The "value" of Eyepiece Review(er)s

[Macavity]

If this is TOO controversial, please feel free to delete the thread.

I guess I'm feeling a bit "miffed" with a recent eyepiece purchase - Based largely on a NUMBER of ecstatic "reviews", and also VENDOR blurb. Put simply, when is "sharp to the edge" [of field] really SO? Sure, "They SAID it was" - But, to MY (modest practical experience) it is manifestly NOT! To my mind, it's sharp over, at best, 40% field. Yet worse, a phrase "blind man on galloping horse" comes to mind. Sadly, I seem to have paid 3x the cost of a previous eyepiece, for no better performance.

I'm dumb, but you needed a laugh? [wry grin] But hopefully more productively: Have folks any general tips on assessing eyepieces (OR eyepiece review(er)s!) Have we not progressed to some more... "scientific" way of evaluating eyepiece performance? Or perhaps the only answer is to school oneself? (I feel I am making hard-earned progress towards this latter?) "Caveat emptor", I guess? But I still feel SADDENED. I know I'm not an experienced observer, but WHY do folk "big up" stuff like that? I guess genuine ignorance, rather than any real malevolance, but...

That said, can I encourage SGL's (potential!) reviewers - There seems to be FAR more "substance" to opinion here. If not, it gets tactfully and kindly, "corrected"? Perhaps that is what is needed - More "warts and all" pieces from those of limited budget? I mean, I KNOW Mr. Nagler's product is going is SO much better than my stuff - Already! I'd certainly value opinion from those of... modest means. At this rate, my funds are rapidly going to be ever MORE modest!

[GordonCopestake]

I think it very much depends on the 'scope that you use the eyepiece in. For example even the cheapest plossl gives half decent performance in my f/10 SCT (as do my naglers), but the same plossl in an f/4 astrograph is unlikely to be appealing to the eye (the naglers hold their own of course, even at f/4). As to your original question though, as with all things that are seen through your own eyes it's very much personal preference as to what works for you. At the end of the day, only you can decide what works for you. Personally I find only 3 range of eyepieces that "work" for me in 3 different budgets. 1: Cheap and cheerful GSO plossls, independent of brand. 2: Baader Hyperions, great wide'ish angle and decent even at lower f/ratios 3: Naglers, for all those fast 'scopes. Your lineup may be different.

[GazOC]

When reading reviews on astro gear I'm always wary of 'The Emperors New Clothes' syndrome (eyepieces and apos seem to suffer in this regard) , someone has just sunk a few hundred quid into new gear, can't find any immediate faults but then totally goes over the top when reviewing it based on only a couple of nights observing. Its only human nature and I'm sure I've been as guilty of it in the past as anyone. I try a find as many separate reviews/ opinions on an item before I come to decision on whether to purchase...then I use it once and write a review.

Specifically with eyepieces people should take note of what type of scope the reviewer(s) were using when testing the eyepiece, the fact an eyepiece is 'sharp to the edge' in a f10 SCT doesn't mean much if you intend using it in a f5 Newt. EDIT: I see Gordon has beat me to it!!

[GazOC]

If this is TOO controversial, please feel free to delete the thread.

lets live dangerously....

BTW Mac, which eyepieces were you referring to?

[Black Shuck]

BTW Mac, which eyepieces were you referring to?

Yes please Chris, would be interested.

Cheers

Bill£

[Jamie]

Bet its the one i most cherish in my collection....

[GazOC]

Bet its the one i most cherish in my collection....

Thats what I was thinking...

[Macavity]

Heheh. Well, lest I keep you all "in suspenders"

I refer to my recent purchase of a 31mm Baader Hyperion Aspheric. In truth I have yet to look through anything "better" (Pan 35 etc.) but somehow, this one doesn't match up to my (eager) expectation. Nor indeed some of the rave reviews. I may INDEED be wrong. And that, taking account my experience, naff observing site etc. But I read with interest (and some chagrin!) the albeit "Germanic" translation:

http://translate.google.com/translate?hl=en&sl=de&u=http://forum.astronomie.de/phpapps/ubbthreads/ubbthreads.php/ubb/showflat/Number/401676/page/1&sa=X&oi=translate&resnum=9&ct=result&prev=/search%3Fq%3Dbaader%2Bhyperion%2Baspheric%26hl%3Den%26client%3Dopera%26rls%3Den%26hs%3D27a%26sa%3DG

Yay, the "Worlds longest link" appears to work.

