trade my 14mm UWA S4000 for your 22mm Panoptic ***PENDING***

bytor666 · #1 22-09-2005, 08:42 PM

Anybody want to trade their 22mm TeleVue Panoptic for my Meade 14mm UWA series 4000?..Mines in mint condition with plastic bolt case, drop me a line if this interests you !!!!...cheers !!!

I am also very willing to sell it for $250.00 Canadian with the shipping included, that's if it isn't too much to ship from here to Austrailia !! Can't wait to read that shootout on the 14mm UWA and the nagler 13 T6 !!!! and the 14mm Pentax XW!!!
If you are interested my email is bytor_666@hotmail.com thanks!!!!
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Mark
12" Gso Scope

***SALE PENDING***

Starkler (Geoff) · #2 22-09-2005, 09:33 PM

Bargain !

If I didnt already have a 14mm pentax id buy it.

bytor666 · #3 22-09-2005, 10:26 PM

I smell a trade here Geoff !!!...how does that 14mm Pentax work out in an f/5 telescope?...if it's good, I will trade it for my 14mm meade UWA !!!...whaddya say to that?
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Mark
12" Gso Scope

ausastronomer (John Bambury) · #4 22-09-2005, 10:34 PM

Somehow Mark I don't like your chances

CS-John B

bytor666 · #5 22-09-2005, 10:57 PM

Well John, after reading about some tests, the 14mm Pentax has some curvature near the edges, whereas the 14mm UWA is ultra flat right from edge to edge. The 14mm (Pentax) however rivalled the 14mm UWA on axis and throughput.
You are right ,the Pentax is more expensive though, I was going to trade mine and offer cash as well.
I am also waiting for a 10mm Pentax XW in the mail !!!!...somebody actually caved in and sold it used hehehehehe..I used to have a 7mm XW and now this 10mm XW will be putting a HUGE smile back on my face !!!!

I am now looking for a trade for my 14mm UWA with a 22mm Panoptic instead!!!
Cheers John , your tests and info have proved to be extremely useful to everyone, including myself.
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Mark
12" Gso Scope

Starkler (Geoff) · #6 22-09-2005, 11:37 PM

Hi Mark . Im happy with the eyepieces that I have, but im sure you wont have trouble selling your UWA

bytor666 · #7 23-09-2005, 01:50 AM

Geoff, there's a chap here in my hometown that has a Pentax 14mm. Can you tell me what it performs like in your 10 inch scope?, Is your 10" an f/5?...just curious to know how good the 14mm Pentax is because it has some negative field curvature.
Here is a page that shows it, looks like the 10mm and up shows positive field curvature and from when I looked through my 7mm Pentax XW , it was ultra-flat right to the extreme edge of the field stop without any lateral color at all.
I don't want to judge your 14mm XW on a chart alone, I just wondered how it performed in your telescope.
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Mark
12" Gso Scope

iceman (Mike) · #8 23-09-2005, 05:52 AM

I've used John's Pentax 14mm XW in my 10" f/5 scope, and there is some field curvature at the edge, but on axis it's very sharp and is a very nice eyepiece. Very comfortable to use.

ausastronomer (John Bambury) · #9 23-09-2005, 07:40 AM

Mark,

Mike hit the nail on the head, its all about compromises. Unfortunately eyepieces of different focal lengths in the same series are not always created equal due to physics; the 14mm and 20mm Pentax XW's are no exception. They are not quite as good IMO as the 5mm,7mm and 10mm Pentax XW's which have no field curvature whatsoever in an F5 scope and are oustanding eyepieces in almost every respect. In terms of the field curvature we are talking about a minor aberration when compared to two other premium eyepieces. You can notice it if you look for it and AB it with the Meade 14mm UWA or the 13mm Nagler but when using the eyepiece in isolation it doesn't really affect the view IMO. In terms of cheaper eyepieces the Pentax walks all over them. ie we are not talking about off axis slits like you get in cheaper eyepieces, the star images remain circular at the EOF but visualise tham as being 2% to 5% off perfect focus. Moving the focuser an absolute fraction brings the EOF into focus and takes the center out by the same amount. The field curvature IMO is an artifact of preserving the 20mm of eye-relief in all focal lengths of the series and this is the compromise. I cannot use the Meade or Nagler without my glasses on so my own eyes cause very slight off axis astigmatism in these eyepieces when I use them without glasses on, so we are almost back to square 1. My own eyes off axis astigmatism gets worse as the eyepiece focal length increases due to the increasing exit pupil size. I know however that this aberration is my own fault and not the eyepieces, but there are a lot of eyeglass wearers in the astronomical community and a lot of them suffer the same issues. Its not too bad for me with eyepieces in the 10mm to 20mm range but once the eyepiece focal length gets over 20mm and the exit pupil over 4mm things start looking pretty ugly

