Eyepieces for Altair Astro 102 Triplet Refractor?

[jonathan]

At the moment I have a bit of a motley crew of eyepieces, no doubt some are unsuitable for the f7 102 triplet so I'd like to ask you nice knowledgeable peeps what's good for this scope.

Here's what I have:

Celestron Plossl 25mm (came with the 8SE)

Celestron X-Cel 10mm (the previous generation)

Celestron X-Cel LX 5mm (works great in the Skywatcher 150P reflector)

Skywatcher SWA PanaView 38mm

Baader Hyperion Zoom 8 - 24mm

I don't want to go crazy on prices, there must be some medium-priced ones that are going to be pretty good.  What are the Lightwave eyepieces like in this scope?

Thanks!

[jonathan]

I should add that I'm particularly interested in seeing Jupiter and Saturn, moon, other planets if I can, and some nebula / galaxies.  A good high magnification eyepiece and a wide-field one would be good to start off with.

[ronin]

They seem to be another eyepiece we hear little about and I cannot find anyone else that sells them under another brand. They are the Longperng 68 deg eyepiece, Link, LP do have a reasonable name in astronomy. However I will caition that with they are still a Chinese produced item that is badged Altair Lightwave - also I note that the images on the Altair site do not display the wording Altair or Lightwave so maybe they are actually unbranded?

They have good eye relief but 68 degree isn't exactly wide these days, I have 4 or 5 year old 70 degree eyepieces (Antares) that were less then half the price.

Basically at £150 a piece I would want some good reviews on the items. Simply as buying one to try could be a costly exercise.

[Stu]

Not cheap, but a 3 to 6 Nagler zoom would be worth considering. I use one in my 106mm apo, f6.5 with a 690mm focal length, so quite similar spec.

With your scope, assuming 714mm f/l, it would give you a range between x119 and x238, great for most planetary observing and mid to high powers. It is par focal throughout the zoom, has reasonable eye relief and 50 degree afov. It has click stops at the mm intervals but is fine tunable to any mag to match the seeing.

Stu

[jonathan]

Been scouting around a bit and it seems that the TeleVues are the benchmarks used when testing scopes like this, so perhaps I should start saving!

I agree about the Lightwave, found a note elsewhere that they were identical to another 'brand' so looks like they are one of those generic products that comes out of China, probably not worth the £150 asking price compared to what else is out there.

I saw this though, which did get a few favourable user reviews: https://www.altairastro.com/product.php?productid=16683&cat=249&page=1

But for the money, could probably have a similar Nagler.

What's my usable smallest mm eyepiece for the 102, assuming not 100% perfect seeing conditions?  The scope is f715mm.

[John]

My Vixen ED102SS is a similar spec at F/6.5. Tele Vue's are excellent and what I use with it but other eyepieces will do well too. My highest power eyepieces for this scope are a Pentax XW 3.5mm (189x ) and a Tele Vue Radian 3mm (221x).  I find the 3mm is useful for binary stars, Saturn, Mars and the Moon but the slightly lower power is better for Jupiter.

F/7 is not too harsh on eyepieces so you don't need to spend really big bucks to get nice views 

[jonathan]

Hmm.  In your experience is there anything to choose from between having a TeleVue 3mm eyepiece and a TeleVue 3-6mm zoom eyepiece if set at the 3mm end?  If the difference isn't going to be noticeable except under perfect dark skies then that would be a good way for me to save some money.  Also, just reading the blurb about it it says the eye relief of 10mm isn't suitable for those who wear glasses, which unfortunately is me, is it really a big deal?  Maybe it's why some of my eyepieces don't work very well for me!

I like the look of the TeleVue Radian 3mm, which is cheaper than I expected and about what I would be prepared to pay for what should be one-off purchases.  So what's the practical difference going to be for me between a 3.5mm Nagler and a 3mm Radian?

[John]

I've owned all those eyepieces, the 3-6 zoom twice ..... but not all at the same time !

