Zoom eyepieces, What's your take

[Jamie]

I am looking at zoom eyepieces and was wondering what (people that have used/owned them) opinions of them are.

I do understand that they won't be as good as a single eyepiece.

There is also the claim that they have advanced so much recently that the difference is negligible.

Your thoughts please.....

[GazOC]

I have the Hyperion zoom and use it a for quick looks when a take my ED120 out on an alt/az. Its a very good eyepiece but it doesn't come close to replacing my "proper" Hyperions when I'm out for the night with my 14 "f4.5 Dob (the focal ratio does the zoom no favours).

[russ]

Hi Jamie,

I've had two zoom eyepieces, both at the same time. Had the Skywatcher 8-24 for lower powers and the Speers 5-8 for high power. They were opposite ends of the zoom market.

The Speers was faultless and possibly one of the best zooms money can buy (even taking into account the Nagler 3-6). A constant 80deg FOV throughtout its zoom range and the optical quality as good as the fixed length models. Only it's sheer size and some in-focus issues counted against it.

The Skywatcher was just a budget jobbie and was merely okay. FOV was very narrow at the low power end. Colour correction was a bit iffy and there was a bit of light scatter. For £30 it was okay. But a 40deg AFOV at 24mm was too little for me.

[brianb]

I enjoy having as little glass as possible between me & the target. I do not like zoom eyepieces, extra glass scatters light reducing contrast, as well as the aberrations which tend to be more severe than ordinary eyepieces in the same price bracket. The ones I've seen are less convenient than they might be, too, they always seem to need refocusing after adjusting the zoom.

[dweller25]

I have the Televue 8-24mm zoom. It is just as as sharp as my TV plossls and KK Orthoscopics but has more eye relief and a wider FOV.

I use the zoom in an F/6 newt and F/8 refractors which may help.

[AndyH]

I had one of the very nice William Optics 7.5-22.5 zooms. The ones that look like their Uwan line. Was nice but orthos completely blew it away at the high power end and most zooms are a waste of time at low power. Terribly narrow fov.

I reckon the best zooms are the small ranged ones. eg: Televue 2-4, 3-6/ Antares Speers 5-8, 8.5-12. Got the former, of the Televue and Speers. Superb.

I only use a 32mm uwa and the 5-8 speers on my fl700 scope.

Cheers,

Andy.

[Phil73805]

I have an unmarked (no manufacturer mark) 7-21mm zoom eyepiece that I use for my PST. It works flawlessly and provides pin sharp views through the 'scope.

[Mark at Beaufort]

Hello Jamie.

I have the Hyperion zoom which is a very good EP. I don't think there is much difference between the zoom and the individual Hyperions. I had the 5mm, 8mm, 17mm and 24mm so I was able to compare them. The only disadvantage with the Hyperion Zoom is the FOV at 24mm which is a bit restricted.

Anyway Jamie when we meet up in 2 weeks I will bring the Zoom with me and you can try it on whatever scope you want. Added to which you have the 6" frac to play with.

See you on the 15th.

Mark

[Jamie]

Cheers Mark...

Keep the comments coming guys....

[davew]

Hi Jamie,

I've got an old Leica zoom. They have reasonable write ups on CN.

I got it from a local birding shop who let me try it out first. A bit important that. Try before you buy if you can. ( The actual eye piece )

Some of the cons don't bother me much. Refocusing ( most noticable when zooming IN ) is still less bother than changing eyepieces. The FOV is usually narrow at the wide end. I don't go all the way out plus I'm used to using plossl eye pieces. At the short end the view is quite wide. The eye relief changes on mine. It does when I change to other eye pieces too. Surprise

I've used it in native f4.8 and f8 scopes. In the f8 the views are almost impossible for me to tell apart from my other eye pieces. At f4.8, very close at most points in the zoom range but a Newt does tend to tax any zoom I think.

The extra glass also doesn't bother me. A good zoom has good coatings but it may not be the very best when used after a Barlow ( or two ) on planets. Still holds up well though. Hitting the sweet spot for mag is very simple.

Dave.

[davew]

Hi again,

Just had a nice cuppa and a think about how I use mine.

If you are like me ! after I set up I like to have a swing round and do the " Usual suspects ". A zoom is almost made for that alone. It's also very good for checking out things like " Uh, what's that ?".

On the other hand, if you are not like me and want to sit and tease out the very last drop of detail over a 30 minute period, go away, think and then return for another 10 mins or so, then don't use the zoom.

Dave

[Andrew*]

A zoom eyepiece by its nature has to make compromises, but in my experiences these have never out-weighed the benefits involved: many eyepieces in one with a fine-tunable range of focal lengths to perfectly suit your target, and no changing eyepieces needed. I've not felt the need to have fixed focal length eyepieces overlapping the zoom range, with one exception.

The zooms I've tried:

- 8.5-12mm Antares Speers-WALER. This is the best, but it particularly tricky to get hold of. I got mine from Canada. It has a constant 82° FOV and is truly excellent optically, even in fast scopes. Drawbacks are its notorious need of in-focus (I need to switch to 1.25" diagonal in my ED scopes, and I needed to get a low profile focuser for the 16" Lightbridge). You are more than welcome to have use of this for SGL5.

- 3-6mm Nagler zoom. When I had it, it was the only high power eyepiece I used. It only has a 50° FOV, and quite tight eye relief, but much better than that of orthos. Optically it was every bit as good as an ortho - it only has 5 elements. The best thing is that it is perfectly parfocal throughout the zoom range. Also very small and light. I'd choose this over 4 premium orthos any day.

