My new wide-view Orion Stratus eyepieces are here! - Page 2

davidpretorius · #21 06-12-2005, 06:20 PM

great and very informative review!!

one of the best!

dhumpie · #22 06-12-2005, 06:37 PM

Excellent report Steve! You answered all my questions and more

Anyway the KK Widescan III 20mm came in last Wed and I had a chance to try it out under Ron's (Astro Ron) dark skies. The ep would not focus in my C6 (not enough focus travel) so I had to test it out in Andrew's (astro_south's) 12.5" f/6 dob. Very good across the entire field with maybe the last 1/4 of the field going soft. Eye relieve is okay although I need to move my eyeball around to take in the whole field so I guess it is less than 15mm er. Last night I had it tested in my Orion 80ST. Essentially the same performance as in Andrew's scope. Have not had a chance to test for flaring yet though.....anyway...

Darren

janoskiss (Steve H) · #23 06-12-2005, 08:40 PM

Quote:

Originally Posted by Starkler

Quite simple.
Get your collimation spot on and then check how tightly stars focus on a night of good seeing.

Do you mean the Airy disk is smaller in a sharper EP?

Stu · #24 06-12-2005, 10:10 PM

Sharpness can also be a bit more detail. When Dave and I were comparing the panoptics to the meade series 5000 plossls the stars were just as sharp (at F8 mind you) but something to do with the background was different. In a really dense star field, using the plossls I couldn't really see much background but in the pano's i could amost see faint star clouds or something like that. It's hard to describe, but the liked the view more.

Argonavis (William) · #25 06-12-2005, 10:22 PM

Quote:

Originally Posted by janoskiss

I might do that Mike..
Anyone know how to compare sharpness between different EPs?

Steve - great report. I would encourage others to do the same, as they are invaluable guides before people spend often big $ on eyepeices.

Interestingly, Baader have recently began marketing their Hyperion line of eyepeices, which appear almost identical to the Stratus (same 68deg FOV, 20mm eye relief, same focal lengths), with the addition of threads for DSLR's and claimed superior coatings.

janoskiss (Steve H) · #26 06-12-2005, 10:24 PM

Stu, that sounds like contrast rather than sharpness...

janoskiss (Steve H) · #27 06-12-2005, 11:12 PM

Quote:

Originally Posted by Argonavis

Steve - great report. I would encourage others to do the same, as they are invaluable guides before people spend often big $ on eyepeices.

Interestingly, Baader have recently began marketing their Hyperion line of eyepeices, which appear almost identical to the Stratus (same 68deg FOV, 20mm eye relief, same focal lengths), with the addition of threads for DSLR's and claimed superior coatings.

I saw the Hyperions last week at York Optical in Melbourne. They were going for $265 each (or $285 maybe). At that price though there are more options, such as the Meade SWAs and UWAs. On superficial inspection the coatings look the same on the Stratus and Hyperion. In fact, the eyepieces look almost identical except for the longer 2" barrel bit on the Hyperion. This should help the EPs reach focus in a 2" focuser without needing a 1.25" adapter. Only the 21mm of the Stratus line can be used as a 2" EP in my Dob. On the other hand, Baader warns that the 1.25" barrel of the Hyperions might hit the mirror in a 2" diagonal. No problems with the Stratus there, which work fine with my ED80 + 2" mirror diag.

Starkler (Geoff) · #28 06-12-2005, 11:58 PM

No Steve, a sharp eyepiece will focus stars to a pinpoint of light (given good seeing and a good scope), whereas with a less sharp one they will appear as blobs.

Definition of sharp : My pentax xl in Marks Tak

ausastronomer (John Bambury) · #29 08-12-2005, 02:13 PM

Steve,

One of the best tests for sharpness of a high power eyepiece is to count the craterlets in Plato (on the moon) and compare which craterlets you can and can't see in the respective eyepieces and how easy they are to see. Unfortunately this doesn't help with the longer focal length eyepieces you are dealing with here.

One option is as Geoff mentioned to focus on a star and see how tight they focus down but there are a few things to be aware of here.

