Seben Zoom 8-24mm, Cheap Zoom Eyepiece

[baggywrinkle]

Some very good posts here from the OP downwards. I will now have another look at the Seben zoom or the Celestron one. Good to see such advice.

[jgbreezer]

Reviving this post to ask if anyone also has experience of Seben's 7.5-22.5mm zoom - seems different enough from the description (though quoted 8 could be rounded up from 7.5, 22.5 only rounds up to 23 not 24) that it ought to be a slightly different zoom (or more recent version)?? Anyone come across both and able to compare them?

[cotterless45]

I've only heard very positive reviews of the 8-24mm. I got hold of a 2nd hand SW and Meade 4000 zoom 8-24mm. Really superb in faster refractors, especially for showing double stars.

The faster Newts don't give such good results with plenty coma and troublesome focussing,

Nick.

[Dave In Vermont]

I found this on Amazon in the UK for dirt cheap - 20.59 pounds delivered:

http://www.amazon.co.uk/Seben-Telescope-Eyepiece-7-5-22-5mm-Astronomy/dp/B00EL5XU9S

But what caught my eye was that it has 12 reviews. You might wish to take a look. As for the 8 - 24mm zoom's, they are made in China and sold branded with many names. Mine is Vixen. Works fine for my purposes.

Clear Skies,

Dave

[Stu]

I bought of those for my children to mess around with. It does a job but is not great to be honest, it suffers from internal reflections quite badly as there is no blackening of lens edges etc

[StarcrazyGeoff]

Whilst on the subject of the Seben Zoom Lens, Seben also do a laser guided collimation adaptor for setting the mirrors on a Newtonian scope. It is priced just over £24 and is available on Amazon (Free Postage). It has had some very good reviews, apart from the odd one, who thinks it is no good, but you always get reviews like that, no matter how good the product is.

Worth having a look for yourself though. Apparently, there are also some videos on Youtube, showing you how to use it.

[Moonshane]

I have the 8-24mm seben for solar / school use and got it used for £30. For my use and that sort of cash it is great value. I use it for solar in f10 and f5 fracs and it is impressive. No real difference to my tv plossls for narrowband observing.

[Raya K]

Are Celestron 8 t 24mm zoom as good as, worse, or better than Seben's?

[Moonshane]

I think it it the same

[John]

Raya K has started another thread on the zoom question so, to avoid confusion, shall we continue the discussion there ?

http://stargazerslounge.com/topic/247558-celestron-8-24mm-zoom-vs-seben-8-24mm-zoom/

[andre2]

Hi, do you recommanded to buy a sky watcher 8-24 mm ( hope that iTS not made in China) or for a bit more the celestron zoom ( made in. China?) for my coronado pst alpha H scope? ( if the sky watcher is not made in china, maby iTS better then both the seben and celestron(?!) )

[John]

28 minutes ago, andre2 said:

Hi, do you recommanded to buy a sky watcher 8-24 mm ( hope that iTS not made in China) or for a bit more the celestron zoom ( made in. China?) for my coronado pst alpha H scope? ( if the sky watcher is not made in china, maby iTS better then both the seben and celestron(?!) )

The Skywatcher 8-24, Seben 8-24 and Celestron 8-24 and a number of other brands are the same, chinese made, zoom so take your pick !

Nothing wrong with chinese made stuff as far as I'm concerned - they do some great optics these days

[Dave In Vermont]

Chinese eyepieces, and the majority of other astro-gear, are the norm. But Chinese optics got bad reviews (deservedly so) some years backs. As a result, their poor reputation for performance lingers on. But the two biggest Chinese outfits - Synta & GSO - have really stepped-up to improve their gear and, by proxy, their reputation.

The two Chinese manufacturers I am speaking of are Synta ib the People's Republic of China, and GSO - Guan Sheng Optics - in the Republic of China (Taiwan). In my experience of recent time, they are both very under-priced! So I have no fear on "pulling-the trigger" and buying their gear - eyepieces & zoom's & a million other goodies.

