Zoom eyepiece

[KeithP22]

Hi guys, I have a StarTravel-102 and an 8 inch dob. I was thinking of buying a zoom eyepiece. I've been looking at OVL HYPERFLEX 7E 7.2 - 21.5MM ZOOM EYEPIECE. Does anyone have any experience of this eyepiece. Would love to hear all your comments. Thanks in advance. Keith.

[Shimrod]

6 minutes ago, KeithP22 said:

Hi guys, I have a StarTravel-102 and an 8 inch dob. I was thinking of buying a zoom eyepiece. I've been looking at OVL HYPERFLEX 7E 7.2 - 21.5MM ZOOM EYEPIECE. Does anyone have any experience of this eyepiece. Would love to hear all your comments. Thanks in advance. Keith.

There's a recent user review and comparison with some other eyepieces here:  https://stargazerslounge.com/topic/362468-hyperflex-7e1-seben-8-24-zoom-bco-18-10-compared/?tab=comments#comment-3950434

[michael.h.f.wilkinson]

I think the Hyperflex is the same EP as the Lunt zoom EP of the same specs. I had the latter for a while, and the views through it were good, but the eye relief was just a touch short for me with my glasses. I now have the William Optics Zoom II 7.5-22.5 mm which is very similar, but has an eye relief of 18.5-19 mm, which is a lot more comfortable for me. It is no longer sold by WO, but clones are still around (NOT the Seben of the same specs, but Opticstar and Omegon have good ones). If you don't need to wear glasses, by all means go for the Hyperflex

 

[KeithP22]

16 minutes ago, michael.h.f.wilkinson said:

I think the Hyperflex is the same EP as the Lunt zoom EP of the same specs. I had the latter for a while, and the views through it were good, but the eye relief was just a touch short for me with my glasses. I now have the William Optics Zoom II 7.5-22.5 mm which is very similar, but has an eye relief of 18.5-19 mm, which is a lot more comfortable for me. It is no longer sold by WO, but clones are still around (NOT the Seben of the same specs, but Opticstar and Omegon have good ones). If you don't need to wear glasses, by all means go for the Hyperflex

 

I do wear glasses but I don’t use them when observing. I can get a clear view by using the focus.

[michael.h.f.wilkinson]

6 minutes ago, KeithP22 said:

I do wear glasses but I don’t use them when observing. I can get a clear view by using the focus.

I have cylindrical astigmatism, so need to keep them on. If you don't have that problem, short eye relief is not an issue

[Steve Clay]

I have the Hyperflex zoom and for the price it's very good. Only requires slight refocus between the  range.  I wear glasses but don't use them at the ep.

[MrFreeze]

I have the Hyperflex, and it is a really stunning eyepiece. I also have the Celestron 8-24 zoom which is pretty good, but the Hyperflex is noticeably clearer. The Hyperflex also seems to 'fit' my face better than the Celestron if that makes any sense. With the Hyperflex you are just 'there' as opposed to looking 'through' an eyepiece.

David

[Pixies]

I have the Baader Hyperion Zoom, which I love. Just bear in mind that with these zoom eyepieces, the field-of-view decreases as the focal length increases. I.e. the view narrows as you zoom out.

If you need to use a wide-field EP as a finder, the zoom won't be much use for this. If you are coming from a position of not having any other EPs, you might need to consider a separate wide-field one.

[Zermelo]

I have that one, I find it very useful and I've been impressed with the performance. The FOV is narrower than some of the wider field fixed EPs, and as noted above it reduces as you zoom out, which is the opposite of what you might expect. There is another Hyperflex zoom with a slightly longer range, though I believe opinion was that the 7.2-21mm was slightly superior.

[chiltonstar]

For the price, it is excellent. I use it with a 180 Mak (which is eyepiece-tolerant because of long focal length) and it gives views nearly as sharp as prime orthos.

Chris

[John]

Another fan of the 7.2 - 21.5mm zoom here. I use mine a lot and often with a Baader 2.25x barlow to give a high power 9.5mm - 3.2mm zoom which is very useful in my scopes but perhaps not so much in a mak-cassegrain 180 ?

