suggested eyepiece combo for lunar / planetary work?

[ian_d]

Hi

I currently have a set of eyepieces with my Celestron C6-S (the Revelation set, if you know of it) but I find that they're not necessarily up to scratch for doing high power stuff - lunar and planetary work etc.

So - what would folks on here recommend in terms of the "ideal" eyepiece combo for these purposes? Thinking along the lines of 2 or three good eyepieces, plus a quality Barlow.....anyone got thoughts on good buys to be had out there?

(Incidentally...am toying with the idea of investing in a 100ED apo refractor, so eyepieces that would complement that well are of interest too!!)

All suggestions very gratefully received! :cheers:

cheers

Ian

[GazOC]

For purely planetary/ lunar work and assuming you don't wear glasses when observing I'd say orthos are the best value eyepieces out there.

[lunator]

Gaz

Beat me too it

If you are happy with shortish eye relief orthos are best.

If you use orthos, I wouldn't mix them with barlows.

You can pick up orthos for around £20 S/H so you can afford to get several focal lengths.

Cheers

Ian

[ianmwatson]

Agree with the orthos, and possibly televue plossls, the eye relief is tightish though. IIRC it's a scaled design and the eye relief is 70% of the focal length. I'd probably go with a good quality barlow too.

[ianmwatson]

Ian, why would you not barlow orthos? If you did you'd get more eye relief and I can't see an ortho vignetting somehow.

[dark knight]

Baader seem to do a good range, and some manufacturers produce a range of parfocal eyepieces such as the Celestron XL range which cost about £68 each.

[GazOC]

I never use a Barlow with my orthos. One of the strengths of the design is the contrast they give from having fewer glass elements than other modern designs, putting a Barlow in the chain adds a fair bit of glass and just seems (to me) to go against the point of buying an ortho in the first place. Also orthos are cheap enough that I can afford say all the focal lengths I need rather than having to "double up" eyepieces with a Barlow.

[ianmwatson]

Agreed, with poor quality barlows. If you use one of the good quality ones, televue 2x or 3x springs to mind I don't believe you will see a perceptable difference, well I don't anyway. I have used a 2x with an ethos to split polaris through my 80mm refractor, perhaps not a huge challenge but when you consider how many chunks of glass there are it goes to show how well coated the barlow must be.

The ortho doesn't need many chunks of glass because it only yields on average 40 degrees so doesn't have to correct such a wide field. It's fair to say however that its performance in scopes faster than F6 isn't superb, enter the barlow.

When all is said and done I asked why a person might not bother with a barlow, and Gaz I take your point. And maybe the question is why bother doing it? So, I suppose there's 2 reasons, to yield longer eye relief or increase the effective F ratio of a fast scope.

[ian_d]

Cheers guys, that's a very useful discussion! Might look into the Baader ortho range. Also - another quick question - what's the big attraction of the Televue Nagler / Ethos eyepieces? Seem super-expensive...so what do you get for all that cash? :-)

Ian

[GazOC]

I have a Televue x2 and I can tell the difference in views when using it with orthos (whether its all in my mind or whether I could do a 'blind test' and tell the difference is another matter!!). As you say its personal opinion, but the tight eye relief has never bothered me and the performance of orthos in faster scopes in a bit of a non issue IMHO, if I'm using my orthos then I'm usually looking at the moon, planets or double stars and not likely to be using a f6 or f5 scope in any case.

But to each his own..

[GazOC]

Cheers guys, that's a very useful discussion! Might look into the Baader ortho range. Also - another quick question - what's the big attraction of the Televue Nagler / Ethos eyepieces? Seem super-expensive...so what do you get for all that cash? :-)

Ian

Basically you are paying for a large, well corrected field of view which give great views of larger or extended objects but arn't really needed when viewing planets with a driven mount as the object should be centred in you field of view.

[TheThing]

Never had any problems using my ortho with a Barlow and neither do I find that the eye relief is too short either.

'Suck 'em and see' as one of my old bosses used to say!

[GazOC]

I've never had any "problems" doing it either, I just prefer not to.

[TheThing]

Ok, check!

Thanks for clarifying Gaz.

[Doc]

I have five circle T orthos and they perform so much better in my Tal 4" refractor at F10 then in my 16" Dob at F4.5.

They are a cracking eyepiece for Moon, Planets and star splitting.

[John]

....

Also - another quick question - what's the big attraction of the Televue Nagler / Ethos eyepieces? Seem super-expensive...so what do you get for all that cash? .....

On Naglers, what you get is an ultra wide field of view which is sharp right across, even in short focal length scopes. The coatings, glass quality and engineering are superb leading to performance that is, IMHO, up there with the very best - even with specialised planetary eyepieces. I've tried my Nagler T6's against some good quality Orthos, TMB Planetaries, Tele Vue Plossls, Vixen Plossls and the Naglers at least matched the quality of the views of the best of them and added the 82 degree fields of view and 12mm of eye relief

As my scopes are shortish focal length and on undriven, alt-azimuth mounts the wide, sharp FoV makes for more comfortable viewing.

In longer focal length scopes and / or if you are comfortable with a smaller field of view I would agree that the additional investment is not going to give such a big dividend. You pays you money and makes you choice I guess - or perhaps that should be makes your choice then pays your money !.

As for the Ethos - I'll let you know if we get some clear nights later this week

John