Posts Made By: Rod Kaufman

I'll cut to the chase: this is a splendid eyepiece! I tried it this evening in my 16" f4.5 dob as twilight fell and the clouds drifted away. Seeing was a 3/5. During periods of relatively steady seeing, and without a paracorr, coma was present at perhaps 75% outward or so but seemingly more suppressed than the 16mm version. Eye relief seems less than the advertised 22mm but it's more than enough. The eyepiece is immersive in the views it provides and it has the look, feel and performance similar to a high end unit.
While the views are decent enough without a paracorr, adding one significantly improves the edge performance so coma is not an issue. There is more lateral color at the extreme edge than the 16mm, and it appears as a bluish tinge to a bright star but is otherwise not a problem unless you care to look for it at the field stop.
I looked at Mars but other than being able to see it was Mars, there really wasn't much detail to discern, given its tiny, receding disc.
Obviously, this eyepiece is meant for widefield views of clusters and extended objects and I doubt it will disappoint observers in this regard. It doesn't have an 82 degree field but it is quite respectable in what it delivers, especially at its current price point.
If you've got a fast scope and a paracorr and you're looking for a longer focal length eyepiece that won't break the bank, jump on it.
BTW, I found this CN report on the same model, also tested on a fast scope:
http://www.cloudynights.com/item.php?item_id=1270

I've got the 18mm UO ortho as well as the 12.5 and the 6mm. Here are the specs from a websource:
http://www.tomhole.com/UO%20Orthos.htm
I think 12mm seems about right for the ER. It's probably doable with thin glasses but I don't wear glasses so I can't say for sure...

victor truglio said:

Are the older TV plossls better then the current line available.

I'd seriously doubt it, Televue wouldn't risk its reputation by coming out with an inferior product.

Tonight's gunfight:
Sight: LAAS
Target: Jupiter
Load and Brand: Circle Js, Baaders, Naglers and ranch hand TMBs
When the smoke clears, you pilgrims can read about it in the "Morning Appeal"

Looks like a bit of a price war has broken out:
First rapid fire salvo: New ES 82s coming in at around $99. Plus the 14mm 100 ES at $299. Not a bad deal.
Return fire: Celestron 15mm axiom 82 at 119. Ditto for the 22 and 32mm ultima 70s. And the 32 and 40mm omnis at $32 shipped. And an 8mm ultima 70 at $95 shipped.
So when is Meade going to enter the fight?

As usual, I'll have be the one to do it.
As usual, the first criteria is: does it meet FLOYD BLUE SPECS? For the uninitiated, the latter consist of: 1. Beyond multi-coatings(ie is it phase-coated for max reduction of chromatic aberrations?) Answer: Nope, it's got the usual purplish poop. 2. Is each lens surface ion milled for absolute zero surface scatter at temperatures at absolute zero? Answer: Er, ah, we're not talking Zeiss optics with this one... 3. Does it maintain a flat field at f4.5 with zero pincushion? (Don't even think about astigmatism with Floyd Blue specs, any hint of it and it's returned as defective to its maker, period.)(Paracorr or equivalent allowable only at f3.5). Answer, with four lens elements in the reviewed eyepiece, good luck! 4. Does contrast, resolution and definition exceed the theoretical limits of performance at 50X per inch of aperture? Answer: Not on your airy disc! 5. Eyepieces designated as "star party" types...need not apply. Answer: It's a perfect star party eyepiece!
So it flunks Floyd Blue specs.
So, what is it?
It's a multiple element, variable focal length (8-24mm), 40-60 degree AFOV, 1.25" ocular, better known as a ZOOM eyepiece, manufactured by (and rumored to be the same as the Celestron model) Zhummel zoom zoom eyepiece.
So how does it really perform at f4.5 in a 16" dob? Inquiring minds like Jon Isaacs want to know. First, however, he'll (along with the rest of you) will have to read about the packaging it came in, it's container, fit and finish, etc, just like you'll do if you read those reviews on that other cumulonimbus site.
Assuming I'll have clear skies on Saturday and I get my dob back together again, I'll put the pup through its paces and report back to you...stay tuned.

I can't believe this, last night clouds come out of nowhere as the sun sets. Today, the winds come up and it's clear all day but now a cloud bank covers the sky. I mean what do I have to do to get this thing done? I've got my newly recoated primary and secondary ready to go with essentially no dust on them to reduce scatter and the eyepieces are clean/new and there's absolutely no cooperation from above.
I was going to test the 8-24 zoom eyepiece, MILLIMETER by MILLIMETER in my 16" f4.5 dob (because, in part, inquiring minds like Jon Isaacs want to know) and the weather just isn't doing what the clock indicates it ought to be doing. I'm in the ten mile radius of Templin Highway on the clock and it doesn't look bad but the sky/wind conditions suck!
Maybe this high cloud cover will blow out before the night is gone but geez...

I managed to get a break, both in the clouds and in the seeing, and I was able to view Jupiter through the 8-24mm zoom eyepiece with my 16" f4.5 dob.
First, let me state that I will not be sending this eyepiece back for a refund as I had done with the 9mm 100 degree Zhumell model that I had previously reported on in past thread. Overall, I'm delighted with the zoom eyepiece.
I didn't detect any appreciable aberrations in the model except for a bit of lateral color on Jupiter at the edge of the field of view. I saw just a bit of an orange coloring at the limb of Jupiter at the edge but it was slight and nothing to be concerned about.
I compared the zoom at the 18mm and 12mm settings to my UO orthos of comparable focal lengths and didn't detect any significant differences in detail on Jupiter. I let Jupiter drift to the edge of the field of view in the zoom at various settings and didn't see much of a degradation in the cloud belts at the extreme edge of the eyepiece.
The unit zooms easily enough and maintains focus fairly well throughout its range but I did have to refocus a bit as I chased the seeing in the early evening.
I looked at M42 but I was close to a street light and a neighbor's flood light interfered with the view but it was fun to enlarge the nebula and see a bit more contrast to it as I cranked up the power.
I don't believe the eyepiece added any coma or astigmatism to the image and it was pretty sharp right up to the edge of the field of view.
The eyecup is very comfortable to use and it does a good job of blocking out ambient light. The eye relief is good but I don't wear glasses and if you do, you'll just have to try one out for yourself.
I paid about $49 for it new, including shipping. I think that's less than what I've seen the Celestron model go for used in the AM classifieds and they're reportedly the same models.
I've used a zoom in the past and didn't like it. The Zhumell model has changed my opinion of zoom eyepieces at this time. I certainly want to take it out under darker skies and play with it on DSOs. Additionally, I've acquired a new C90 spotting scope and I think the zoom eyepiece will make a great combination with it.

I doubt if anyone has cloned the Pentax oculars although the asrotech paradigm eyepieces bear a physical resemblance to the xl series. The astrotech paradigm series seems to have a similar design and number of elements as well but it's supposed to be an entirely new line of eyepieces.

Specifically, the T412mm model although I'd like to read comments regarding the lineup as well.
I've read quite a bit about the 12mm T4 model and it appears you either like it or you don't with very little in between. I can buy a one new from a vendor for about the same(low)price that someone is selling it for used but I've read comments on it regarding kidney beaning, lack of contrast and overall sharpness being less than its stablemates. Anybody care to share their experiences with the T4s?