Help me choose

[R26 oldtimer]

Hi there,

I was about to pull the trigger on a nice Hyperion modular 8mm with both fine tuning rings, to cover the 5ish focal length as well (6-5-4.3mm). Although the reviews are quite good, I'm not so sure that the optical quality with the fine tuning rings will be good.

On the other hand, for the same price could acquire something like the 5 and 8 BST Starguiders or similar (any suggestions)

So how does the Hyperion modular 8mm compares to the 8mm BST Starguider?

How does the 8mm Hyperion finetuned to 5mm compares to the 5mm BST Starguider?

Is the view from the 8mm Hyperion with both fine tuning acceptable, good, or bad?

Is the view from the 8mm Hyperion without the nosepiece(barlow)  at 21.8mm acceptable, good, or bad, or completely distorted as opposed to my 26mm meade super plossl?

My scope is a slow 5", F/10 refractor, eyepieces intended for lunar and planetary high-power yielding at 150x(8mm) & 240x(5mm)

Your thoughts please...

 

P.S. : The Hyperion finetuned to 6mm covers the gap between 150x-240x with a nice 200x, that's another thing to consider

[RobertI]

Hi,

I have a 10mm Hyperion with finetuning rings and a 5mm BST star guider. I haven't done a back to back test, but I have found the quality using the Hyperion with the fine tuning rings is very good, no noticeable degradation. Removing the nosepiece gives a 2" eyepiece, but I recall that the view towards the edge of the field becomes distorted, so not so successful, but still usable if you have nothing else of that FL. I would prefer the Hyperion over the BST as the 68 degrees is a noticeable improvement over the 60 degrees in my opinion, but if you are planning on swapping FLs frequently during a session then i would go for the two BSTs as screwing and unscrewing FTRs can be a pain in the cold and dark.

Rob

[alan potts]

Personally I have had one hyperion in a faster scope than that and found it awful. I also would not mess with this fine tune system, it is far too easy to drop bits and also get dust into the works. I feel you could do better buying something like am 8.8mm or 6.7mm Ex Sc 82 degree,in my opinion a better eyepiece. Having said that BST's are highly regarded on this site by many, though I have never tried one.

Alan

[Ruud]

Hyperions are strange eyepieces. Why have finetuning rings when you really need an optimal spacing of the lens groups?

From the reported performance of the Hyperions the nozzle is not a Barlow. It is more likely that its negative group is a Smyth lens: a part of the design needed to correct aberrations of the positive part. A Smyth lens too works best when spaced correctly, and it can only work when it is present.

Maybe you should check out the Celestron X-cel LX. No gimmicks and good value. No fumbling in the dark. X-cel LX, like Hyperion, is best suited for f/7 or slower. From the reposts, the X-cel LX is as good as the Hyperion at its best. Here's the 5mm on the website of Flo: https://www.firstlightoptics.com/celestron-eyepieces/celestron-x-cel-lx-eyepiece.html

[RobertI]

Good advice from Alan and Ruud. I would hesitate to label the FTR's a gimmick though, unless someone can demonstrate they just don't work (my experience seems to say otherwise, but I'm not an expert). But I certainly wouldn't recommend Hyperion + FTRs over the mentioned alternatives.

[Louis D]

If they were still available, I'd recommend the Speers-Waler 5-8mm zoom.  It basically has a continuously variable separation between the negative and positive groups.  I have one and it works quite well at all focal lengths.  Barring finding one used, you would be better served with 3 eyepieces rather than trying to mess with one eyepiece and tuning rings in the dark.  The BSTs are available in 5mm and 8mm while the Meade HD-60 is available in 6.5mm to split the difference focal length wise.  I have the latter, and it is nearly perfect across the field in slower scopes.

[alan potts]

10 hours ago, Louis D said:

If they were still available, I'd recommend the Speers-Waler 5-8mm zoom.  It basically has a continuously variable separation between the negative and positive groups.  I have one and it works quite well at all focal lengths.  Barring finding one used, you would be better served with 3 eyepieces rather than trying to mess with one eyepiece and tuning rings in the dark.  The BSTs are available in 5mm and 8mm while the Meade HD-60 is available in 6.5mm to split the difference focal length wise.  I have the latter, and it is nearly perfect across the field in slower scopes.

These really were rather rare even when they were made, I believe this stopped about 5-6 years ago, maybe more. I actually got one secondhand here in Bulgaria which was nothing short of amazing. They were fairly expensive new which I guess is understandable, mine also had the extension sleeve making it go down to 3mm. By and large it was a very good eyepiece but I did feel the edges were a bit colourful, but that was putting it again my other TV eyepieces which is not really fair. I sold it on to a site member.

Alan 

[R26 oldtimer]

That's some great advice, keep them coming, I need more feedback, especially from hyperion users.

Reading between the lines so far seems that the Hyperion 8 outperforms a starguider at it's native focal length but not with the FTR's. The thing is that how much beter is the hyperion than the starguider at 8mm and how much worse is the hyperion+FTR's compared to the 5mm starguider?

Also I should point out that I am not concerned about fiddling with the FTR's as I observe from my backyard and not a dark site, although kidney bean and black outs bother me a lot (I have a celestron Xcel 10mm, non lx with terrible black outs).

To make things even more difficult how about instead of the starguiders the Hyperions stand against those cheap tmb planetary clones?(with great respect to Thomas Back)

Hyperioners, come aboard...

[R26 oldtimer]

Thank you all for your responses. I finally got myself a Hyperion zoom Mk3 and a 2x focal extender , sacrificing my TV Radian 3 . Hope I did well!?!