Eyepiece Help Please for my SkyWatcher 250PX

[Rorth72]

I have recently bought a SkyWatcher 250PX Dobsonian. I am very pleased with it and have had some great nights viewing so far. I am new to astronomy, so I am on a steep learning curve.

The telescope has a 254mm Mirror and a focal length of 1200mm (f/5). It came with two eyepieces, a 25mm and 10mm, giving magnifications of 48x and 120x. I am using this scope as an all round scope, so will want to use it for DSO as well as Planetary and Lunar work. I have read that the 10mm EP that is supplied isn't up to much and I am not sure how the 25mm compares to better EP's. As I want to do a wide range of observing on this scope could anyone please let me know what EP's I should invest in. I will want a range that can cover it all. Also should I ditch the two that I have also? So basically, just want a range of EP's that will cover from wide field DSO down to high magnification for planetary work.

Also do I need to get any filters? (not sure what they are used for).

Thanks in advance!

[pbyrne]

What's your budget?

A decent set of eyepieces will be something like:

30-35mm for lower power work. Magnification x34-x40

13-20mm for medium power. Magnification x60-x92

5-10mm for high power work. Magnification x120-x240.

The addition of a barlow will double the collection to six eyepieces.

As to what brand, that's an open question, and down to your budget, there are many excellent eyepieces out there such as the Meade Series 4000s and 5000s, Celestron's Ultimas, the Baader Hyperions, if you have more cash then there are the Televues and the Pentaxes.

If you are a member of a club, then I am sure that fellow members will let you see how their eyepieces perform in your scope.

There are different types of filters, coloured filters bring out details on the planets, a different colour for a different detail. Nebular filters bloke out certain wavelengths of light to allow fainter objects, planetaries, emission nebula, etc., to be seen. One of the better ones is the UHC which I think is a good all round nebular filter.

[NGC 1502]

Some good advice in post #2. It's tough to give definite advice as to makes,

as much depends on your budget.

For my 10" Dob, I use 3 eyepieces most of the time, a 27mm, 14mm and 8mm,

to give 44x, 85x & 150x. On good nights I use a 6mm, 200x, for planets and

double stars. The 14mm gets most use.

One thing to remember, with your F5 scope, you have to pay a lot for a sharp

view towards the edges, or pay less and accept fuzzy stars away from the centre

of the field of view. Only you can decide if you want to go for premium eyepieces,

but lots of folk are very happy with less than premium glass.

Personaly, I would get a set of eyepieces before filters. Eyepieces are needed for

all your viewing, fiters are only useful for specific targets.

Best regards, Ed.

[tomw28]

How long have you had your scope? Give it a good couple of months before upgrading the EP's, just so you can find out exactly what you want the EP's for (planets, clusters, nebulae). Don't just jump in, the £80-£100 you spend now could be added to the money you'd have in a few months to get a really nice EP that does what you want, rather than a handful of average quality EP's that don't what you want.

As for filters, get a cheap lunar filter. They can be got for less than £20, and without it you'll be walking around bumping into stuff after looking at our nearest neighbour! For other more expensive filters, again wait until you know exactly what it is you want to see in more detail.

[david o]

To be honest I'd be tempted not to buy anything for now and just use what came with the 'scope. With eyepiece time under your belt you'll know what needs replacing, or if there's a gap that needs filling.

For the basics of choosing EPs, you might find these posts helpful : [thread=80772]"Eyepieces - the very least you need"[/thread] and [thread=63184]"Understanding and choosing eyepieces"[/thread].

As for filters, a lunar filter is probably the only real "must have".

HTH

[david o]

Just had another thought :

At f/5 your 'scopes optics will be quite demanding on the EPs, so it'll be worthwhile spending on reasonable quality glass.

Buy with an eye to the future too - build up a set of decent quality EPs that'll stay with you as your observing preferences change, along with your 'scopes.

HTH