Cheap but good Zoom Eyepiece

[Big_Daz]

So my partner asked me what I would like for Christmas.

I told her I would like some BST's to which she swore at me when she saw the price, I tried to explain that they were good quality and reasonably priced compared to other eyepieces but to no avail, I did however spot a really cheap seben zoom eyepiece though for £20.59 on the bay and told her to get me that as a "stocking filler" thinking, if it was rubbish, my son could use it on his cheapy scope.

Firstly it was from Germany so I was expecting it to take a couple of weeks for delivery, It turned up within a week. Secondly I thought for the price it may have been poor quality and/or plastic, How wrong was I. It felt solid and looked good with coated lens and a bolt type protective receptacle. It fully zooms between 7.5mm - 22.5mm and is very smooth to adjust "no clickstops" also the eyepiece has a twist up eye cup like the BST's.

I had to have an hour with it last night before she put it away for Christmas  and although the viewing wasn't great the moon was just fantastic at 22.5mm but after zooming in to 7.5mm with slight adjustment to focus it was crystal clear showing loads of detail in the terminator. Jupiter viewing was not as good, too much misty cloud but could definitely make out two bands and three moons even at the edge of view with no distortion.

I did try my 2x barlow with it and with Moon at 7.5mm + barlow, it felt like I was on the Moon, it was a little difficult to position my eye at times, probably because of the barlow, but on Jupiter I felt it was better without the barlow.

In my very amateur opinion this eyepiece is great value for money for a beginner and better quality than the standard 10mm that came with my scope.  

[Moonshane]

sounds like a bargain. most eyepieces, zooms included, will provide pretty reasonable views in most scopes. I like Televue but there's truly not a massive difference between them and cheaper options. the differences are often there but subtle and you can certainly enjoy great views with cheaper options. it's a personal decision in the end as to whether the expense is worth it and you seem quite happy currently so enjoy!

[knobby]

I've heard someone else mentioning the same zoom and liking it, just cant remember who.

merry Christmas :-)

[Peter Drew]

I have the expensive 8mm-24mm version Seben (£49 ) This gives excellent performance at F10 and is used without exception on my Ha solar scopes. As with single eyepieces, optics "faster" than F6 require a more sophisicated zoom for good results. 

[Pig]

I too have heard this is a good zoom eyepiece, I am sure there was a thread in the not to distance past

Enjoy your new eyepiece, zooms are very handy

[Reeny]

Ordered for my cheapy 700/76 reflector

The 3" scope works well with the Revelation plossls, but I need them for the 8" dob.

Also - the Zoom will save me swapping the moon filter over onto the next eyepiece again and again and again.

I already have a brand new moon filter with mashed up threads.

This way I can get set up, use one eyepiece, and leave it alone.

[Big_Daz]

Ordered for my cheapy 700/76 reflector

The 3" scope works well with the Revelation plossls, but I need them for the 8" dob.

Also - the Zoom will save me swapping the moon filter over onto the next eyepiece again and again and again.

I already have a brand new moon filter with mashed up threads.

This way I can get set up, use one eyepiece, and leave it alone.

Please let me know what you think to it when it turns up Reeny.

I'm not sure that the other reviews were for this zoom eyepiece, I think it they may have been for the more expensive £50 seben 8mm - 24mm zoom eyepiece like this one.

[John]

The economy 8-24 zooms (Seben included) are better than the 7-21 ones.  I had a Seben 8-24 for a short while and though it not bad at all in the 8mm - 15mm range. It got a bit mushy and narrow beyond that. 

FWIW I reckon most of these are made in the same factory and just rebranded as Seben, Skywatcher, etc, etc. 

[Big_Daz]

This is what the 7.5-22.5mm zoom looks like

I have not seen any similar to this one before where as the 8-24mm does look like the skywatcher one, and like I said for £20 I think it is a good option for a beginner to give more of a range than the standard EP's or someone that uses a travelscope of some sort. I understand, that for some, individual EP's would be better for quality and eye relief ect, but for someone like me with little funding and minimal space for transporting I think it is a great little accessory. I have to transport my scope in a motorcycle helmet box so this should minimise the amount of kit I have to carry also.

[Big_Daz]

Has anyone owned one of these type before? If so I would love to hear your opinions. Thank you.

[keithatrochdale]

It looks very similar to one I got from TS Services for £100plus, which works well.

I also have a 8-24 Seben and it works well too.

[LukeSkywatcher]

I have the Hyperion 8-24mm. Its expensive. Ive heard good things about the Seben.

