Tom Trusock
Reged: 02/26/02
Posts: 27405
Loc: Alternate Reality (TM)
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Type 1's, Type 2's and the Zooms
article
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There are two theories to arguing with my wife. Neither one works.
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galaxyman
Pooh-Bah
Reged: 04/04/05
Posts: 1171
Loc: Limerick, Pa
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Very nice article Tom.
Oh, I do own one of those 11mm Type 1 Naglers 
Karl
E.O.H.
Chesmont Astronomical Society
Telekit (Swayze optics) 22" F/4.5 Dob
Homemade (Parks Optics) 12.5" F/4.8 Dob
TMB 8" F/9 Refractor(The Beast)
Antares 6" F/6.5 Refractor(Mini-Beast)
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So many galaxies, so little time!
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Ron B[ee]
Tyro
Reged: 04/27/03
Posts: 4719
Loc: CA
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That's a great article, Tom  . Already looking forward to Part 2  .
Ron B[ee]
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5-inch Tele Vue NP127 APO 
4-inch Tele Vue TV-102 APO 
8-inch f/6 Discovery PDHQ Dob 
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timmbottoni
Pooh-Bah
Reged: 08/25/05
Posts: 1112
Loc: W Chicago suburbs, IL USA
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Thanks Tom!
Great article as always!
Timm
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WO Megrez 80FD, Celestron C8
WO SWAN 33mm, UWANs 4mm, 7mm, 16mm, WO SPLs 3mm, 6mm, 12.5mm, WO Zoom II 7.5-22.5
WO EZTouch & Celestron Nexstar GT modified mounts
SV F50B2 Finder in WO Quick Release 50mm bracket
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Tom Trusock
Reged: 02/26/02
Posts: 27405
Loc: Alternate Reality (TM)
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For those of you keeping track, yes this thread (and the accompanying article) did magically vanish for a day.
Suffice it to say I goofed, and posted the article before I'd done my final rewrite.
It's better now.
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There are two theories to arguing with my wife. Neither one works.
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JohanK
super member
Reged: 05/21/07
Posts: 163
Loc: Ghent, Belgium
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Phew. I thought something was wrong with the cache of my browser. Can't wait till the type 4's are passing the revue.
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Johan
Orion XT10
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Starman1
Vendor - Scope City
Reged: 06/24/03
Posts: 10960
Loc: Los Angeles
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Tom,
I've recently done an extensive comparison of the 17mm T4 and the 16mm T5. It'll be interesting to hear your comments when you get there.
Don
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Don Pensack
12.5" Truss Dob, 5" Maksutov
Sustaining Lifetime IDA member, TeleVue junkie
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Mr. Bill
Carpal Tunnel
Reged: 02/09/05
Posts: 2759
Loc: Just passing through.....
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Boy, those bring back memories....I still have the flat top 13 mm which required fastidious head placement. That was an ep best used sitting down.
Also have the 9mm flat top; still a great ep.
Oh yeah, digging through my "collector's" case, there's a 4.8mm; never really liked it much because of the short er, but as you said, not bad for a high power ep.
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10x50 Fujinon FMT-SX binos
15x70 AP binos + Paragon p-mount
Oberwerk 100BT 45 degree + Hercules fork mount
120mm f/5 Orion achromat + Moonlite focuser
140mm f/5.7 Vixen NeoAchro Petzvel refractor
150mm f/6.5 Antares achromat
150mm f/8 homemade achromat....EE Barnard MW Sweeper
8 inch newt with f/5 Swayze mirror
10 inch f/4.7 Orion newt + Paracorr
15 inch f/5 Discovery split tube
35mm Pan, 26mm Nagler, 17mm Nagler, 13mm Ethos, 8mm Ethos
Member IDA
Edited by Mr. Bill (10/31/07 03:46 PM)
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Starman1
Vendor - Scope City
Reged: 06/24/03
Posts: 10960
Loc: Los Angeles
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Just a note that isn't addressed in Tom's discussion, but one that bears mentioning, is that there is a small, but real, variation from eyepiece to eyepiece.
