russell23
sage
Reged: 05/31/09
Posts: 402
Loc: Upstate NY
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Quote:
Interesting that not one post so far has listed the weight of the eyepieces they have discussed. ;<)
It reminds me of a comment I heard one night at a star party..."Does this eyepiece make my scope look fat?"
Considering that balancing a scope is a big issue, weight does matter.
Has anyone substituted a lighter weight barrel on a heavy eyepiece?
As I asked earlier - what weight do you consider too heavy? A 31mm T5 Nagler weighs 35oz, a 22mm T4 Nagler weighs 24oz. Is the 31mm heavy? The 22mm? Or how about a 27mm Panoptic at 16oz?
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jrbarnett
Eyepiece Hooligan
Reged: 02/28/06
Posts: 4258
Loc: Petaluma, CA
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Yes, yes and yes. 
Regards,
Jim
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"When you make the finding yourself - even if you're the last person on Earth to see the light - you never forget it."
- Carl Sagan
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Paul G
Carpal Tunnel
Reged: 05/08/03
Posts: 2190
Loc: Freedonia
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Quote:
Does anyone use carbon fiber in their eyepieces?
Not sure it would have a place in an eyepiece. If it replaced the aluminum housing there would be little weight savings, and the business end, the barrel, isn't appropriate for such a material. Imagine tightening the end of a setscrew into carbon fiber.
Plastic to replace the heavy barrel would make a significant difference and would be sturdy enough but might mar more easily. However, given all the whining you see here about the cost of large premium eyepieces can you imagine the howl if a $500 eyepiece were made of plastic? 
Heft gives the impression of quality. Heavy automobile doors that close with a thud are one example. Considerable engineering goes into making a quality-inspiring sound. The LS460's door was engineered to sound like a heavy oak door. My binoculars are another example of the impression weight makes. The Leicas are made of various metals and have a substantial feel in the hand, while the latest Zeiss of similar optical quality but with some type of composite body feel light and "cheap" despite their price.
And the large eyepieces have big chunks of glass. The 31 Nagler has one element that's larger than the objective of a Pronto.
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Gus
Tasco 4.5 Reflector EQ Telescope
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Jim Rosenstock
Post Laureate
Reged: 07/14/05
Posts: 3654
Loc: MD, south of the DC Nebula
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Quote:
It reminds me of a comment I heard one night at a star party..."Does this eyepiece make my scope look fat?"
That's the best line I've heard in a while!!!
If Dr. Freud were around, I'm sure he'd have a few things to say about this thread...
...once he removed his cigar, of course. 
Jim
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QUESTION AUTHORITY!
"errr....sez who??"
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nightstalker
sage
Reged: 03/30/07
Posts: 248
Loc: Great South Land
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Great thread .. My 8.5 pentax xf actually feels alarmingly light for its size , I've been quite concerned for it for some time now 
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28pretoria22t414xw8.5xf
12" truss dob and numerous missplaced accesories...graham
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gnowellsct
professor emeritus
Reged: 06/24/09
Posts: 617
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Balancing a scope IS a big issue, but you know, it is only an issue for SOME scopes. German equatorial/SCT configurations are fairly immune to many of the balance issues that plague dob users.
People who have servo go-to Dobs, which is a fair number of people these days, also are immune to the balance issue.
On my gem-mounted refractors I've never had to worry about balance.
If you have a refractor on a Gibraltar, you need to worry. And I have heard you need to worry on disc mount. I define worry as having to do anything.
Once I've set my scope or scopes up for the night, I'm done with the balance issue regardless of what eyepiece I put in. The most I might do is tighten, or loosen, a clutch.
So, to conclude, a lot of scope owners are not worrying about weight, and do not figure it into their calculations.
However, we pay for that in setup time. If you have a simple undriven dob you can set up fast, in some cases in a minute or so, but now you've got the eyepiece weight issue.
regards
greg n
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"Aperture will get you through times of no money better than money will get you through times of no aperture."
featuring selected astrojunk:
bunch o' widefield eyepieces
bunch o' narrowfield eyepieces
couple o' Barlows
couple o' scopes
couple o' mounts
couple o' tripods
and a pier 'n' stuff
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jrbarnett
Eyepiece Hooligan
Reged: 02/28/06
Posts: 4258
Loc: Petaluma, CA
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Imbalance is only one of several "ills" of excessively porky eyepieces.