When you are working with lunar/planetary features, to compare eyepiece sharpness, the analysis generally takes long enough to even out the effects of variable seeing as you will get enough moments of "good seeing" with each eyepiece to enable you to judge the eyepieces performance when the air was still. It's unlikely that you will get this same evening out effect on a single star or starfield, as their simply isn't enough to concentrate on with "a few stars". You need to be able to evaluate what is attributable to "seeing" and what is or isn't attributable to the eyepieces themselves and sometimes you need more than "a little" experience to figure this out. As Geoff mentions if your going to do this using a starfield make sure its a night of good stable seeing to eliminate as much as possible atmospheric variations. I also recommend that you try to use stars of approximately Mag 7 to Mag 10 (if you use this method) as stars in this range will not be as affected by diffraction effects eminating from the scope itself (eg. spider, secondary, mirror clips etc).

Another option is to pick the eyepiece "you think" is going to be the least sharpest of the bunch. Study the moon and select a lunar feature that is on the verge of visibilty and resolution and then see how it looks with the other eyepieces and see how much better the other eyepieces resolve the same features. Then work in the reverse order on a different set of features starting with the eyepiece you think will be the sharpest.

CS-John B

janoskiss (Steve H) · #30 08-12-2005, 03:02 PM

Thanks for the tips John. I can't wait to give the EPs another workout. Only if the clouds buggered off...

davidpretorius · #31 08-12-2005, 04:22 PM

thanks john, food for thought.

asimov has sent my his LV 5mm, so i hope to compare the 6.5mm series 500 and the LV 5mm and then 12.5 in the 2.4x barlow with the moon tonight!

Looking at the vixen, it is lovely, but i can't help feeling that is a cheat ie a 10mm eyepiece with a 2x barlow. Is this quite common to simply add a barlow to the design?

but then again,

janoskiss (Steve H) · #32 08-12-2005, 04:33 PM

That's how most of the ultra-wide designs work, Davo, including the Nagler.

janoskiss (Steve H) · #33 10-12-2005, 03:19 AM

After one last long look tonight (dodging clouds), I have decided to keep my 19mm Panoptic and sell the 21mm Stratus. This decision came after a number hours spent looking through both eyepieces. The Stratus definitely wins in the ease-of-use category. You can look into it from practically any angle and see the full field. The

Panoptic wins in the aberration category [ aberration(panoptic)=0.5 x aberration(stratus); small = 0.5 x small ]

janoskiss (Steve H) · #34 19-12-2005, 08:34 PM

Spanner in the works: a fantastic 2" barlow!! Wow! Don't need the 8mm & 5mm Stratus anymore. Keeping the 13mm. I will write up the whole saga soon.

Argonavis (William) · #35 19-12-2005, 10:09 PM

Quote:

Originally Posted by janoskiss

Spanner in the works: a fantastic 2" barlow!! Wow! Don't need the 8mm & 5mm Stratus anymore. Keeping the 13mm. I will write up the whole saga soon.

What barlow? where did you get it?

Argonavis (William) · #36 19-12-2005, 10:11 PM

actually I love my barlows - I have televues x2, x1.8 and x2.5 and a klee x2.8, no powermates, I assume that the older TV barlows are every bit as good as the newer powermates, but I have never tested this proposition

janoskiss (Steve H) · #37 19-12-2005, 10:23 PM

Quote:

Originally Posted by Argonavis

What barlow? where did you get it?

2" Japanese barlow, leftover from BATSC (now merged with Bintel). Supposed to be same as the University Optics barlow. It is baffled extremely well and with the 19mm Panoptic it creates a near perfect 8-8.5mm eyepiece. It works very well with my HD orthos with little loss of contrast. Way better than the generally highly regarded Shorty Plus which I sold cheap after I got the 2" barlow.

mick pinner · #38 20-12-2005, 07:11 PM

l tried the Stratos 8mm in the Meade last night and l can tell you it does not work at f/10, terrible beaning regardless of eye placement, however it works a treat in the Zenithstar at f/6.

janoskiss (Steve H) · #39 20-12-2005, 07:55 PM

Sorry to hear, Mick. What were you viewing? With the Moon you need a filter. Neutral density + blue works best for me. Otherwise in my Dob, f6 or barlowed f6 (effective f12-13) the Stratus have been very well behaved and very forgiving when it comes to eye placement.

mick pinner · #40 20-12-2005, 09:00 PM

l was looking mainly at dso's with the sct at bothf/10 and f/6.3 and it did not work for me, however when in the Zenithstar it works a treat, nice wide crisp views, different ep's for different scopes that's all. l must say that the finish and quality of the ep seems first rate.