I'm a little reluctant to compare things that are so close from memories of how they performed. I think Alan Potts currently has a 3-6 zoom and a 3mm Radian so might be able to chip in on the basis of a direct comparison.

They are all excellent eyepieces, obviously. My gut feeling is that the Pentax XW's are the best of the bunch and I certainly found that a Pentax XW 10mm was just a wee bit better than a 9mm T6 Nagler so it's conceivable that it would be the same at the 3.5mm focal length. When I say "best" I really mean control of light scatter around bright objects, ability to show very subtle contrast differences in planetary features and overall sharpness. Any differences between them are emphasised more when seeing conditions are excellent (not dark necessarily, but steady) as you say, however, even on so so nights you often get pockets of excellent seeing so having that slight edge is of value. 

The 3-6 zoom makes a lot of sense and performs excellently but I just could not get on with the two I owned. Maybe it's the 50 degree FoV and the 10mm of eye relief ?. Most others that have tried them love them to bits though so I'm in a minority here I think. 

I'm a late comer to the Radian design as I've only used them in the past year. The 4mm and 3mm I currently have are really good though and sit alongside the XW's quite happily in performance terms, for me at least. 

Take lots of soundings though Jonathan. Eyepieces are such a personal thing that I suspect everybody is going to reach a slightly different conclusion on which they prefer

[Stu]

I use the nag zoom when travelling as it covers so many options in a small package. For the money it's great, I don't wear glasses to observe so the eye relief is fine.

I have arrange of eps at this sort of focal length, and I do think they have a small advantage over the zoom. I have 3 & 4mm Radian, 3.5t6 and 4.5mm Delos. The Delos is very nice and has comfortable eye relief. The 3.5mm might make sense for you as a high power. I have the 5 & 7mm XW's and they are also lovely eps, not a lot in it with the Delos.

Stu

[jonathan]

OK, if you could own one high power (mainly for planets and the moon) and one wide field for the 102 f715 refractor, which would you choose?

It may well be that I start by saving up for a high power first as that has always been the most critical for me, lower mag eyepieces seem less sensitive to seeing conditions so I could live with my lesser eyepieces for longer.

I read an interesting comment while I was reading various forum posts on these eyepieces and such, it mentioned about astigmatism and how stars sometimes look like comets / flares.  Until reading this I thought it was just my eyes, but if it's actually an artefact of lower quality eyepieces then I'm optimistic that I may be able to eliminate that effect with a high quality eyepiece or two.  It seems that I need to line up my eyeball precisely to the star I want to see without the flare, all other stars around get the flare / comet look; perhaps my eyes are just more sensitive to this kind of artefact, or perhaps it is some stray light from nearby or my local seeing conditions that all contribute to it.  If high quality glass eliminates this across the entire field then it will be worth the money for me.

[John]

With a 102mm 714mm focal length scope I'd probably go for a 4mm (179x) if I had to just have one high power eyepiece. In my case that would be the 4mm Radian.

For the lower power I think I'd go for something like a 17mm Nagler T4 which would be very sharp, have comfortable eye relief (for an UWA) and show nearly 2 degrees of sky at 42x.

Not perfect I'm sure but the best I can come up with at short notice ! 

[jonathan]

I found a very interesting page about abberations, it describes what I see pretty well and that is coma.  I'm not sure if this is in my eye or in the eyepiece, but having very high quality eyepieces should at least go a long way to eliminate the hardware from blame; if it's in my eye, there is nothing anyone can do about it.

http://www.umich.edu/~lowbrows/reflections/2007/dscobel.27.html

So my shopping list currently looks like this:

3 or 4mm Radian TeleVue, probably 4mm to forgive some of my local seeing condition imperfections.

17mm Nagler TeleVue.

I shall have to see if I can find a visual guide to what each of these eyepieces will typically show.