- 8-24mm Hyperion zoom. While this was the least "accomplished" of the three, it was alos the cheapest! It also offers a larger range than the others. Eye relief was good, FOV was good for much of the zoom range. I did actually use a 20mm SWA for more serious low-medium power use, but only to make up for the small FOV at the higher focal lengths in the zoom. It worked acceptably at f/5 too. Extremely versatile and can dramatically lighten up your eyepiece collection!

So a big thumbs up to zooms from me. I'm sure with time we will see better and better zooms on the market, and primes will see the same decline they saw in the photography market, although they will always hold a top spot for the more discerning user.

Andrew

[John]

The only zoom I have tried is the Tele Vue Nagler 3-6mm zoom which is excellent - I'm on my 2nd one of those

I've not really been attracted to zooms otherwise because I generally like wide or ultra wide views - the Speers-WALER was tempting but the in-focus issues rather put me off it.

[cdd2455]

I have a pair of TV Click Stop Zoom eyepieces sitting unused for the last 8 mnths since I purchased 18 and 12.5 BGO's for my Denk Binoviewer.

In my binoviewer during day time Halpha use, the TV zooms were prone to internal reflections & ghosts, gave the sun a curious 50p piece shape at the 24mm setting but worst of all, I found it was difficult to merge the images, due perhaps to the safety undercuts being where the denk collet grips the eyepiece and also perhaps to the length of the eyepiece. I'll get round to selling them one day.

For binoviewer use, I'll eventually find some mid 20's simple eyepieces to fill the gap between the BGO 18mm and the 32mm plossls.

Best Regards

Carl

[gary1968]

Jamie, I have a cheapo Zoom, 8 ~ 24mm IIRC, I think I bought it from Astronomica. Anyway, it works ok, but, FOV seems to work opposite with this EP compared with normal EP's. I.E. as you get the EP to longer focal lengths the FOV gets smaller. Its a bit annoying and for that reason I dont use it much.

I have tried it with my ED80 and the 6"sct I just sold and as I say didn't like it. It might be fine with a faster newt which I will try soon when I eventually decide which one to buy.

HTH,

Gary

[Macavity]

I had a Vixen/Teleview 8-24 Zoom once. I found it best suited to create a TRULY portable setup with a small MAK. It was by far the "classiest" eyepiece I've had, but it also contained transparent dust-like particles(!). Fortunately I got rid of these, by a judicious thump or three on the setee! I sense [some] Zooms are, by their nature not quite "hermetic"? For me, it suffered too, from that weird phenomena, dubbed "ring of fire" (at the periphery) - A sort of orange-yellow blackout, making eye placement a bit tricky! But then I believe even Naglers aren't intended for daylight use?

[John]

... dubbed "ring of fire" (at the periphery) - A sort of orange-yellow blackout, making eye placement a bit tricky! But then I believe even Naglers aren't intended for daylight use?

Some Naglers are better than others in daylight. The Type 5's show the "ring of fire" effect which is actually a fine blueish (to my eyes) rim of light around the edge of the field stop. Only visible in daylight and slightly when viewing the moon. I've noticed the same effect in a 16mm UWAN as well.

The 3-6mm Nagler zoom does not show the effect.

[Jarndyce]

I'm reasonably pleased with my Hyperion zoom. Although the FOV at 24mm is not great, it's generally convenient and I end up using it a lot. By that measure, it's been good value.

Is it as good as the equivalent fixed focus Hyperions? Probably not. But then it's only the cost of two of these EPs.

[digitaldave]

Zooms better be good... I just ordered a Nagler 3-6 Zoom .

[Macavity]

Is it as good as the equivalent fixed focus Hyperions? Probably not. But then it's only the cost of two of these EPs.

Good point. ISTR the TFoV of the 24mm setting was equivalent to a fixed focus 17mm - So it covers, at least, the range of the 8mm and 13mm, at reasonable AFoV. One reviewer compared it very favourably with the 8mm too. For those reasons, I am tempted.

Amusing aside: I see someone contrived to attach(?) a fixed Hype nosepiece (Smythe lense / whatever) to get a shorter focal length zoom. But then I do sometimes add the "unscrewable part" of my Skywatcher Barlow to standard Hypes for ~1.5x... Who knows?

[Stardust]

I've got TV3-6 which is my only high power eyepiece and its superb.

I had a TV8-24 which was ok but a lot of money tied up in something a I didn't use very much.

I did pick up a SW 8-24 for thirty something quid which isn't bad for the price. Not parfocal which is annoying, nor was the TV either. Taking it away next week, the thinking behind it is for a holiday package with a Skymax 90 that I picked up last week for £25.

[cootuk]

I've just bought one of the cheaper Seben type 8-24mm zooms.

For a beginner it is pretty good, mine being parfocal. A x2 barlow with it gives a massive spread of magnifications with decent eye relief.

I still have a decent 32mm lens for widefield.

The practicality of one lens for a learner is overwhelming.

It resolved Castor easily so can't be complete rubbish - too much cloud recently to really push it to the limits.

[Breakintheclouds]

I tried a Hyperion zoom in my 200P at SGL5 and was really quite impressed. It gave great views of the moon, with no visible distortion, and was also good when I viewed M13. From what I'd been led to believe there would be distortion all over the place, but it really wasn't bad at all.

[Jarndyce]

Glad you liked it, Ian! The views of M13 on your well-collimated newt were impressive. :-)

[step_hen]

I have a hyperion zoom and am quite impressed! is it good enough to replace individual ep's? well no, but then it is the convenience factor that appeals so much. i took it to france last week with my Mak and had some great views. my biggest gripes are the lack of fov at 24mm, and the fact it isnt parfocal, no matter what it says on the box!

Stephen