Do the Hyperion show any weakness down to f6

[-Aldebaran-]

Looking to upgrade soon from stock Ep's and was pondering over the Hyperion. Using in 200p Dob, heard somewhere that they don't perform so well at f6? Any info would be great.

[John]

They perform very well in the central 80% of the field of view at F/6 but I found I was seeing astigmatic stars (ie: "seagull" shapes) creeping into the outer 20% approx of the field when used with my F/6.5 refractor. At F/7.5 that is much reduced with more like 95% of the field being sharp.

Everybody has a different tolerance level for this sort of thing though so other eyes might see it differently.

[ronin]

I know Hyperions have a lot of support but isn't that pretty bad for an eyepiece in an f/6.5 scope?

Lets face it they are a £96 eyepiece.

Another new person from Wrexham I see, is it the f/5 or f/6? I guess the f/6.

Think there are about 6 SGL people (at least) from Wrexham.

[AlexB67]

Given the ability in keeping  a sharp field across the field and their price  I would not even consider them quite frankly based on all the reviews I've read in scopes below f/7. I'll say that with the proviso I've never looked through one. What sort of focal length are you looking for ? At 68 degrees the Maxvisions are a steal at almost half the price depending which focal length you are after. 

I use two of them the MVs 28 and 20mm, while by no means perfect at f4.7 ( they are rated for f/5) they are very good to my eyes, some field curvature can be noted and very minor astigmatism at f4.7, anything else that deteriorates the image  is coma induced by the scope.  In your 8 inch they should preform very well I would imagine. 

[-Aldebaran-]

I have been looking into the Es maxvisions recently, mid power say 16mm, can pick up for as little as £50, are these good performers at f6? Dob F.Length is 1200, the reason I was looking into the Hyperion was that I can use it on the 2" focuser as I read somewhere that FOV is better on 2" rather than 1.25"?

[John]

The Hyperions are 1.25" eyepieces which have a 2" lower body that can be used straight in a 2" drawtube. They remain 1.25" eyepieces though with a 68 degree apparent field of view. If you remove the 1.25" barrel and the lens assembly that is in it you get an approximately 22mm 2" barreled eyepiece but it's not a very well corrected one.

The Hyperions are not bad eyepieces by any means but sharp edge of field correction in faster scopes is not their forte.

[-Aldebaran-]

Thanks for the Intel, I'm a complete newbie to this hobby, and just like my other hobbies in mountaineering I know it can get expensive, especially concerning EP's. The DSO fuzzies I've been spotting lately with my stock 25mm have made me look into better quality SWF EPs so any info on the right kind of F.Length EPs to bring a sharper image would be appreciated, cost wise - no higher than say, £100?

[luminova11]

I have also have a 200p dob and I use the MaxVision 68° EPs. I currently have the 40mm and the 16mm. I think that they are fantastic and cannot personally fault them at all. Much more experienced astronomers than I mention them in the same breath as Televue and Pentax so if that is not recommendation enough I don't know what is, and at a fraction of the price. With a decent quality 3x barlow the 16mm also makes a very good planetry eyepiece on the 200p dob.

Sent from my LG-D802 using Tapatalk

[-Aldebaran-]

O.k here is where I'm at after some extensive window shopping and using the £100 mark as a good but not exclusive budget....choices being.......

Slightly above budget:-

Explore Scientific 82° 8.8mm/14mm

Celestron luminous 82° 7mm/15mm

Meade 5000 Uwa 82° 8.8mm/14mm

And below budget:-

Skywatcher SWA 70° BEASTS!! 8mm/17mm

Explore Scientific MV 68° 16mm

I am not ruling out the Badder Hyperion but I do like the sound of the aspheric 31mm for DSO viewing.

If anyone has experience in any or all of the abovementioned for a good push in the right direction I would appreciate it. Oh and just to point out I have a Rev Astro 2.5 barlow and was wondering would this impede on true performance of said Ep's? I suppose viewing is only as good as the weakest component.

[russ.will]

I tried out a Hyperion in my (then) F5 SW 200p and felt it offered nothing I wasn't already getting with my BST Starguiders, or rather Explorers as they were then, at near half the cost. The extra FOV advantage was debatable because it was a mess of astigmatism.