TeleVue has reduced that variation to an ultra-low level, but, having twice had the chance to compare three of the identical model/focal length from TeleVueand finding *slight* differences between them, I would say that the variation in eyepieces is close to the minute differences that some observers note between eyepieces of identical type but different brand names (like Orion Stratus vs. Baader Hyperions for example). It's extremely subtle, but real.
That makes sense because of the huge stack of optical sub-components stacked together to make an ultrawidefield eyepiece.
Despite that, the high level of quality found in any TeleVue eyepiece is such that I don't feel compelled to purchase 3 eyepieces every time I buy one just in order to cherry-pick the best one. I'm sure that I'd be hard-pressed to notice a difference 99.99% of the time.
But in the two TV eyepieces I did compare this way, I did see a difference between eyepieces--on axis as well as off-axis. I liken it to the differences between 1/6th wave at the wavefront and 1/10th wave. One is better and under some specific circumstances may perform better, but you'd be unlikely to notice a difference under most conditions.
In addition to the vast differences between scopes in which the eyepieces are evaluated, this factor could be a contributor to the review results we see posted.
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Don Pensack
12.5" Truss Dob, 5" Maksutov
Sustaining Lifetime IDA member, TeleVue junkie
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Tom Trusock
Reged: 02/26/02
Posts: 27405
Loc: Alternate Reality (TM)
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Yup. Good points Don. I'd go so far to say that's part of any commercially produced product (at least that's available to typical mortals), and further TV does a good job of keeping that standard deviation as low as or lower than any other company out there.
Further, TV has improved their coating processes over the years, so it's concevible that one may even see a very slight difference between eyepieces that while otherwise identical differ in date of manufacture.
I have a friend who used to buy three TV eyepeieces, compare them, keep what he felt was the best and sell the rest for a loss.
Frankly, all of his observing buddies (me included) would been happy with any of them (Heck, most observers are happy with NEAF blems - which are basically Tele Vue rejects). The differences (when they existed and we were able to spot them) were vanishingly small.
But while I agree with you in most respects, I still suspect that the scope types, experience and individual biology play a greater roll in the diversity of reviews we see however.
T
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There are two theories to arguing with my wife. Neither one works.
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Tom Trusock
Reged: 02/26/02
Posts: 27405
Loc: Alternate Reality (TM)
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Thanks for the comments folks!
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There are two theories to arguing with my wife. Neither one works.
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Starman1
Vendor - Scope City
Reged: 06/24/03
Posts: 10960
Loc: Los Angeles
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Quote:
But while I agree with you in most respects, I still suspect that the scope types, experience and individual biology play a greater roll in the diversity of reviews we see however.
T
Agreed.
Don
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Don Pensack
12.5" Truss Dob, 5" Maksutov
Sustaining Lifetime IDA member, TeleVue junkie
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doctordub
scholastic sledgehammer
Reged: 01/11/06
Posts: 908
Loc: New Rochelle, New York
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Thanks Tom, excellent article as allways! I do notice a slight improvement in contrast of the T6's over the T1's, but I am keeping the T1's my first premium eps. The Nagler zooms are my favorate planetary eps and I could kick myself for not buying them sooner! For DSO the T4's are my favorates, but I have not looked through an Ethos yet!
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Jonathan
TeleVue TV102 on Vixen SXW mount
Meade LXD 55 SN10/UHTC Modified
Jason 60mm F11
Canon 15x50 IS
Olympus E-510, 14-42, 40-150 Zuiko
Meade DSI, LPI
TeleVue:
Binovue & 2X Cor.
3x barlow, 2x 5mm, 2x7mm,
12mm, 17mm & 2-4mm Zoom Naglers,
2x24mm, & 27mm panoptics,
55mm Plossl & 3mm Radian
2" OIII & Nebustar filters
Siebert Power Mag wheel
Lumicon Filter selecter &
2" focal reducer
Celestron: 7 1.25" color filters
7.5mm, 26mm eps & 2X ultima barlow
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Peter Argenziano
Watcher of the Skies
Reged: 11/11/03
Posts: 2813
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Tom,
That's a great article... can't wait for the other three parts!
