Help with eyepiece selection

[cfrommen]

Hi there!

I have so far mainly used DSLR/webcam with my telescope but now like also to "observe". I don't have any eyepieces yet except for some really cheep Plossl eyepieces 40mm, 25mm and one Vixen Lanthanum 9 mm that I used occasionally when I owned a Nexstar 4 and 11)  and I am looking for some advice what I should get.

Telescope: 130/780 mm APO refractor

Televue 2.5 PowerMate barlow

Location: suburbs/small village with some light pollution from nearby streetlight (sigh)

I wear glasses so need some eyepieces wirh good eye-relief

Will probably start with lunar/planetary observation but also interested in Deep-Sky .

Read good things about the Vixen NLV New Lanthanum eyepieces. They seeem reasonably priced and offer good eye-relief. What focal lengths should I choose to cover the "whole range"? I plan to buy about 4 eyepieces in total. Any alternatives to the Vixen?

Any help is appreciated.

Best,

Christoph

[russ.will]

Hello Christoph and welcome,

I think the NLV are being replaced by the SLVs, but it's an evolutionary rather than revolutionary change - There is still plenty of focal lengths, they still have the 20mm of eye relief you'll need as a glasses wearer and they still go for a high quality, but modest field apparent of view at 50 degrees.

Low Power. I'd go with the 25mm, which will give 30x magnification and a shade over 4mm exit pupil. That's a good wide field EP and at 4mm exit pupil, it will keep the background sky reasonably dark.

Medium Low. 50x give or take, for the larger DSOs implies the 10mm is a good fit.

Medium High. Something around 100x is always good to have so lets say 10mm in the SLVs. 1.3mm exit pupil is ideal.

Highish. I'd probably go 6mm here, even though at 130x it's not that high. It is a 1mm exit pupil and that will work well with smaller DSOs like globulars.

The other reason I've not gone too high on the power, is because you have a 2.5x Powermate. Use that with the 10mm SLV and you're pushing 200x with 4mm and depending on your eye's age and your sensitivity to floaters, that may be at the limits of pleasurable viewing, due to a 0.66mm exit pupil.

That's my take and I'd suggest that even if you don't go Vixen SLV (someone will be along to recommend Televue Delos at least triple the price any minute now!) that type of range of magnifications in concert with the Powermate will give you a good spread to be going on with.

If you want to spend less, than the Vixens, then the BST Starguider EPs (about £50 in the UK) are very good value, although the 16-20mm eye relief quoted is probably about 3mm too generous as the eye-cup design eats up at least this much. Celestron X-Cel LX for a touch more and like the BSTs, the 60 degree apparent filed of view feels quite a lot larger than the SLVs.

If you do want to spend more, then the pinnacle of long eye relief EPs are the aforementioned Delos, but they do cost. On the other hand, it's unlikely as a glasses wearer, you'll ever feel compelled to upgrade them, as there is basically no where to go.

Russell

[Roy Challen]

The NLVs have been superceded by the SLVs. Both are/were good, but in my opinion the SLV is better made, and for the focal lengths I have, provide a slightly better view. I don't know what differences they have internally but they seem just that little bit sharper and well corrected for colour.

Harder to recommend focal lengths though, perhaps choose appropriate low, medium and high power without duplicating focal lengths should you use a Barlow at any point

[cfrommen]

Thank you both for your comments and suggestions.

[damnut]

Hi Christoph,

Good advice above. There is also a guide on SGL for ep's by The Warthog. And one by R Willey here :--http://www.swindonstargazers.com/beginners/eyepieces.htm

[mikeskor]

I'm a beginner. However, I really like my Baader Planetarium Hyperion 8 - 24 zoom with its accompanying barlow. It's contrasty, clear and convenient. I bought a Meade 5mm megawide 100 degree AFOV and I much prefer the zoom over the Meade. 

[SpaceWalker]

I'm a beginner. However, I really like my Baader Planetarium Hyperion 8 - 24 zoom with its accompanying barlow. It's contrasty, clear and convenient. I bought a Meade 5mm megawide 100 degree AFOV and I much prefer the zoom over the Meade. 

The Baader Zoom and its Barlow are pretty good at short and medium focal range up to 13mm.  IMO, you'd better get the 20-21mm FL eyepiece 100*AFOV since the Baader Zoom AFOV falls off fast up to 42* at 24mm specifically where you need wider field.