. In terms of on axis sharpness and light transmission the 14mm Pentax is a little better than the Meade and also the 13mm Nagler T6, but the Nagler has slightly better contrast IMO. I don't wish to give too much away at this stage as Mike, Louie and I still have more testing to do. We will probably do more this coming new moon and finish the testing next 1st quarter. Mike will then write up the review and post the results. Ultimately all 3 eyepieces are superb and considering the Meade is currently available for under $AUS300 on the used market compared to $AUS460 for the Nagler and $AUS480 for the Pentax, the Meade is clearly the best value and IMO possibly the best value for money eyepiece available on the used market at present, in conjunction with its little brother the Series 4000 8.8mm UWA.

Just as an aside, I regularly use the 14mm Pentax barlowed in the 2.5X TV Powermate for lunar/planetary/double star observation. It gives 220X in my 10"/F5 scope and the powermate eliminates any trace of the field curvature, consequently its a superb combination for medium/high power observation whilst retaining 20mm of eye-relief. I actually prefer it to a 6mm Radian.

Can I ask why you are selling the 14mm Meade UWA, because other than its physical size its a superb eyepiece IMO? Also what are those charts you have attached re the Pentax eyepieces, how can I get a larger readable version of them, curious to have a look?

CS-John B

Starkler (Geoff) · #10 23-09-2005, 08:18 AM

Mark mine is an XL , not an XW, but the performance is very much the same as how John and Mike describe it. For those wanting an XW, the XL could be a satisfactory alternative at a cheaper price on the 2nd hand market. The most obvious difference between the pentax's and the others is the comfortable 20mm of eye relief which I have come to appreciate.

My 14mm gets 75% of my scope time, either barlowed for planetary or on its own for dso's.

bytor666 · #11 24-09-2005, 03:13 AM

Excellent information John. I am selling my 14mm Meade Series 4000 UWA because I was reading that the transmiassion and contrast on axis with the 14mm Pentax XW was better, (plus the fact that I like to try all kinds of them out and I am crazy because I just want them ALL- LOL). I have looked through a 7mm Pentax XW before too , and those eyepieces are just simply AMAZING!!!!
I am glad that I found out from you that the field curvature was so minimal, and not like the seagulls we normally see in other designs. The curvature that you were talking about in the 14mm XW is so minimal it might as well not even be there !!!!
So, I have a sale Pending on my 14mm Meade series 4000 UWA, and a lad in my country here is selling me his 14mm Pentax XW for me to give a go!!!...I also didn't mention that I have the chance at a 20mm Nagler T2 over the Pentax !!!!

Next week also brings a 9mm Nagler type 6 to my door,( in MINT condition), when I was supposed to get a Pentax 10mm XW !!!!...The store made a mistake and sold the 10mm XW to somebody else!!!...this is why I am getting a 9mm Nag T6, the 10mm XW got sold, and also the reason for getting the 14mm Pentax XW (the 10mm XW was sold to someone else by mistake).
Can't wait for that report from you guys!!!!..thanks for all that eyepiece information, I will be testing them next week myself and give you guys the report on them both !!!

About that chart on the Pentax eyepieces, I found it on Cloudy Nights. (I hope they don't mind me putting it up here), you can find it somewhere in there on CN , but I forget where because I got it a loooooong time ago!!!
----------------------
Mark
12" Gso Scope
eyepiece junkie