[Stu]

The 4mm would be a good choice for regular use at high power, even going to 3.5mm would probably take you to a level you don't use so often.

Plenty of choice for widefield but 17t4 would be great as suggested, nice near 2 degree fov with a good exit pupil.

Stu

[Stu]

Here are two examples for the 17t4 in your scope...

and the 4mm Radian with Jupiter

Stu

[John]

I was using the 4mm Radian on Jupiter with my 4" F/6.5 (165x) last night and the image of the planet was very crisp and contrasty. It was decent at higher powers too but the 4mm was showing the clearest detail in the belts despite the slightly smaller image scale. 

[jonathan]

Excellent info and pictures, thanks chaps!  I'm sold on those two eyepieces..  they are next year's shopping list!

[Joe G]

I have the same dilemma trying to find the ideal high magnification eyepiece for my ED100 F/9 scope. There are so many choices out there. I am seriously thinking of the Baarder zoom/ barlow combi or the Naggler 3-6zoom. As you have the zoom already the barlow would be a relatively cost effective way of finding the best viewing mag for each target  & as a stop gap till you make your final selection

[jonathan]

I get the feeling that the Baader zoom will be in a slightly different league to the Nagler and Radian.  I haven't yet tried the Baader in the 102 f7 as it's currently living in my Lunt LS60 solar scope case (I'm too lazy to get it out, and also forgetful), where works really well.  Will have to give it a go soon, may well end up buying the matching barlow but mainly for use with the 150P reflector and solar scope, doubt it would be useful for the 8SE.

The only thing that puts me off the TV zoom is the low eye relief, which is apparently no good for glasses wearers.  I could probably observe without glasses but I prefer to keep them on as looking up at the sky I see just a mass blur of spots without them.

[Joves]

A couple of nights ago, I was viewing Jupiter with 6mm Radian, 6mm Ethos and 3-6mm zoom. You wouldn't go too far wrong with either. The Radian definitely produced a "whiter" image than the others, but was possibly the most comfortable to use. The 3-6mm zoom certainly held its own at the identical 6mm focal length though, plus across the entire range it provides. Was also very comfortable. If you're wanting more options with the one EP, I wouldn't hesitate recommending this. That's if the budget allows, of course. Otherwise, I'm sure you'd be very happy with the Radian. The Ethos is obviously more expensive, but was good for comparisons sake.

[jonathan]

Think after long deliberation and saving I'm going to go with the Pentax XW 3.5, it may not have the same edge as a TeleVue but I doubt my eyes or seeing conditions could spot the difference and the lack of eye relief also puts me off them. Might also be tempted by the 20mm after some more saving.

My other iPad is an iMac.

[John]

Think after long deliberation and saving I'm going to go with the Pentax XW 3.5, it may not have the same edge as a TeleVue but I doubt my eyes or seeing conditions could spot the difference and the lack of eye relief also puts me off them. Might also be tempted by the 20mm after some more saving.

My other iPad is an iMac.

I have a Pentax XW 3.5mm and it's wonderfully sharp and contrasty in my scopes, including the 12" F/5.3 dob when conditions are very kind. The XW's don't give anything away to any Tele Vue eyepiece that I've used and I've used most of the TV ranges.

I feel that the XW's are a touch better than the T6 Naglers, the 3-6 Zoom and the Radians though it's all very close. The Delos (Deloi ?) seem to be virtually identical to the XW's in performance.

[kev]

Just a thought re your glasses. The higher the mag tge smaller the exit pupil so the less ant eye lens abberations affect vision.

As for me i tend to use my 2.5x powermate with a medium power eyepiece.

Sent from my iPhone using Tapatalk

[avtaram]

I have the Baader Zoom + Barlow combination that works really well in all my scopes and gives great views.

Recently I've been comparing all my eyepieces using the 120ed and came to the conclusion that all I really needed was the 38mm Panaview for wide field and the Baader Zoom + Barlow combo for the rest.

Avtar