Eyepiece with Barlow question

[Skwerl23]

I have an Orion xt8

I want to buy a Barlow and an eye piece.

I was curious if a 10mm or 12mm with a 3x Barlow would be better

Or an 8mm with a 2x Barlow.

Also with one or the other and aroun 100-120 what mix would you get? I want to get a little zoom for planets I have a lot of light pollution so planets are amazing here.

Some helpful thoughts or links would be much appreciated.

[Capricorn]

The XT8 has a focal length of 1200mm.

Generally the maximum recommended is said to be around the 200x mark, that would mean 6mm combination.

A set up to give 4mm gives 300x.

The combinations to give 300x give me the concern that you are aiming for the very highest that I suspect you will manage to use only occasionally and all that glass in the optical path would have to be good so that the image is not too bad. You will be getting hit by having high magnification and possibly not too good glass.

To get 100-120x means 10-12mm.

I would be tempted to reduce the maximum magnification a bit and go for a 10mm and a 2x barlow, giving 240x as a combination and 120x with just the eyepiece.

Much will depend on the budget also what other eyepieces you have.

I will point out that I am not a fan of barlows as unless good thay degrade the image, and in your place I would get the 5mm, 8mm and 12mm Astro-Tech Paradigms.

[alan potts]

I agree with Capricorn, if your going up to 300 then you will need top glass. I would set out my stall to go no higher than 240-260. If you buy an eyepiece that gives you this without barlow you would benifit with less glass in the opical path. However, I have eyepieces that can do this and a powermate and I can never see the difference.

Alan.

[John]

For $100-$120 the best optical option might be a 6mm and a 4mm orthoscopic. There will be compromises in ergonomics and field of view but, if you can handle those, the views would be as good as you can get for your budget.

The University Optics orthoscopics should be well within your budget and come up regularly on US classifieds sites such as Astromart and the Cloudynights forum.