Having then gone for the Explore Scientific ES82 EPs and now having the Maxvision SWAs as well (indeed, some replaced certain ES82s), I can confidently state that the MVs are a far better corrected EP down to the F4.9 of my old SW 300p and current ES 305 dobs than the Hyperions. With the slight reduction in AFOV with the MVs, I don't find myself bothered about a coma corrector either like I was with the longer ES82s. The 'BUT' in all of this, is that the MVs are a little tight on eye relief compared to the Hyperions, but unless you wear glasses, it's not exactly a problem.

If you don't wear glasses and given the price differentials, the MV are a no brainer for someone in the sub-£100 upgrade game. For about £120, you can land the 24mm and 16mm MVs and with a decent barlow (I also have the Rev 2,5x), that's a lot of quality views for not a lot of money.

With your F6 dob, the MV 34mm is a nice finder EP, although I find that it and the mighty ES82 30mm that went before it (and it was lovely) get used less than you might think. As soon as I find something with it, I'm increasing the magnification to frame the subject better and tease out more contrast - As such, the 24mm (because it's also 1.25" = less faffing with adaptors) is perhaps the most used of my longer FL EPs. It's also less of a Dob balance issue, which is another problem with the seductive, but hand grenade weight 2"ers.

Russell

[russ.will]

I should have added; that at higher powers (11mm FL or less) the extra FOV of the ES82s does save on the nudging and because coma is less apparent with shorter FL EPs, the subject stays observable for a longer time.

I'd still look at the MVs (in the FLs they're available at) first, as they are reputed to be a short term offer. This 'term' does seem to have dragged a bit, but the 20mm doesn't seem to be available any more, so maybe there is some truth in that rumour...

Russell

[AlexB67]

I should have added; that at higher powers (11mm FL or less) the extra FOV of the ES82s does save on the nudging and because coma is less apparent with shorter FL EPs, the subject stays observable for a longer time.

I'd still look at the MVs (in the FLs they're available at) first, as they are reputed to be a short term offer. This 'term' does seem to have dragged a bit, but the 20mm doesn't seem to be available any more, so maybe there is some truth in that rumour...

Russell

When I ordered the 28mm from Germany and asked about this I was told stocks were getting low, whatever "low" means, but customer services  were honest with me and said if I ordered in 2 months time or so ( this was back in December I would probably be okay, but he could not guarantee it based on sales. 

As it happens the 28mm still shows as in stock now on the same site where I ordered it,  as is the 20mm.

http://www.optical-systems.co.uk/en/Maxvision-68-Okular-28mm.html

http://www.optical-systems.co.uk/en/Maxvision-68-Okular-20mm.html?listtype=search&searchparam=maxvision

As It happens I swear one time ago this one, as was perhaps another MV.

http://www.optical-systems.co.uk/en/Maxvision-82-Okular-24mm.html?listtype=search&searchparam=maxvision

was showing as low stock, yellow icon , but now it is green again.

Are they cloning them somewhere ? Not sure what's going on with that "one off" deal  

[russ.will]

I will bow to somebody with a more stable internet connection than mine. At the moment, I'm on a campsite with a wireless connection that seems picky about which one of the six(!) ES websites that now abound. ES.co.uk won't work whilst telescopes.fr (and obviously here) do, but I can't see the 20mm on any site that I can currently get to work.

Either way, I've got all of them, so I'm alright Jack!

Russell

[-Aldebaran-]

Yes they do seem limited, thanks for info.

Ant.

[NickK]

Hmm I use a 3.5mm,13mm and 32mm asp hyperion with a f6.38 pezval doublet (that's the pentax 105mm).

I've not noted any issue - perhaps it's because the field is flattened before it gets to the eyepiece.

[-Aldebaran-]

I bit the bullet, and after careful consideration I made my first eyepiece upgrade purchase today.

I finally settled on the 14mm Explore Scientific 82° should be through the door and on the scope by the end of the week! Very excited. My next upgrade may very well be the higher power 8.8mm 82° if all goes well in the 14mm. All I need is to find a decent enough dark site now as my semi rural location may hinder DSO finds. Does anyone know a SGL topic that discusses good dark site area's??? Thanks all again for ur input

Ant.