Barlow or bigger lens?

[Jezza94]

hi all, stuck in a bit of a rut here, not sure what to buy...

Do I buy a 2x Barlow lens or a 6mm lens for getting a better look at Jupiter, Saturn, The moon and a few closer Nebulae?

Jeremy

[bojan]

You want to get higher magnification from the same objective/telescope?
If so, buy shorter eyepiece rather than barlow.. Barlows tend to introduce their own aberrations (except very expensive ones, like TeleVue)

[barx1963]

Usually I recommend getting a shorter ep. That has yielded better results for me than a barlow. Remember on many objects more power also magnifies any aberrations, poor seeing etc. In my 12" a 6mm EP was nearly unuseable except on rare nights and a 10mm giving 150x was marginal.
What equipment do you have already?

Malcolm

[Jezza94]

Only using a 70mm Celestron Refractor at the mo'.

I can get quite a crisp picture of Saturn with light pollution coming from a street light right next to my fence with the 10mm. So it will look pretty awesome out of town.

I was thinking of going down to a 7 or 8mm to get a better look at the planets, clusters and larger nebulae.

what do you guys think?

[ZeroID]

With a 7mm you would be pushing the refractors capabilities in all but the best seeing conditions. And surprisingly clusters and nebula do better with larger EPs, not smaller. Again though your 70mm will struggle to get enough light from any other than the brightest. Try M42, the Great Neb in Orion. Middle group of Orions Sword. That is almost naked eye visible in good skies as a faint smudge and in 50mm Binocs is quite viewable.

[LewisM]

For deep sky, you want WIDER - I will use 20mm or 40mm.

Seriously consider perhaps a Vixen zoom eyepiece. Gives you a GOOD range in the one EP.

[Poita]

Send me your address and I'll loan you an 8-24mm zoom eyepiece. Then you can see how various eyepiece sizes work in your telescope.

For planetary you will want a 'smaller number' eyepiece, like an 8mm, for wider views you will want something like a 20mm or 25mm etc.

What eyepieces (lenses) do you already own?

Cheers

-Peter

[Scorpius51]

Some good advice here, Jeremy.

I'd go for the smaller focal length EP, too. But, as already mentioned, there will be a limit to how useful it will be, particularly with a 6mm, or smaller focal length. You generally won't have the conditions to do it justice.

Additionally, unless you get a reasonably expensive 6mm (e.g., Televue Nagler or Ethos, perhaps), you will have a very short eye relief and a narrow exit pupil. So, viewing through a cheap 6mm will not be much fun.

Cheers
John

[Jezza94]

Hi Guys,

Thankyou for all of your help. I only own the 2 EP's that come with the scope, a 10mm and a 20mm.
I will have a shop around.

Jeremy.

[2stroke]

Put them in the bin asap and get your self a nice eyepiece which is in budget of your funds. Some good advise is go for the best you can get if you believe you will keep at astronomy, the reason is you just keep upgrading and wasting money. It's best to go to a local club and try out others eyepeice's though before spending, that way you can get what you want and suites your needs and budget best of all.