The Seben 8 - 24mm Zoom notably included. And as John pointed out, most Zoom EP's on-the-market are coming from the same places and made of the same materials - the brand-names stops mattering for the most part regards optical performance. There are some notable exceptions, such as when looking at the Vixen LV 8 - 24mm Zoom. The Vixens cost around $200 in the USA, but look identical to many other brands which retail anywhere from $70 and up. But why is this Vixen offering selling at more than 2X the others? It's because Vixens' have a lens made with their legendary Lanthanum-enhanced glass. As a result, they do show a marked increase in the detail and coma-free FOV (Field-Of-View) across the view. I have a Vixen LV Zoom, and it was well worth it imho.

 

Seben 8 - 24mm Zoom EP.

 

Vixen LV 8 - 24mm Zoom EP.

 

I also have warning - all the legit complaints I've heard about zooms' have been about the 7 - 21mm(or 22ish) zooms. These have a different optical-design from the 8 - 24mm. And are often best avoided. There are, of course, exceptions.

Hope this helps -

Dave

 

[davyludo]

Just curious.....

Do these budget 8-24mm zooms work well with faster scopes (F5 refractors)? Or are they best suited to longer focal length maks and newts?

Cheers,

Davy

[Relpet]

I bought the Seben 8-24 a couple of years ago.  It does a reasonable job.  If you remove the rubber ring you'll find a thread beneath which you can screw into the T-mount of a DSLR.  You won't get fantastic pictures but for showing somone the basic principles you'll get a reasonable picture of the moon through all the zoom range.  What I don't like about Seben's marketing is that they offer a gift if you give them a rave review on ebay or Amazon, so don't necessarily trust those reviews.  I did post a three-star review once explaining why it wasn't higher but something else I bought from them was too good to mark down and I ended up with a packet of sweets.  The attached picture was taken three days ago by eyepiece projection through an 80mm apo refractor, (just for information not for critical response).  If, as other posters say, the same product is available under different brand names you might prefer to go that route.

[Dave In Vermont]

1 hour ago, davyludo said:

Just curious.....

Do these budget 8-24mm zooms work well with faster scopes (F5 refractors)? Or are they best suited to longer focal length maks and newts?

Cheers,

Davy

I've used my Vixen LV 8 - 24mm zoom in all my scopes, from my 80mm F5 ST80 and up to my F10 12" Meade LX-series. It works fine in all. They're about as picky as a garden-variety Plössl. Remember - the Vixen differs from the Seben by the lanthanum lens-element, other than this minor addition, they are optically the same beast.

Dave

[John]

7 minutes ago, Dave In Vermont said:

. Remember - the Vixen differs from the Seben by the lanthanum lens-element, other than this minor addition, they are optically the same beast....

 

Are they ?. Same glass types (other than the lanthanum element), same coatings, same lens figuring, same internal baffling ?. I just wonder how you know this

[davyludo]

2 minutes ago, Dave In Vermont said:

I've used my Vixen LV 8 - 24mm zoom in all my scopes, from my 80mm F5 ST80 and up to my F10 12" Meade LX-series. It works fine in all. They're about as picky as a garden-variety Plössl. Remember - the Vixen differs from the Seben by the lanthanum lens-element, other than this minor addition, they are optically the same beast.

Dave

Thanks for the info Dave. Its just that after reading that f5 scopes can be a bit more fussy about eyepieces, I wasn't sure if a cheaper zoom would be suitable (under £100).

I'll look into zooms a bit more. At the moment I have a 25mm and then nothing until 9mm - a zoom might help me decide what fixed value I want in the middle.

Just feel it would be convenient for quick sessions, or taking away camping.

Cheers,

Davy

[Dave In Vermont]

1 minute ago, John said:

Are they ?. Same glass types (other than the lanthanum element), same coatings, same lens figuring, same internal baffling ?. I just wonder how you know this

I would hope the same way you know 'stuff.' If I get interested in a subject, I track down all the info I can get my paws on and Study! Study! Study!

I was very fortunate. By the time I was 12 years old, I grew an absolute hate for the public-schools in my hometown. So in the 2nd. month of the 7th grade, I walked out the door. My dad was an MIT professor. He handled my defection stoicly, and handed me an MIT Affiliates Card and account (good for life). Despite the screams of my mother, I trundled-off to MIT & Harvard and lived out of the research libraries and developed my 'Study! Study! Study!' philoophy and methodology. In so doing, I learned something I hadn't known about until much later.....