A case full of eight-element eyepieces is heavy and adds to the hassle of loading and unloading as a result. A tall, heavy eyepiece is more apt to unscrew an SCT diagonal during a slew. A heavy eyepiece is more apt to damage itself on impact than a lighter one (hits with more force). Those are just a few examples.
The number of ills associated with lower weight eyepieces is smaller (like everything else about them ).
Regards,
Jim
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"When you make the finding yourself - even if you're the last person on Earth to see the light - you never forget it."
- Carl Sagan
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AlienFirstClass
professor emeritus
Reged: 02/13/09
Posts: 702
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Quote:
Quote:
Interesting that not one post so far has listed the weight of the eyepieces they have discussed. ;<)
It reminds me of a comment I heard one night at a star party..."Does this eyepiece make my scope look fat?"
Considering that balancing a scope is a big issue, weight does matter.
Has anyone substituted a lighter weight barrel on a heavy eyepiece?
As I asked earlier - what weight do you consider too heavy? A 31mm T5 Nagler weighs 35oz, a 22mm T4 Nagler weighs 24oz. Is the 31mm heavy? The 22mm? Or how about a 27mm Panoptic at 16oz?
It's like the old saying.."One can never be too rich or too thin"...or your eyepiece too light.
Lighter is better...much lighter is much better.
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AlienFirstClass
professor emeritus
Reged: 02/13/09
Posts: 702
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Quote:
Quote:
Does anyone use carbon fiber in their eyepieces?
Not sure it would have a place in an eyepiece. If it replaced the aluminum housing there would be little weight savings, and the business end, the barrel, isn't appropriate for such a material. Imagine tightening the end of a setscrew into carbon fiber.
Plastic to replace the heavy barrel would make a significant difference and would be sturdy enough but might mar more easily. However, given all the whining you see here about the cost of large premium eyepieces can you imagine the howl if a $500 eyepiece were made of plastic?
Heft gives the impression of quality. Heavy automobile doors that close with a thud are one example. Considerable engineering goes into making a quality-inspiring sound. The LS460's door was engineered to sound like a heavy oak door. My binoculars are another example of the impression weight makes. The Leicas are made of various metals and have a substantial feel in the hand, while the latest Zeiss of similar optical quality but with some type of composite body feel light and "cheap" despite their price.
And the large eyepieces have big chunks of glass. The 31 Nagler has one element that's larger than the objective of a Pronto.
Carbon fiber would work well...just like it does in OTAs.
Weight is weight...and it is undesirable in an eyepiece in relation to function.
Many of the comments sound like "these extra 20 pounds I am carrying on my waist actually serve a purpose" when the truth is that they affect the telescope in a negative manner.
When I assess eyepieces, their weight is taken into account since it affects the scope and mount.
As for setscrews having an effect, that is poor design of the focuser. Any focuser worth having has a compression ring to properly retain an eyepiece.
And a nasty habit people have is to overtighten their setscrews because...the eyepiece is too heavy and will fall out.
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Tamiji Homma
Pooh-Bah
Reged: 02/24/07
Posts: 1070
Loc: California, USA
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Quote:
Imbalance is only one of several "ills" of excessively porky eyepieces.
A case full of eight-element eyepieces is heavy and adds to the hassle of loading and unloading as a result. A tall, heavy eyepiece is more apt to unscrew an SCT diagonal during a slew. A heavy eyepiece is more apt to damage itself on impact than a lighter one (hits with more force). Those are just a few examples.
The number of ills associated with lower weight eyepieces is smaller (like everything else about them ).
Regards,
Jim
Here is datapoint, weight measurement of eyepiece without caps.
Those three eyepieces are very light for its focal length.
