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View Full Version here: : Eyepeices between Hyperion/Stratus and Nagler/Pentax XW


PeteMo
02-03-2007, 02:35 PM
I'm looking at getting an eyepiece in the 19mm - 24mm range and am presently considering the Hyperion/Stratus 21mm. I cannot afford over $400 for the likes of the Pentax XW 20mm, Panoptic 22mm etc, but can probably go to about $350-ish. Are there any wide angled eyepieces (65 - 70 degrees) that fall between the two ranges in terms of price and quality?

My scope is an 8" F6 Dob with a 1 1/4" R&P focuser.

astronut
02-03-2007, 03:07 PM
Hi Pete,
I can eagerly recommend the Siebert Line of optics.
They're made in the U.S. by Harry Siebert a latter day Al Nagler.
He makes different levels of optics, with the Ultra being the top of the range.
The e/p's are plain to look at, but their optical quality is very close to the Nagler line and at a much reduced cost. One main advantage is they're made from aircraft aluminium, so they are much lighter than the standard e/p's.
They are made in 1 1/4" + 2" sizes. Del to OZ takes about 10 days.
The Ultra's in particular are made to work on fast scopes (F5 and below) as well as the slower scopes. Go to the site for a look www.siebertoptics.com (http://www.siebertoptics.com) :D

janoskiss
02-03-2007, 03:31 PM
22mm LVW is one of the best widefields you can get near the 20mm mark. Better than Panoptics IMO, and well worth the extra over the Stratus & Hyperion, and has virtually none of the field curvature issues of the 20mm XW. Other option worth considering is the 21mm Denkmeier (try talking to Frontier Optics) - based on John Bambury's comments this is probably even better than the LVW.

The only Siebrt Ultra I've used is the 3-element 24mm and it was very ordinary at any f-ratio and also fell well short of spec ito FOV. It could be the black sheep of the line, but those EPs are not exactly cheap...

iceman
02-03-2007, 03:43 PM
I would agree that (in my experience) the 22 LVW is better than the 22 Pan. However the 24 Pan is better than both of those.

I also remember John commenting that the 20mm Pentax XW suffers from some field curvature, even worse than the 14mm Pentax XW.

PeteMo
02-03-2007, 03:46 PM
Hi John thanks for the Siebert recommendation - I'll check it out.

Hi Steve
Thanks for the info on the LVW 22mm. I see that MyAstroShop (where I got my Hyperion) sell the Vixen Range. I'll also see what the Denkmeier has to offer.

Thanks for all the advice. I'm blown away with my Hyperion so can only guess what these other eyepieces must be like.
Cheers
Pete

PeteMo
02-03-2007, 03:48 PM
Hi Mike
Thanks for the extra info. I did look at the 24mm panoptic, but at $429 it is not far off Pentax XW territory price wise. The Vixen LVW seems to be the basis for the Hyperion/Stratus range of lenses.
Cheers
Pete

Starkler
02-03-2007, 09:09 PM
Yes at that price and focal length I would be looking at the Denkmeier and the Vixen LVW.

Fox
03-03-2007, 01:47 PM
PeteMo, I heartily agree with the above, 22mm LVW all the way, particularly given your price criteria, you would not be disappointed. I have the 13mm LVW and its one beautiful EP. Not only top optical performance, but the finish and quality of construction are very attractive! Fox.

ausastronomer
07-03-2007, 09:38 PM
Pete,

I am replying "on forum" in case anyone else is interested in my comments re the 21mm Denkmeier.

The 1st thing I would be doing is spending about $100 and putting the 2" 10:1 GSO crayford focuser on that scope. The supplied 1.25" focuser is pretty average and IMO good eyepieces are wasted in it. The GSO 2 speed caryford is a pretty good unit, although I did go through 3 of them before I got one that didn't have "issues", when I fitted one to my 10" scope. Bintel exchanged the first two without any problems.

Around this focal length I own the 20mm Pentax XW and the 17mm Nagler T4. I have also used the 19mm TV Panoptic, 20mm Nagler T5, 21mm Denkmeier, 22mm TV Panoptic, 22mm Vixen LVW, 22mm Nagler T4 and the 24mm TV Panoptic.