I donated my 11mm T1 to the local observatory where it gets lots of use each clear night.
By the way, a segway is a two-wheeled, self-balancing electric transportation device invented by Dean Kamen and unveiled in December 2001.
A segue is a method of smoothly transitioning from one topic to another.
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Peter
14.5" Starmaster
I hail from the explosive jetsam of a multitude of high-mass stars that died more than 5 billion years ago.
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MikeRatcliff
Pooh-Bah
Reged: 06/12/04
Posts: 1107
Loc: Redlands, CA
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I owned a 9mm and 13mm T1 and a 20mm T2 for a while as the main lineup. They were nice but the 20mm was too heavy for my modest Crayford focuser, the 13mm's kidney beaning would drive me crazy if I were looking around the edges while searching for an object, and the 9mm just wasn't as sharp in the center as it could be, esp compared to a 9mm CircleT ortho.
So now the line up is a little more modern: 22mm Panoptic, 14mm Meade 4000 UWA, and 10.5 Pentax XL. ACHHH! The 22mm was just discontinued, so now I'm back to a legacy lineup.
I will say that out of all of the these eyepieces, if I had to choose one, the keeper is the 10.5mm Pentax XL. Sorry, TV.
Mike Ratcliff
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16" f/4.9 dob
Tele Vue Plossls 32,25,20,15,11
13 Nagler T6
10.5 Pentax XL
Brandon 32, 16
12.5 UO ortho, 9 Circle T ortho
2x TV Barlow
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Moggi1964
Carpal Tunnel
Reged: 11/07/05
Posts: 2512
Loc: Madison. NJ. USA
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Quote:
Tom,
That's a great article... can't wait for the other three parts!
I donated my 11mm T1 to the local observatory where it gets lots of use each clear night.
By the way, a segway is a two-wheeled, self-balancing electric transportation device invented by Dean Kamen and unveiled in December 2001.
A segue is a method of smoothly transitioning from one topic to another.
Now THAT'S why you deserve Star Contributor
I never knew that (about the segway machine not the spelling of segue).
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Morris
WO Megrez 80 ED F/7
WO 8x42 binoculars
Seymor Rosin F/4.5 Astrograph in the making
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Tom Trusock
Reged: 02/26/02
Posts: 27405
Loc: Alternate Reality (TM)
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Ah, the wonders of spell check. Thanks Peter.
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There are two theories to arguing with my wife. Neither one works.
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Daniel Mounsey
Vendor - Woodland Hils
Reged: 06/12/02
Posts: 2881
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Hi Tom,
I've been away from the forums, just taking a break for a while and then I stumbled on your review while taking a peek on CN. This review is important and is something the industry needs to hear but for me it's mostly about the fact that certain aberrations are simply inherent in parts of the optical train and sadly the eyepiece is blamed in cases where it shouldn't be. I'll never forget how John Pons described an F-4 Newtonian mirror to me. He said a perfect F-4 is like a perfect set of oval wheels. No matter how well the ovals are made, the car will still ride up and down.
The moral of the story is that no matter how well an F-4 is figured, it's still an F-4 with lots of inherent coma and the list goes on for every other optics issue out there. Good work Tom!
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Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14687
Loc: Hurricane Alley
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Awesome article Tom.
I can't wait to read the next installment.
So, where does my particular 7t1 fit in? It does not have the dual barrel, but it does have a grip ring and rubber eye guard? So I understand it is not a "smoothside", but it doesn't sound like a newer one with dual 2"/1.25" barrel.
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Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
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Tom Trusock
Reged: 02/26/02
Posts: 27405
Loc: Alternate Reality (TM)
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Hi Mike,
Thanks!
The 7t1's never had dual barrels. Yours is one of the last t1's made.
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There are two theories to arguing with my wife. Neither one works.
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