Quality of zoom eyepieces

[vulcan]

I have the 25mm eyepiece that came with my Celestron NextSter 6se and I have a 5mm Hyperion on its way. Rather than buy a number of intermediate eyepieces, I am contemplating the Hyperion III Zoom eyepiece which would seem to do all the magnifications in between at significant savings. (I am quite happy to use a zoom lens on my camera instead of individual telephotos.)

My question is in two parts:-

a. will this zoom eyepiece be on a par with individual eyepieces of the intermediate magnifications or is the compromise significant?

b. Will the Hyperion zoom at 25mm be superior or inferior to the stock Celestion 25mm that came with the scope?

TIA

[ollypenrice]

Hmmmm....

I'd describe the Hyperion as pretty good but maybe not quite as good as mid range fixed EPs. I had a look through one in September and it was better than I thought it would be. So a straight answer; as compared with a mid ranged fixed EP the compromise is there but not great and I liked the Hyperion.

I don't know the stock Celestron but if it is like a Meade 3000 Plossl then the Hyperion is comparable, I'd have thought.

Some people like to have just the right focal length EP for their target. I'm less fussy and would rather compromise on field/magnification and have a small collection of premium EPs. However, the slow f ratio of your SCT makes it fairly undemanding on EP quality, unlike a very fast Newt.

Your analogy with a zoom lens is interesting. For daytime use zooms do well but for astro imaging the primes are a clear step ahead.

Olly

[JamesM]

There are a lot of people who have written good things about the Hyperion III although there is a diminished field of view at the highest focal length compared to the rest of the zoom. The obvious question you have to ask yourself is, if the zooms were as good as the prime eyepieces then we would only have one piece of glass in our pocket. The truth is that this eyepiece is seriously good and better than most of its type and price but it will have compromises and that's a subjective decision of what you find acceptable and only you can make that decision.

Clear skies

James

[brianb]

1. I think you will find the 5mm is too much for the C6 .... it will give you a 0.5mm exit pupil i.e. 50x per inch which is more than any scope needs, 30x per inch is a more realistic top limit for magnification except for some very special purposes.

2. I've never found a zoom eyepiece to be a match for even budget "prime" (fixed focal length) eyepieces. They're always compromised in some way at some focal length settings.

The eyepieces a beginner needs are just three: one giving about 5x per inch with a wide field; one giving a high power of about 25x per inch and one giving about 12x per inch for wider views of the moon and "zooming in" on the brighter deep sky objects. Add another giving about 20x per inch for high power work when the seeing isn't so good (especially with larger apertures) and your set is complete.

[John]

Until recently I've not been particularly attracted to the mid-range zooms and I've preferred Olly's route - a number of premium eyepieces. I recently aquired a Hyperion 8-24 MK II zoom for use with my solar scope and I've also used it at night as well. The Hyperion zoom is better than I expected and works very nicely with the solar scope and for ad-hoc nightime observing - it seems at least as good as a decent plossl and is close the the fixed focal length Hyperions at the 12mm and 8mm points I feel.

It's certainly better than the eyepieces that are supplied as standard with scopes in my opinion.

I won't be selling my Naglers and Ethoi in favour of the Hyperion Zoom but I can see why it's regarded as one of the best zooms around now.

[Chris H]

The 5mm would be ok for lunar viewing,

[vulcan]

The 5mm is fine for lunar and planetary viewing. I've been looking at Jupiter and the Moon tonight and althought the sky was not as clear as I would have liked, I got excellent views of both. As both are very bright objects, and the 5mm Hyperion was performing as I expected.

[sixela]

If you want zooms that are as good as single eyepieces, the choices are limited. The best "affordable" one is the older Pentax 8-24mm one, but the newer Pentax XF zoom is almost as good, a lot cheaper, and has slightly shorter focal lengths. The Nagler zooms are also good, but they're not really for this kind of scope (the focal lengths are really short).

If that's still not good enough, you're looking at adapters and zooms from Nikon and Leica for spotting scopes, and those are going to cost quite a bit (the *adapter* from Starlight Instruments for Leica's €800 ASPH zoom costs an extra $300...).