Of all of those I would rate the 20mm Nagler T5 as optically the best overall with its 82 degree AFOV and sharp views to the EOF. However it has a very high price tag, short eye relief and 2" only barrel, which may restrict you if you only have 1.25" filters. Of the others, I prefer the 21mm Denkmeier and by a reasonable margin. I have used it in scopes as fast as F4.5 and it provides lovely sharp views right to the EOF, has excellent throughput and contrast, excellent eye-relief and comes in a very small light 1.25" package. Landed in Aus it may cost you a tad over $400 but it is worth every cent IMO. If you don't need the extra AFOV of the 20mm Nagler T5 (and I don't) the 21mm Denk is every bit as good as the 20mm Nagler, better in many ways. The 22mm Vixen LVW would be my next pick and it comes in a bit behind the Denk IMO. It is also a lot bigger and heavier. In some scopes and for some observers, the 20mm Pentax XW is better than all of them. As others have mentioned it does suffer from field curvature in some scopes, dependant on design and focal length and this is also a lot more noticeable by some observers than others, due to different peoples own eyes ability to adjust focus at the EOF. The 14mm Pentax XW also suffers from minor field curvature, but not quite as bad as the 20mm Pentax XW. In the 18"/F4.5 Obsession the field curvature of both eyepieces is minimal. Several fellow IIS members observed with the 14mm Pentax XW at Kulnurra and IISAC at Lostock and not one person from several dozen made any comment about the field curvature, which was barely noticeable. I see it because I know it's there, but you really have to look for it. When combined with a paracorr in the 18" Obsession the field curvature of both eyepieces is effectively eliminated.

In conclusion, the 21mm Denkmeier is worth every cent and I would be going that way in a heartbeat, it is "almost" perfect in every sense and is bulletproof. Using it singly and not in a binoviewer is not an issue in any way. I have only ever used it singly.

CS-John B

PS: Scott Mitchell (Wavelandscott) purchased two pairs recently 14mm and 21mm (the 14mm Denk is just as good as the 21mm) on my recommendation and I am pretty sure he is very happy with them both.

rockit
07-03-2007, 11:23 PM
Hi PeteMo, I hear what your saying My12"light(white)bridge came with a 26mm QX, heaps of curvature in the outer portion. I reversed the bottom element this almost removed almost all curvature and increased it to 24mm aprox. Still has a wide view you can look around inside it to see all the field. I like it, with my $29 GSO 26mm kelner(called fully multi coated plossl) they pair of well. One gives a big field and the other flat feild.
Hope this helps. You dont need to spend tons on ep's.
Save it for more scopes and better mounts.

rockit
08-03-2007, 12:12 AM
I just noticed 1.25 rack and pinion. With the money I saved you on eyepieces, grab a 2" GSO crayford from Andrews they are $99 for the 10-1 or $89 STD.:eyepop:

PeteMo
09-03-2007, 11:56 AM
Thanks guys for your input.
I've decided to go for the Denkmeier in a few weeks time. Also I made enquiries with Denkmeier about ordering direct from them, and have included the email response from Russ Lederman for the benefit of other members:

The eyepiece can be sent to Au. We have some casual dealers in AU but
the eyepieces have really very little margin of profit and if that is
all that you want, you can order from us here direct. In fact, you can
use the website and I manually charge the card anyway so under comments,
you can state "one D21 only" and I will charge the card $249 + $30 S/H
Global USPS to AU. The D21 will include the aluminum vault.
Clear skies,
Russ Lederman
Denkmeier Optical

John I'll let you know how I get on when I get it.
Cheers
Pete

ausastronomer
09-03-2007, 12:10 PM
Pete,

I am sure you will like it. It is a very high quality product in every respect, in keeping with the quality of the Denk Binoviewers.

You may or may not like the "winged" eye guard that it is supplied with. I don't like it, my US friend that owns the Denk eyepieces I use, likes it. The good thing is, you can just peel it off in a matter of seconds, if you don't like using it.

CS-John B

janoskiss
09-03-2007, 12:42 PM
Pete, I'd encourage you to buy from a local dealer if at all possible. I know of Frontier Optics - www.frontieroptics.com.au - don't know if there are any others. i'd make contact to talk prices... but at the prices you have been quoted I don't think there is any savings to be had by ordering from the US anyway.

Blaznee
09-03-2007, 02:58 PM
I am currently in the good ole US of A and have been doing a lot of research comparing the price diff between here and home.

Matthew at http://www.telescopes-astronomy.com.au/ and Daniel at http://www.frontieroptics.com.au/ offer prices that are on par with what's available over here.

Janoskiss is spot on when recommending buying local because most manufactures warranties are invalid outside the country of purchase

wavelandscott
09-03-2007, 05:07 PM
In the end I only bought a pair of the 21 mm for a new Binoviewer (Denk Big Easy)...I've only used them in "bino" mode but I can confirm that they are very nice...good finish and build. The winged rubber guard is a bit funky but it is growing on me.

John is right, I am happy with them so far.

I suspect at some future point I will pick up the 14 mm too.