What I loathed the most about the public-schools was they made me subconsciously link education and learning with pain and torment. I wanted to learn, but if I remained in the towns' school-system I'd wind up hating it and also believing one should avoid 'education' like one avoids sticking their fingers in a switched-on electric-fan! The linkage was unmistakable. I also understood why so many of the others of my generation were essentially 'Forest Gump' stupid.

So this, in a nut-shell, should give you an overview on why I learned about zoom-ep's - my desire to learn trumps my aversion to learning.

Have you learned anything from this, John?

And they may have variations of certain things like lens-coating and such - as specified by the retailer, such as Seben. But it comes as no mere coincidence that they look like the same thing.

 

Davy - they are very convenient! Easy to pop into a pocket for a 'grab & go' excursion. As well as for community-outreach adventures. People think these things are great! So much so - they may actually take up astronomy themselves. Try that with a case of different eyepieces.

Enjoy!

Dave

[John]

So they look similar ?

Thats it is it ?

 

[Dave In Vermont]

Do you remember the fiasco of Vixen vs. TeleVue® back in the 90's (I think)? A great deal of information came out as a result of it. I've told the tale here before, and was rather surprised to find it hardly got any play over here in the UK. So I'll be brief:

People noticed an uncanny resemblance between the Vixen LV 8 - 24mm zoom and the TeleVue® 8 - 24mm zoom -

 

 

 

It was then suggested thet TeleVue® was getting their  8 - 24 made in the same place as was Vixen. Now TeleVue® was claiming at this time to make everything themselves in the USA (this was the 90's). And this caused a jolt through the astro-community and press. TeleVue® denied it was the same zoom. The upshot of this was people took them apart and found they were identical. Still TeleVue® hung on denying it. But with all the evidence and parts stacked against them - they finally admitted it true - but made it clear that they, TeleVue®, always examined each & every lot being made wherever, and cherry-picked the best ones from each. It was ludcrous. People got bored and didn't care.

TeleVue® removed their 8 - 24 from the market. The Vixen lives on.

But from this, the practice of 'branding' was being exposed to a quite broad audience. And many eyepieces were opened-up and played with. And now it's widely known over here that the eyepieces in one's eyepiece-case(s) come from only a couple places - notably through Synta and GSO. The brand-names on them have less meaning now compared to just a few years ago. Who actually does the real work, I didn't bother to remember. But I know who could give you all those fine details. He's a real "Eyepiece-Nut" whom I converse with daily. Very nice and smart guy! If you have a specific question about a specific eyepiece, you could write it up and send me a PM. I'd be happy to pass it on. The schematics of these particular 8 - 24's, perhaps?

Anywho - off to check the sky again. One more band of t-storms and it's supposed to clear up.

Fingers' Crossed,

Dave

 

[Stu]

7 hours ago, davyludo said:

Thanks for the info Dave. Its just that after reading that f5 scopes can be a bit more fussy about eyepieces, I wasn't sure if a cheaper zoom would be suitable (under £100).

From what I've read the Seben will be fine at f10 in say SCTs or longer fl fracs and is useful for solar Ha but likely to show some edge abberations at f5.

[Dave In Vermont]

From what I see using my F5 ST80, my Vixen and Hyperion 8 - 24mm Zooms work just fine.

I'll take using over reading anyday! It also works quite well in my 200mm GSO F4 Newtonian.

Seems these zoom's are good in just about any scope. And I bought that Vixen LV back in 2002, and have a fleet of telescopes I've used it in - from F4 to F12. I'm not in the market for more telescopes or zoom EP's. I'm quite happy where I am now with my gear-collection.

Dave

[Mr Spock]

7 hours ago, Dave In Vermont said:

I would hope the same way you know 'stuff.' If I get interested in a subject, I track down all the info I can get my paws on and Study! Study! Study!

Can you produce your sources? I'd be interested in reading up on this too.

[chiltonstar]

I use a Seben 8-24 in my Maks occasionally, and I have to say it's ok - great for setting up, and for little folk, who have the habit of leaving conjunctivitis behind on EPs. I don't feel too worried about cleaning the optics of a cheap zoom with an antiseptic lens wipe which I might not want to do with something more costly.....

John - you seem to be the in-house EP expert...... Does the spec for a lens get passed to a lot of different factories, so products emerge with a superficial similarity, but very different performance? I wonder too whether quality failures appear on the market with a different brand name? (I prefer the word "similar" to "identical").

Chris