It may be that my feeings have some substance? I have e.g. never am able to see this eyepiece as better (admittedly at F5!) than my "canonical Moonfish". They are admittedly looking at the 36mm, whereas I am looking at the 31mm. Indeed, Gordon, (re. scope F-number) I sense the 31mm Asph. may be OK in my MAK127 at ~ F12. It ain't so good at F5. But maybe the world (me) is not quite ready for the "Aspheric". That said, I may be very wrong in this assessment...

On a positive note, "everyone" seems to like the "Ordinary Hyperions" (Eh, Gaz?). So, I guess much of my "collection" will be deemed generally OK. <G> As you say, guys, the psychology of reviews can be interesting. And, in that, I too am responsible. So, as every, my opinion, with a grain of salt... But Food for thought, thoughbut?

[Jamie]

Phewww!!!

[GazOC]

I do like my Hyperions even at f4.5 (which is just as well as I can't afford anything more expensive!), they show coma towards the edge but to get of that would start to cost serious money.

re. the Moonfish/ Aspheric...if the Aspheric is poor at f5 then it doesn't really have any advantage over the cheaper Moonfish as that eyepiece becomes pretty good itself at f10. Using either on a 127mm Mak has limited use as the hole in the back of the scope governs the maximun FOV the scope can provide.

I love that translation BTW....

[Jamie]

I love that translation BTW....

Classic...

[Macavity]

Using either on a 127mm Mak has limited use as the hole in the back of the scope governs the maximun FOV the scope can provide.

Ah but, with one of these (A working Baader product):

http://www.telescope-service.com/baader/accessories/accessories.html#prisms

Specifically the 35mm T2 to 2" adaptor-diagonal. You can accomodate many a 30-something 2" eyepiece with a MAK127. My Moonfish has (estimated) 74 deg AFoV, so is slightly vignetted. The Hyperion Asph. 72 deg is clear. A step in the right direction maybe, SHOULD one want maximum possible TFoV with a MAK127. Perhaps, one day, a S/H Pan 35... Equity release, second mortgage...

Yup, nowt like a good "translation" to brighten an afternoon!

[GazOC]

(A working Baader product):

Ouch!!

[jakey]

I will now add my 2 pennys worth of eyepiece reviewers. If you want a independant review stay clear of Cloudy Nights. I find that if the eyepiece is American it is always excellent. If the eyepiece is not American, then it is not worth buying.

Look at the comparisons between naglers and pentax XW, praise a pentax you get slapped down. praise a nagler and the flags start flying. A wellknown reviewer stated that the pentax was only good for birding.

I own both types of eyepieces and I can say the the pentax is better,in design and in build quality.

Might also mention that many naglers are actually built inthe far east.

Rant over, delete if you must.

[Macavity]

Hey, Gaz. Actually, Baader products are indeed "the best". IMO, anyway.

And, lest I should add to the "general confusion" with knee-jerk "review"?

"Opinions are...", as they say. Thanks folks, anyway.

[GazOC]

And lest I should add to the general confusion with knee-jerk "review"?

Feel free, I always qualify my knee jerk reviews by mentioning that I've hardly used the product....

[Kenny_10_Bellys]

For me the limiting factor is the Mk-I eyeball, specifically mine. I'm colourblind, and since i took up astronomy and work in front of PCs all day my vision has been getting increasingly more bizarre. It could be the best eyepiece in the world and what I see through it will differ considerably from someone else. I'm quite happy to buy a relatively cheap eyepiece as I'm not breaking the bank, but I would never lash out more than £50 on an eyepiece I hadn't tried out myself at a star-party or similar.

[James]

I have several quality eyepieces including two Panoptics a Nagler and a Pentax 10XW. On my limited experience I'd have to say I agree with jakey on the Pentax.

Naturally if asked, I'll tell you the eyepieces I have are blumming marvellous (and they are in my f/4.7 scope) in part because they represent a sizable investment (even second hand). However, this is subjective and no one who's splashed out a small fortune for an Nagler is going to tell you its rubbish.