81.0 25.0 Zeiss-Asphical 1.25"
75.0 28.0 Siebert-UW 1.25"
68.0 23.0 SV23
Code:
gram focal name
958.0 28.0 WO-UWAN
771.0 30.0 BW-Optik/Zeiss
722.0 17.0 TV-Ethos
678.0 22.0 TV-Nagler
555.0 50.0 Tak-LE
530.0 42.0 Vixen-LVW
492.0 40.0 TMB-Paragon
424.0 3.5 Pentax-XW
390.0 10.0 Pentax-XW
358.0 20.0 Pentax-XW
354.0 31.0 Hyperion 2" mode
308.0 32.0 Edmunds-RKE
298.0 24.0 Hyperion 2" mode
291.0 30.0 TMB-Paragon
248.0 14.0 Denkmeier
237.0 16.0 WO-UWAN
179.0 19.0 TV-Panoptic
175.0 32.0 TV-Plossl
160.0 30.0 Tak-LE
150.0 3-6 TV-Nagler-Zoom 3-6
133.0 5.0 Tak-LE
131.0 3.6 Tak-LE
101.0 12.5 Tak-LE
89.0 5.1 Pentax-XO
84.0 16.0 ZAO2
81.0 25.0 Zeiss-Asphical 1.25"
75.0 28.0 Siebert-UW 1.25"
73.0 15.0 TV-Plossl
68.0 23.0 SV23
67.0 10.0 ZAO2
66.0 6.0 ZAO2
64.0 11.0 TV-Plossl
62.0 4.0 ZAO2
56.0 7.0 TMB-mono
Tammy
Edited by Tamiji Homma (07/03/09 02:50 PM)
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russell23
sage
Reged: 05/31/09
Posts: 402
Loc: Upstate NY
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Quote:
Quote:
Quote:
Interesting that not one post so far has listed the weight of the eyepieces they have discussed. ;<)
It reminds me of a comment I heard one night at a star party..."Does this eyepiece make my scope look fat?"
Considering that balancing a scope is a big issue, weight does matter.
Has anyone substituted a lighter weight barrel on a heavy eyepiece?
As I asked earlier - what weight do you consider too heavy? A 31mm T5 Nagler weighs 35oz, a 22mm T4 Nagler weighs 24oz. Is the 31mm heavy? The 22mm? Or how about a 27mm Panoptic at 16oz?
It's like the old saying.."One can never be too rich or too thin"...or your eyepiece too light.
Lighter is better...much lighter is much better.
Ok, but that doesn't really answer my question. At what weight (in grams or ounces) would you be satisfied that an eyepiece is not creating problems for you because of its weight?
This is not an irrelevant question. Your problem cannot be fixed until there is a target weight you're shooting for. If "the lighter the better" is your only criteria, then I'm sure somebody out there has some 0.965" eyepieces with plastic lenses they'd be willing to give away for the cost of postage.
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Starpoke
sage
Reged: 11/14/07
Posts: 275
Loc: Western Montana
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I have one that unbalances every scope I have tried it in, plus it really needs the safety groove because on a GEM the normal tube rotation as one slews puts enough torque on it to automatically point it to the ground. I am speaking of the 35mm. Scopos Extreme. It is not only heavy at 1090g. (38.2 oz.) but tall and wide as well. I have to move the Brandon forward about 2" when I put it in but it does have a nice sharp 70 degree field. I use it rarely because it feels so precarious but I love the 3.7 degree FOV. which is slightly larger but much darker than the 3.65 I get with the 48mm. Brandon ep. with its 50 degree field. I probably would be happier with the 36mm. Hyperion Aspheric. (Naglers and Pans are presently out of reach.)
It nearly doubles the weight of my WO 66 petzval but the 6 degree plus FOV is really nice.
Clear skies
Glenn
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152nn f9 Starfire Apo on Schaefer AT-4 Mount
94mm f7 Brandon Apo on ASGT (or Polaris when AGST is on the fritz.)
WO Zenithstar 66 f6 ED Pretzval on UA Microstar
Tasco 7TE-5 60mm. f16.7 EQ Refractor.
Celestron C-60E f15 on Polaris
Celestron CO 62 Cometron f5
Meade 390 90mm f11 on Mizar m-4
Tasco 8V
eyepieces, books, some old scopes and mounts - ect.
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Starpoke
sage
Reged: 11/14/07
Posts: 275
Loc: Western Montana
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The E.P. plus the Williams CF diagonal tips the scale at 3 lbs 7 oz.
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152nn f9 Starfire Apo on Schaefer AT-4 Mount
94mm f7 Brandon Apo on ASGT (or Polaris when AGST is on the fritz.)
WO Zenithstar 66 f6 ED Pretzval on UA Microstar
Tasco 7TE-5 60mm. f16.7 EQ Refractor.
Celestron C-60E f15 on Polaris
Celestron CO 62 Cometron f5
Meade 390 90mm f11 on Mizar m-4
Tasco 8V
eyepieces, books, some old scopes and mounts - ect.
