head. Your two magnifications are two of the most commonly used ones in general astromony.

Now I will give you my standard advice, use your scope a lot, learn to set it up and align it, get a feel for what you want to look at (Erik was right the Messier objects are a strange group of objects), learn to navigate your way around the sky and most of all see if you can make contact with a local astro society.

After a while you will get to know what you really want to view and will make informed descisions and not end up with a draw full of expensive paperweights.

Before new eyepieces a red torch, planisphere and a set of 10x50 binoculars would be a good set up IMHO.

Keep looking up and asking questions.

Cheers

casstony · #8 31-07-2007, 10:12 AM

Definitely best to get out observing with others if you can, but if you can't:

From www.andrewscom.com.au
guan sheng 2" SCT dielectric diagonal $79
guan sheng 2" achromatic barlow $49
Andrews 30mm 80 degree ultrawide eyepiece $99

This eyepiece will provide a much wider field of view than your 26mm(which I assume is a 26mm plossl). You can put the eyepiece in the barlow to double the magnification or you can unscrew the barlow lens from its tube, screw it directly to the eyepiece and have 1.5x magnification.

If you load extra weight on the rear of the scope you might also need a balance rail such as the Bintel 2D counterweight system ($129) to avoid straining the drives. www.bintel.com.au

The setup I've suggested is one of a myriad of possibilities.

Taking your scope away from steetlights to a dark site will improve deep sky views far more than any equipment you could buy.

Welcome to IIS.

janoskiss (Steve H) · #9 31-07-2007, 11:25 AM

near 2mm exit pupil will give you the best view of most messier objects. For your f/10 system a 20mm ultrawide would be ideal. On a conservative budget, I'd give this EP a go: https://www.bintelshop.com.au/Product.aspx?ID=7508
And this one when you need more TFOV for few of the larger objects:
https://www.bintelshop.com.au/Product.aspx?ID=7509
In an f/10 scope these EPs will perform well. (the 30mm I've used, the 20mm I have not)

Horatio · #10 31-07-2007, 11:30 AM

Thanks to everyone for thier advice.

The bits and pieces are endless - my pocket is not (unfortunately)

I think I'll just cruise along and see how I go. "No rush" as Iceman said.

I live approximately 30km out of Goulburn NSW. I'm fairly sure that there is not a club anywhere close. However, I will be moving to Wagga at the end of the year so the ASAW will not be too far away and I think that Wagga has it's own club as well.

Cheers

KG8 · #11 31-07-2007, 01:15 PM

Here is another opinion for you to consider...

with a 10" SCT you have a pretty narrow field of view, so considering your current ep/barlow I would be looking for less magnification myself. Putting a 40mm ep in that scope will allow better views of larger things like omega centauri. Asterisms like the jewel box will be sharper and more colourful also. You will find that on nights when the "seeing" is average or poor (in other words a lot of the time) a lower magnification will show objects with much more clarity than with your higher magnifications. It's a matter of choice really, a trade off between clarity and a little more detail. Personally I prefer a clear sharp view over a larger not so sharp view anynight. As an example I regularly view the little eta carina homunculus nebula with a 40mm in my 11" and prefer the crisp clear view this gives me to one which is larger but less distinct.

rmcpb (Rob) · #12 31-07-2007, 02:05 PM

Horatio,

How keen are you? Goulburn to Campbelltown equals the Macarthur Astro Society. Too far???

Cheers

Terry B · #13 31-07-2007, 03:53 PM

My scope has a focal length of 1800mm, a bit shorter than yours. I only use 2 eyepieces with any frequency. A 24.5mm (conparable to your 26mm) and an 8mm plossl giving 225x mag. The higher magnification is good for smaller planetary nebs, planets, occasional small galaxies and double stars. It would be used 5% of the time only.
The one like you have is the standard workhorse. Something between 10mm and 13mm would be similar on your scope. Your barlow turns your 26mm into a 13mm as it is although probably with a more degraded image than a native 13mm eyepiece. A 10mm would be good for the planets.