Televue

[John]

1 hour ago, jetstream said:

I figure its a to each your own situation, lots of eyepieces to choose from for sure.

Indeed.

I didn't get on with the Leica ASPH zoom when I had one and the VIP barlow, but others feel it's the best eyepiece they have

Tonights star perfomers for me on Saturn, Jupiter and the Moon with my ED120 refractor were the 6mm Ethos and 4.7mm Ethos SX. Wonderful views and relaxing to use as well 

[Mr Spock]

I've had a few TV eyepieces - T4 and T7 Naglers, Radians and looked through others' Ethos (I can't afford such beasts). They were all excellent. I especially like the build quality.

But for my observing now, I find the LVWs more comfortable for general use and Circle-T Orthos crisper and cleaner for planetary.

[Louis D]

8 hours ago, Mr Spock said:

I've had a few TV eyepieces - T4 and T7 Naglers

Better hold onto those never released T7 Naglers.  They've got to be worth a fortune due to their rarity. 😉

[Mr Spock]

lol, typo - a T6 7mm 

[Louis D]

2 hours ago, Mr Spock said:

lol, typo - a T6 7mm 

I know, but still, we can dream someone got a hold of a T7 prototype (or the mythical T3).

[Voyager 3]

5 hours ago, Louis D said:

I know, but still, we can dream someone got a hold of a T7 prototype (or the mythical T3).

T0 ? 😎

[Louis D]

15 minutes ago, Voyager 3 said:

T0 ? 😎

The original 13mm Nagler prototype?

Look on these webpages for images of the T1's predecessor (I can't link the images because they're not https).

[Alan White]

Have we mentioned Undercuts yet?

Televue have a love of them, I don’t, tried to discuss with David Nagler, but he was not having it that they catch.

I made my mind up then on the spot, a company refusing to listen to customer feedback is not destined for my custom, so my TV eyepieces went except my Nagler Zoom, it’s undercut is Pentax like in proportion.

Yes they have great products, but flawed with the undercut.

 

 

[John]

1 hour ago, Alan White said:

Have we mentioned Undercuts yet?

Televue have a love of them, I don’t, tried to discuss with David Nagler, but he was not having it that they catch.

I made my mind up then on the spot, a company refusing to listen to customer feedback is not destined for my custom, so my TV eyepieces went except my Nagler Zoom, it’s undercut is Pentax like in proportion.

Yes they have great products, but flawed with the undercut.

 

 

Personally speaking, I have never found undercuts an issue with the dozens of eyepieces (or many brands) that I've owned, used and tested for the forum

I would certainly never allow the presence (or absence) of an undercut to dissuade me from a brand with so many other superb qualites. It's just a non-issue for me.

I realize that others will differ in that though and so be it - many pages of posts on forums have been fueled in the discussion of the things

Over recent years Tele Vue's undercuts have had a taper applied to the top lower edge of the undercut on most of their ranges, so it's not as if they have been totally stubborn over it.

 

Edited August 26, 2021 by John

[Alan White]

On 26/08/2021 at 09:59, John said:

Personally speaking, I have never found undercuts an issue with the dozens of eyepieces (or many brands) that I've owned, used and tested for the forum

I would certainly never allow the presence (or absence) of an undercut to dissuade me from a brand with so many other superb qualites. It's just a non-issue for me.

I realize that others will differ in that though and so be it - many pages of posts on forums have been fueled in the discussion of the things

Over recent years Tele Vue's undercuts have had a taper applied to the top lower edge of the undercut on most of their ranges, so it's not as if they have been totally stubborn over it.

 

I think the newer, higher raked and deeper undercut is worse than the older one to be honest.
I found they snagged in my Televue Diagonals more than anything else.

As you say its a pesraonal thing, but something that grates and makes your observing less enjoyable had to be addressed.

Edited August 30, 2021 by Alan White

[John]

7 minutes ago, Alan White said:

.... something that grates and makes your observing less enjoyable had to be addressed.

If it did for me, I would address it. I don't hang on to equipment that annoys me.

 

[JeremyS]

1 hour ago, Alan White said:

Have we mentioned Undercuts yet?

Televue have a love of them, I don’t, tried to discuss with David Nagler, but he was not having it that they catch.

I made my mind up then on the spot, a company refusing to listen to customer feedback is not destined for my custom, so my TV eyepieces went except my Nagler Zoom, it’s undercut is Pentax like in proportion.

Yes they have great products, but flawed with the undercut.

 

 

Funnily enough I just posted on undercuts on my Gemma thread, Alan.

Parfocalising rings on TV eyepieces might be the answer to the undercut nightmare. I did an experiment last night.

Maybe I won’t need to offload my TV eyepieces after all 🤔

[John]

"....the undercut nightmare..." 🤣🤣🤣

Oh boy

[JeremyS]

22 minutes ago, John said:

"....the undercut nightmare..." 🤣🤣🤣

Oh boy

Made me chuckle too, John 🤣

[RT65CB-SWL]

13 hours ago, Louis D said:

I know, but still, we can dream someone got a hold of a T7 prototype (or the mythical T3).