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Starpoke
sage
Reged: 11/14/07
Posts: 275
Loc: Western Montana
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The scope is barely heavier at 3 lbs. 13 oz.
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152nn f9 Starfire Apo on Schaefer AT-4 Mount
94mm f7 Brandon Apo on ASGT (or Polaris when AGST is on the fritz.)
WO Zenithstar 66 f6 ED Pretzval on UA Microstar
Tasco 7TE-5 60mm. f16.7 EQ Refractor.
Celestron C-60E f15 on Polaris
Celestron CO 62 Cometron f5
Meade 390 90mm f11 on Mizar m-4
Tasco 8V
eyepieces, books, some old scopes and mounts - ect.
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AlienFirstClass
professor emeritus
Reged: 02/13/09
Posts: 702
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Quote:
Quote:
Quote:
Quote:
Interesting that not one post so far has listed the weight of the eyepieces they have discussed. ;<)
It reminds me of a comment I heard one night at a star party..."Does this eyepiece make my scope look fat?"
Considering that balancing a scope is a big issue, weight does matter.
Has anyone substituted a lighter weight barrel on a heavy eyepiece?
As I asked earlier - what weight do you consider too heavy? A 31mm T5 Nagler weighs 35oz, a 22mm T4 Nagler weighs 24oz. Is the 31mm heavy? The 22mm? Or how about a 27mm Panoptic at 16oz?
It's like the old saying.."One can never be too rich or too thin"...or your eyepiece too light.
Lighter is better...much lighter is much better.
Ok, but that doesn't really answer my question. At what weight (in grams or ounces) would you be satisfied that an eyepiece is not creating problems for you because of its weight?
This is not an irrelevant question. Your problem cannot be fixed until there is a target weight you're shooting for. If "the lighter the better" is your only criteria, then I'm sure somebody out there has some 0.965" eyepieces with plastic lenses they'd be willing to give away for the cost of postage.
No games...I gave you the answer.
Lighter is better.
I have a number of scopes so the "correct" weight would be different for each scope.
What's the right and only weight for you?
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russell23
sage
Reged: 05/31/09
Posts: 402
Loc: Upstate NY
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Quote:
Quote:
Quote:
Quote:
Quote:
Interesting that not one post so far has listed the weight of the eyepieces they have discussed. ;<)
It reminds me of a comment I heard one night at a star party..."Does this eyepiece make my scope look fat?"
Considering that balancing a scope is a big issue, weight does matter.
Has anyone substituted a lighter weight barrel on a heavy eyepiece?
As I asked earlier - what weight do you consider too heavy? A 31mm T5 Nagler weighs 35oz, a 22mm T4 Nagler weighs 24oz. Is the 31mm heavy? The 22mm? Or how about a 27mm Panoptic at 16oz?
It's like the old saying.."One can never be too rich or too thin"...or your eyepiece too light.
Lighter is better...much lighter is much better.
Ok, but that doesn't really answer my question. At what weight (in grams or ounces) would you be satisfied that an eyepiece is not creating problems for you because of its weight?
This is not an irrelevant question. Your problem cannot be fixed until there is a target weight you're shooting for. If "the lighter the better" is your only criteria, then I'm sure somebody out there has some 0.965" eyepieces with plastic lenses they'd be willing to give away for the cost of postage.
No games...I gave you the answer.
Lighter is better.
I have a number of scopes so the "correct" weight would be different for each scope.
It is hard then to understand what you're looking for when you started this thread. Was the point just to complain that some eyepieces are heavy? Which eyepieces? At what weight do they become a problem for you? What is your criteria for the weight being a problem? Because it causes balance problems with your mount? Problems for the focuser? Problems for the locking mechanism of the diagonal?
It just seems odd me that you would start this thread and then be so vague in describing what your problem is. It makes it very difficult for those of us that are actually interested in the question you raised to respond in anything other then generalities.
Quote:
What's the right and only weight for you?
This is much like what I asked you and it is not a hard question to answer. I have found that in my scope, any eyepiece that weighs more than ~16-17oz is too heavy to maintain the balance of the refractor in my mount if I switch to the other eyepieces I own.
The heaviest eyepiece I have is a 27mm Pan - which weights just over 16oz. I can use that along with any of the other 10 eyepieces I have and there are no significant balance problems in switching.