Eyepieces are very personal, what one person likes another will hate. For example I hate any evidence of astigmatism in an eyepiece and therefore don't like eyepieces that show this in my (or any other scope). Plenty of others will look through the same eyepiece and scope and will characterize it as just a little distorted towards the edge but no big deal...I had a chance to look through a 26mm Meade Plossl at Kelling in April (thanks Daz) which showed astigmatism in the last 30% of the field in my scope which to me wasn't good but in fact in the centre of the field the view was better than my 24mm Pan. Someone who wasn't bothered by/aware of the astigmatism would wonder why I'd spent so much on the Pan. The view was much better in the Lightbridge that Daz took to KH but it was f/5... If I had a higher focal ration scope I'd consider getting that eyepiece.

Pentax appear to be willing to post details of their eyepieces such as field curvature and transmission which showup which of their eyepieces are liable to problems at certain focal lengths which appear to gel with users experiences but even then a little field curvature for some will be unnoticable to others.

I guess at the end of the day the only way to really check is to try before you buy. Easier said than done of course but the next star party I get to I'll be asking people for a quick look if they've got an eyepiece I've been considering.

James

[Macavity]

Interesting. Glad my thread is productive, rather than merely "inflamatory". Clearly much is subjective and (in some sense) you "pays yer money" for performance? In that way, it would perhaps be wrong of me to "negate" my Aspheric Hyperion. I may yet have to "understand it" better?! In some sense e.g. the edge performance "recovers", rather than decreasing monotonically out - Perhaps intentionally so? It might be "not so bad" on (my favourite) open clusters etc. - for "Framing" etc.

As a "continuation" of the Hyperion series, perhaps it "ain't so bad" either - Given increased focal length in a faster scope etc. I might even speculate it's in some "linear progression", with it's Hyperion bret'rin, performance-wise. But, as a newbie-ish astronomer, I guess I was surprised (initially) that eyepieces were indeed NOT "perfect". (Too many years with my old "brass spyglass", Jim-lad!)

These days I have more sympathy with e.p. developers. From personal experience, I sense one can waste quite a bit of time and money, trying to find a "better" mid-cost 30-something mm e.p. for faster scopes. Maybe it ain't gonna happen! Anyway, if my house move comes off (equity relase etc.) then I too may be lauding Naglers *AND* Pentaxes - I may even manage to afford a BIG old Dobsonian...

[lunator]

Maccers

I think you mean coma as the distortion?

I use orthoscopics and they can show coma on the outer 10% of the field in my F6 newt but for £20 a eyepiece across the other 90% the views are as good as any other eyepiece I observed through.

[James]

Maccers

I think you mean coma as the distortion?

I use orthoscopics and they can show coma on the outer 10% of the field in my F6 newt but for £20 a eyepiece across the other 90% the views are as good as any other eyepiece I observed through.

I've always figured that coma should be what I'm seeing given my scope and its focal ratio but the distortion flips 90 degrees when I go each side of focus which I've always thought was astigmatism. (?) For all my sensitivity to astigmatism I appear not very sensitive to coma...

[GazOC]

Mac,

I think in a fast (<f5) Newt you are going to have to accept some coma in a wide angle 30mm+ eyepiece or think about getting a paracor and eyepiece combination that'll probably end up the wrong side of 500 quid.

[Macavity]

Aaaaargh. There I am at fault - We're talking "cheap 'n' chearful" Startravel ST102 F5 achromat. Who knows what inherent aberrations lie within it? It must be a stern test for ANY eyepiece! Regarding aberrations generally, I was given a LINK to a site that perfectly described "astigmatism" (trying to find it!) Quite a lot of terms are banded about (by me too!) are with little knowledge. I sense it is useful to understand the VISUAL appearence of such things. I do think I now have a handle on "astigmatism" - Looks like the Moonfish & ST102 delivers quite a LOT of that. Hope we're not beating a "dead horse" here, but sometimes one (me) can learn a thing or two from others in the process...

Ah, here it is: http://stargazerslounge.com/index.php?topic=11154.0 (therein!)

[GazOC]

For some reason I have started banging on about Newts when you are using a refractor....sorry!

I use a 80 deg Moonfish in my 150 f5 refractor and its far from great but its a lot better than in my f4.5 Dob, I've also bought a 70 deg Revelation S/H to see if thats any better although I suspect it will just be the same as the 80 with 10 deg blacked out....

Astigmatism....

[Macavity]

If all else fails (off-topic) Eisley is "distinctly luvverly" and very (sic) talented!

(not seen ever before, either...)