[Big_Daz]

I have the Hyperion 8-24mm. Its expensive. Ive heard good things about the Seben.

I have also heard good reviews on the 8-24mm seben zoom but nothing on the 7.5-22.5mm seben zoom. That Hyperion zoom looks a lot more substantial than the Seben one, nice.

[paulastro]

I have an excellent zoom eyepiece made by Celestron.  It's not one of the usual Celestron zooms, it's the one supplied with their Regal range of spotting scopes.  The eyepiece is supplied with all the three spotters in this range and is marked with the magnification it gives on each of the scopes - different with each one due to the different focal lengths of the scopes of course.  It actually is 8-24 as far as I can tell.  In my view, it's much better than the many other zooms costing up to £200.  I asked at a supplier of the scopes if the eyepiece was available separately and was told it isn't.  So, I'm afraid if anyone wants one, they will have to buy a spotting telescope as well!

[bambuko]

Mine has arrived today (very quickly - only seven days from my order).

Great plastic container (instead of the more usual cardboard box), but surprised that no end caps included, so will have to keep in a plastic bag before putting back into the container.

Will test it (hopefully) tonight, but as someone already said - for this money even if it doesn't work very well in my f/5 Skywatcher it will be (I am sure) fine for my f/7.3 TAL.

[John]

I'll be interested to see what you think of it.

The Seben, Skywatcher and a number of other zooms seem to come in the same plastic container which makes me wonder if they all come from the same factory ?

[bambuko]

The container is not "bolt type receptacle" as described by OP (Big_Daz) ie  it does not un-screw.

You have to rotate it to correct position and than pull off rather than un-screw to open.

I am rather peeved off by the lack of protective end caps - it's the first thing I do when I am finished with eyepiece: put the caps on ... but I suppose I will get used to it.

More to come once I had a chance to use it (I am waiting for the lights to go off)

So far had a quick look at Venus and it was fine - the only thing that again I didn't like was, that every time you change zoom, you have to re-focus again.

I don't know if it is specific to this eyepiece or more general trait of zoom pieces (it's my first zoom piece)?

I have tried it in my finderscope and annoyingly retaining screw on the finderscope focuser happens to coincide with the point where eyepiece barrel dia changes from 1.25" to undercut, so had to secure it sticking out a bit to miss this point.

[John]

The container is not "bolt type receptacle" as described by OP (Big_Daz) ie  it does not un-screw.

You have to rotate it to correct position and than pull off rather than un-screw to open.

I am rather peeved off by the lack of protective end caps - it's the first thing I do when I am finished with eyepiece: put the caps on ... but I suppose I will get used to it.

More to come once I had a chance to use it (I am waiting for the lights to go off)

So far had a quick look at Venus and it was fine - the only thing that again I didn't like was, that every time you change zoom, you have to re-focus again.

I don't know if it is specific to this eyepiece or more general trait of zoom pieces (it's my first zoom piece)?

I have tried it in my finderscope and annoyingly retaining screw on the finderscope focuser happens to coincide with the point where eyepiece barrel dia changes from 1.25" to undercut, so had to secure it sticking out a bit to miss this point.

The zooms I've used are not 100% par-focal - you do need to refocus slightly or sometimes a bit more, as you move to a different focal length.

The containers I've seen with zooms of this type are cream plastic with a black end cap which has a sort of bayonet fit.

[bambuko]

The container is "milky" clear plastic:

and I suppose "bayonet" is a good description.

Thank you for clarifying non-parfocal bit.

[John]

Now thats what I would call a "bolt tube". I was thinking of this (see below) that many zooms seem to come in. Not that the shape of the plastic container matters that much !:

[bambuko]

Yes, but proper bolt tube has the groves threaded at an angle so that you can screw/un-screw the top.

These are parallel so that when you try unscrew the top nothing happens - you have to align it and then push/pull.

[Pig]

The Celestron Zooms come in the same container as your picture John

[Big_Daz]

Hi Bambuko, yes I also was a bit miffed about the lack of end caps but if placed into the little plastic bag first then in the plastic container (still bolt type just not screw bolt type ) then I'm hoping it will be fine. Waiting patiently for your opinions on build, quality and view ect. I did mention the need for refocusing whilst zooming, it would have been nice if it had been par-focal but for £20 I'm not going to grumble.

[bambuko]

I was all set and ready, waiting for the street lights to go off... and then the blumming clouds rolled in

I don't know why I am still waiting   but it it might get better

btw - thanks for confirmation that your piece also came without caps

[Big_Daz]

Hoping the sky clears for you bud and you're welcome. Looking forward to your opinion.