When I had a 38mm Orion Q70 - which weighs in at around 21-22oz, it was impossible to balance the OTA in the rings for the 38mm and then switch to my lighter eyepieces.
Of course the heavier eyepieces would not be a problem - if all of my eyepieces were heavier. So another solution to the problem would be rather than make eyepieces lighter - strive to make them heavier. I don't actually advocate that. The problem - for my scope set-up - is that if there are big differences in eyepiece weight it throws of the balance. In theory any eyepiece would be ok as long as I'm either not switching eyepieces or switching to eyepieces that have similar weight.
That explanation is quite a bit different than just saying "lighter is better". I agree with the sentiment, but at some point physics, optical design, and quality get in the way.
Someone mentioned earlier that they felt the Naglers are made of heavier barrel construction than needed. And that may be so. I'm hesitant to pick up a 22T4 Nagler because it weights 24oz. If it could be pared down to 16oz with lighter barrel materials that would interest me.
I wonder if the TV lense assemblies could be put into a Delrin type housing such as that Gary Russell (no relation) uses in his eyepieces?
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russell23
sage
Reged: 05/31/09
Posts: 402
Loc: Upstate NY
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Let me add one other thought here too. In the case of the scope and mount I'm using, lighter is not necessarily better. If I use really light eyepieces, I have to drop the tube further back in the rings so that the objective does not overwhelm the star diagonal/eyepiece. So in that situation a lighter eyepiece forces the diagonal closer to the ground - which can be less comfortable. When I put in a heavier eyepieces, the tube is placed such that the eyepiece can be higher above the ground.
I can also adjust for this by adjusting the legs, but the point is lighter can create its own problems.
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AlienFirstClass
professor emeritus
Reged: 02/13/09
Posts: 702
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Actually you raise another good point...why isn't there a predefined weight that all eyepieces are designed to?
If there was ONE weight, all scope assemblies could be set to balance on that one value and using a scope would be much simpler.
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Starman1
Vendor - Scope City
Reged: 06/24/03
Posts: 12168
Loc: Los Angeles
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Doesn't this depend on whether the scope is balanced for a certain weight at a certain point? With my lightest eyepiece and the scope pointed near zenith, I have to dangle a counterweight from the UTA of my scope.
With a 31 nagler at the horizon, I have to add a 5lb counterweight to the mirror box.
There is NO weight that would be perfectly balanced near the zenith AND the horizon, so some form of counterweight will always be necessary unless the scope is so large the weight of the eyepiece is insignificant, or so "sticky" that the difference in the weight of eyepieces causes no noticeable balance changes.
--------------------
Don Pensack
12.5" Truss Dob, 5" Maksutov, Fujinon Binos
Sustaining Lifetime IDA member
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Tamiji Homma
Pooh-Bah
Reged: 02/24/07
Posts: 1070
Loc: California, USA
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Quote:
Actually you raise another good point...why isn't there a predefined weight that all eyepieces are designed to?
If there was ONE weight, all scope assemblies could be set to balance on that one value and using a scope would be much simpler.
Because size/weight/shape of telescope/mount etc are vastly different as primary eyepiece design parameters (focal length, AFOV, eye relief, glass, cost, ...) are vastly different.
If you demand optical engineers "one size fits all or telescope balancing issue by eyepiece" type requirement as mandatory design parameter, I suspect you will be disappointing result of product in terms of optical quality, mechanical robustness, price etc.
I believe free to design anyway you want is much better solution so that we consumers can choose whatever our liking 
If you sort my weight measurement in eyepiece focal length, it tells something: Some eyepiece weight is more than 10x than other with the same focal length.
Code:
Partial list where it is interesting:
grams F/L model name
237.0 16.0 WO-UWAN
84.0 16.0 ZAO2
722.0 17.0 TV-Ethos
179.0 19.0 TV-Panoptic
358.0 20.0 Pentax-XW
678.0 22.0 TV-Nagler
68.0 23.0 SV-Plossl
298.0 24.0 Hyperion
81.0 25.0 Zeiss-Ortho
75.0 28.0 Siebert-UW
958.0 28.0 WO-UWAN
771.0 30.0 BW-Optik/Zeiss
291.0 30.0 TMB-Paragon
160.0 30.0 Tak-LE
354.0 31.0 Hyperion
308.0 32.0 Edmunds-RKE
175.0 32.0 TV-Plossl
Tammy
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