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Planetary eyepieces for short refractor


Adrian_P

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Hi there

Apologies for re-treading what is pretty familiar ground but I’d like to seek your views on eyepieces. First, some background. I’ve got an 80mm refractor - a William Optics Zenithstar 80 fluorite doublet – with a modest collection of plossl eyepieces down to 7.5mm. The plossls are OK down to about the 10mm mark but, below that, suffer from pretty poor eye relief, and the feeling of looking through a drinking straw.

What I’m looking for is a shorter focal length eyepiece, maybe around the 3 to 5mm mark suitable for planetary use. OK, I realise that an 80mm refractor with a 555mm focal length is never going to be a great planetary scope (and it’s not why I bought it) but who doesn’t like getting decent views of Jupiter or Saturn when the opportunity presents itself? So this is the requirement. A short fl eyepiece, suitable for a short fl refractor, with better eye relief and comfort than a plossl. If I could get a wider field of view, then so much the better. Oh, and probably no more than about £150.

I’ve looked around and the WO planetary series looks like a decent option. But then again, the WO UWAN is tempting; almost twice the price but a lot more FoV. And then the Meade 5000 series wide fields are on offer at the moment and seem like good value.

So grateful for any help in spend my money.

Thanks.

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Hi Adrian. A TV Radian fits your requirements, apart from price, more than your £150. If you keep looking, you could be lucky on the used market at around £100.

Radians have 20mm eyerelief, 60 degree apparent field, and sharp to the edge in most scopes. They are being phased out, but are still listed in the shorter focal lengths you are looking for, 3mm, 4mm, 5mm at Telescope House and Green Witch Cambridge.

Regards, Ed.

Edit : welcome from a fellow Essex member (Southend on Sea)

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Have you considered the TMB planetary (clones). They have a good rep. I rather liked my Radians (only had the 8 and the 10, so cannot comment on the 3mm), but the Pentax XWs beat them. Not cheap, but ortho-like in performance over a 72 deg field. On the other hand, the Vixen NLVs are very good, as were the older LVs (they are still around). These have long eye relief (longer than your typical UWA), and sufficient FOV for planetary viewing. If you want more FOV, the LVW series of Vixen get a very good press as well.

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If a wider view is of interest the 4mm WO uwan or the equivalent nirvanas, if your scope is manual the 80 deg field will be welcome and eye relief will be similar to a 15mm plossl ok but not great.

I had a 4 NLV, sold on here yesterday and they are very good - long relief, sharp but only a plossl size field of view. It might be worth while looking at Astro buy and sell if you don't mind buying second hand - see Damo link.

andrew

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Sky's the Limit have the TMB clones, 4mm and 3.2mm.

TV Radians go down to much the same focal lengths but are significantly more.

Telescsope Service do their own brand of planetary's that again are very TMB like but in this case they more resemble the real TMB's and from one comment by someone they perfom pretty close to the real TMB's.

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at a little over budget is my suggestion (why did I say that like Yoda?), a used TV 6-3mm Nagler zoom. This will provide excellent views at a range of magnifications and is ideal for your purpose. eye relief is better than a 10mm plossl and AFOV (about) the same. not cheap but superb.

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The Nagler 3-6mm zoom is tailor made for this type of use as Shane says.

I use 5mm and 3.5mm Pentax XW's with my 663mm focal length Vixen ED102 refractor and they are superb. Sandwiched between them is a Nirvana 4mm which does surprisingly well against the more costly XW's.

Another way to get high powers in a fast scope would be to use a quality barlow / multiplier such as the Tele Vue Powermate 2.5x. The Powermates really are invisible apart from the extra magnification and can be bought well within your budget.

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The problem with a specific used item is it may not crop up for 6 months, and then you have to be the one that sks for it first, that is fine if you do not need or want one with any urgency but otherwise not a great deal of use.

Adrian has 2 posts, so that rules out SGL classifieds for some time.

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John has sort of taken the wind from my sales as I was going to tick the box of the 4mm Nirvana which has many fans. I personally like the 4mm and 5mm Radians but they are a little more. Telescope House offered me a 3mm last week for 171 pounds so it is not too far away from your maximumspend.

I went for the 6mm Delos which I will powermate to 3mm. This is a F/L that will not get a great deal of use so I thought it was a bit over the top even for me.

Alan.

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Many thanks to all who responded (especially from Ed, a fellow Essex member!)

Oh man, this is a tougher choice than I ever thought it would be! I suppose that I'm really looking for a couple of focal lengths at this end of things; maybe a 3mm for nights of really good seeing and something a bit longer when conditions aren't so great. So I'm already looking at doubling my original budget, albeit over time, to around the £300 mark at least. But if I've got to shell out £300, then why not do it in one hit and just get the 3-6mm Nagler zoom which seems to be custom made for me (as Shane and John have said)? I don't recall ever hearing anything bad about Tele View gear in general and cannot find a single review that isn't glowing about the Nagler zoom. That's the way I'm definitely leaning at the moment although the 10mm eye relief is a bit of a worry. I'm not really a glasses wearer, although having mild astigmatism I do use a pair occasionally for computer use, but it looks like the eye relief of the Nagler zoom is really not enough to accommodate them should I need them. But then one last thought; does anyone know if the Nagler zoom is compatible with the Dioptrx? If so, that would probably seal it for me.

Once again, many thanks for your help on this (indeed, helping me spend £150 more on eyepieces than I was planning to!)

Adrian

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I'd recommend either a used LVW or a used Radian. I used to use a 3mm Radian as a planetary eyepiece for my SV80s.

It was sharp and performed wonderfully. The Radian colour was a bit warmer than my other eyepieces. The contrast and resolution were good and the internal reflection was well controlled. The only reason I sold it was because I bought a 2.5 XO and I can't justify keeping two expensive planetary eyepiece that I rarely use (I usually use CAT for planets).

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At this end of the field you are not going to get a bad eyepiece, wht not try to stretch out foe the 3-6mm Nagler zoom that Shame saw, he has one and talks very highly of it.

Or the 3mm Radian, These really are as about as good as it gets after this it is just down to the person using it.

Alan.

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  • 2 weeks later...

Hi all

Many thanks for the advice I received. Unfortunately, I couldn't go with every recommendation so, applying a little bit of instinct, I decided on the Nagler zoom. In fact, I bought the one that Shane linked to above. Well, the EP arrived during the week and, being away at the time, this is the first chance I've had to get my hands on it. It's beautiful! The way the zoom control works; the feeling of small size, light weight but real heft; it's just pure quality. And trying it out on a terrestrial target, I think I was worrying unnecessarily about eye relief which seems quite comfortable.

Well it's late afternoon and, as the clouds start rolling in following a lovely sunny day here in Essex, I can't wait to try it out for real! It just probably won't be this evening but I live in hope.

So, once again, thanks for all the advice. I'll probably be back again in the future now that the TV bug seems to have bitten - I could probably do with a nice wide field 20mm at some point!

Adrian

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