 

 

Edited October 21, 2020 by John

[globular]

+1 fan of 7.2 - 21.5mm.  Loving it on Mars where I can dial in to the best viewing magnification and where the narrow FOV doesn't matter.

[johninderby]

I have used a TS version of the Hyperflex zoom for a while and find it to be a very good zoom.

Have been testing the new Svbony 10-30 zoom and really impressed by how comfortable it is to use. Great views and just easy to look through..Just realised I haven’t used the TS zoom since getting the new zoom. 🤔

[John]

8 minutes ago, johninderby said:

I have used a TS version of the Hyperflex zoom for a while and find it to be a very good zoom.

Have been testing the new Svbony 10-30 zoom and really impressed by how comfortable it is to use. Great views and just easy to look through..Just realised I haven’t used the TS zoom since getting the new zoom. 🤔

There you go OP - a nicely kept Hyperflex zoom might be available shortly

How does the AFoV across the range compare John ?

 

Edited October 21, 2020 by John

[johninderby]

47 minutes ago, John said:

There you go OP - a nicely kept Hyperflex zoom might be available shortly

How does the AFoV across the range compare John ?

 

The TS is 40 to 53 degrees and the Svbony is 33 to 51 degrees so slightly narrower. Has a claimed eye releif of 17 to 18.5mm.

Edited October 21, 2020 by johninderby

[DaveL59]

I've not tried the other zooms so can't compare against other brands but I recently got the svbony sv171 huge 8-24mm zoom and find it very good and was at a bargain price via their official store on Ali. Only issues may be getting it clamped as it overhangs the locking screw in some focusers and of course the weight may be a problem in some setups. 

[KeithP22]

Thanks for the comments guys. So would this eyepiece be okay to use in both the StarTravel-102  and my 8-inch dob. 

[bomberbaz]

Well you ST102 has a focal length of F510 I think and assuming your 8" dob is F6 = F1200 then yes, it would be a very good match for both the scopes. 

[procky1845]

I just bought the Hyperflex Zoom last month and have used it with great success with my 8" dob and 5" mak.

Really good for the money, would recommend. Also Barlow's well.

Lee

[KeithP22]

9 hours ago, procky1845 said:

I just bought the Hyperflex Zoom last month and have used it with great success with my 8" dob and 5" mak.

Really good for the money, would recommend. Also Barlow's well.

Lee

Thanks Lee, I bought one the other day. Wife says I can't have it till Christmas. I think i might have to persuade her. 

[JeremyS]

20 minutes ago, KeithP22 said:

Thanks Lee, I bought one the other day. Wife says I can't have it till Christmas. I think i might have to persuade her. 

You mean you don’t know where she stashes you’re pressies? 🙂

[KeithP22]

23 hours ago, JeremyS said:

You mean you don’t know where she stashes you’re pressies? 🙂

😂😂

[Second Time Around]

I've tried out 4 different zooms and kept 2.  These are the Baader 8-24mm that's more expensive than those mentioned so far, and the very inexpensive Svbony 7-21mm.  The Svbony is apparently identical to the Orion E-series but at an even lower price. 

The Baader is a little better off axis at f/6 and has a larger field of view than the Svbony.  However the Svbony is much smaller and lighter, and exceptional value for money (about £45).  I bought the Svbony because of the excellent reviews it had on Cloudy Nights, and am happy to recommend it myself.  

Svbony also sell 8-24 and 10-30mm models, but again I haven't seen these.  Both are much bigger and heavier than the 7-21mm Svbony.  Additionally the 10-30mm has a particularly small apparent field of view, plus fewer elements and so is unlikely to be as good.

The ones I didn't keep were firstly a Celestron (from a terrestial scope rather than the usual astro model.  This was because it didn't have a filter thread).  Secondly a clone of the Hyperflex 9-27mm.  There was nothing wrong with the Hyperflex, but both the Baader and the Svbony 7-21mm can be adapted to take a Televue Dioptrx adapter to correct the astigmatism in my eyes.  I gather the astro model of the Celestron 8-24mm has a T thread that a Dioptrx will also fit.