Maybe 'T7' was the top secret pre-production codename for this...

...the 'mythical' Apollo 11.

Edited August 26, 2021 by Philip R

[Stu]

My 24mm Panoptic used to be a right pain in the Tak prism. It used to get completely stuck and took quite a lot of persuading out.

I resolved it by filling the undercut with a wrap or two of insulating tape. Clamping the prism tightly over it compressed the tape and I had no further problems.

[Mr Spock]

Eyepieces costing hundreds of pounds should not need tape to make them useable!

[Mr Spock]

1 hour ago, Philip R said:

...the 'mythical' Apollo 11.

They are real - if you can find one.

So, if you thought they were a myth, I can say for certain you were mythtaken...

[John]

1 hour ago, Mr Spock said:

Eyepieces costing hundreds of pounds should not need tape to make them useable!

They don't. The Tak compression system is not good - I really don't like mine even with  barrels with no undercut. Fortunately my actual eyepieces go into an excellent Baader adapter which uses lateral pressure rods and handles all profiles of eyepiece barrel without any drama.

Otherwise I use Moonlite, Tele Vue and Astro Physics compression ring eyepiece holders all of which also seem to cope with undercuts.

 

 

 

Edited August 26, 2021 by John

[Stu]

7 minutes ago, John said:

They don't

Well…. They unfortunately do if you want to use them with a Tak prism without problems. It worked fine after doing that, but I’ve now sold the prism and like you have Baader Clicklock on my diagonals/prisms now, apart from the Televue Everbrite. Perhaps I can remove the tape now 🤪🤪🤣

[globular]

Most diagonals allow the eyepiece holder to be screwed off; And baader make lots of threads for their clicklocks. This means you can keep your Tak prism but with a more robust and undercut friendly holder.

[John]

11 minutes ago, Stu said:

Well…. They unfortunately do if you want to use them with a Tak prism without problems. It worked fine after doing that, but I’ve now sold the prism and like you have Baader Clicklock on my diagonals/prisms now, apart from the Televue Everbrite. Perhaps I can remove the tape now 🤪🤪🤣

Given that the majority of eyepieces have undercuts or tapers machined into their barrels and have done for years now, maybe it's Tak that need to re-think their clamp ?

I guess the Tak system would also struggle with their own UW eyepiece barrels as they mirror the Tele Vue design

 

[Stu]

2 minutes ago, John said:

Given that the majority of eyepieces have undercuts or tapers machined into their barrels and have done for years now, maybe it's Tak that need to re-think their clamp ?

I guess the Tak system would also struggle with their own UW eyepiece barrels as they mirror the Tele Vue design

 

I don’t disagree John, the Tak system is flawed and should be redesigned. I was just making what I had work together…

[johnturley]

31 minutes ago, John said:

They don't. The Tak compression system is not good - I really don't like mine even with  barrels with no undercut. Fortunately my actual eyepieces go into an excellent Baader adapter which uses lateral pressure rods and handles all profiles of eyepiece barrel without any drama.

 

 

No problem whatsoever using Tele Vue eyepieces (with their undercuts) with the Baader Click Lock accessories and adaptors.

John   

[Don Pensack]

If the undercuts are somewhat of a problem in your equipment, then filling the undercuts with metal tape is an easy fix, and it can be undone to sell them.

Personally, I prefer smooth barrels and a focuser drawtube that is smooth with no compression ring or collet, just thumbscrews to tighten down on the inserted item.

It leaves marks.  Oh, horrors?  Who cares?  I don't buy eyepieces thinking I'm going to resell them anyway.

The newer tapered edge undercuts TeleVue uses are less of a problem than the earlier sharp-edged ones.

The conically-tapered undercuts on a lot of recent eyepieces (ES, et.al.) are a real problem for the split ring binders found in most focusers and star diagonals.

The metal band is twisted, often permanently, by tightening down on the slanted surface.  ES went to stiff stainless steel split rings instead of brass in their focusers and star diagonals.

Collets (as in many adapters) that tighten uniformly around the perimeter can solve some undercut problems, but they don't tighten on the barrel at the bottom of the undercut

and, if they are the type with small metal rods, can actually get caught in the undercuts.

 

However, face facts.  Almost no modern eyepieces lack undercuts of one sort or another, so limiting your purchases only to smooth barrels is only hurting yourself.

So figuring out how to deal with undercuts is part of the hassle of using contemporary astronomy equipment.

I deal with it by filling the undercuts with metal tape, eliminating the split ring binders (remove them if they're there) in favor of thumbscrews or collets, and having a few eyepieces without

the safety undercuts and using a focuser with a smooth bore, a combination of all 4 solutions.

 

I had one adapter that had an undercut that always caught, and it had a tapered cylindrical undercut.  I taped it and it slides in an out without issue.  

So I wouldn't remove the tape if its presence make the item work well.  You might regret it.