76 replies to this topic

[jrmacl]

I started this hobby wanting to take pretty pictures.  Recently, as in this year, I decided to up my visual game.  So, much new to this aspect.  Apologies if this is a silly question, but...

 

What is an “undercut” eyepiece? 

some eyepieces are sold with a groove in the barrel to help the set screw catch, and some people do not like undercuts because of the way they catch and get hung up in their diagonals and especially bino-viewers. Televue is now releasing the new 24mm Pans and other ep's without undercuts and it is a huge deal for some people

Edited by jrmacl, 01 May 2025 - 03:11 PM.

[Tulsa]

some eyepieces are sold with a groove in the barrel to help the set screw catch, and some people do not like undercut because of the way they catch and get hung up in their diagonals and especially bino-viewers. Televue is now releasing the new 24mm Pans and other ep's without undercuts and it is a huge deal for some people

Thank you sir. 

[Mike W]

46 days and counting! LOL

[scotsman328i]

I started this hobby wanting to take pretty pictures.  Recently, as in this year, I decided to up my visual game.  So, much new to this aspect.  Apologies if this is a silly question, but...

 

What is an “undercut” eyepiece? 

Top image has the ‘undercut’ (channel in the barrel)

Bottom image is a smooth barrel 

Attached Thumbnails

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[Tulsa]

That’s what it looks like.  Not how I imagined it.  Both my Nagler 9mm’s have that undercut.  It’s a bit annoying but considering what we’re paying, to keep them from dropping accidentally, I can put up with a small annoyance. 

 

Thank you sir! 

[scotsman328i]

That’s what it looks like.  Not how I imagined it.  Both my Nagler 9mm’s have that undercut.  It’s a bit annoying but considering what we’re paying, to keep them from dropping accidentally, I can put up with a small annoyance. 

 

Thank you sir! 

Some folks hate them, others love them. Then you got folks like me that could care less if an eyepiece comes with an undercut or not. lol.

Edited by scotsman328i, 01 May 2025 - 04:55 PM.

[25585]

I started this hobby wanting to take pretty pictures.  Recently, as in this year, I decided to up my visual game.  So, much new to this aspect.  Apologies if this is a silly question, but...

 

What is an “undercut” eyepiece? 

Its where a seller lowers their sales price below that of another seller, hoping to sell more overall.

[scotsman328i]

It’s where a seller lowers their sales price below that of another seller, hoping to sell more overall.

25585, hahahaa, too funny.

[jrmacl]

That’s what it looks like.  Not how I imagined it.  Both my Nagler 9mm’s have that undercut.  It’s a bit annoying but considering what we’re paying, to keep them from dropping accidentally, I can put up with a small annoyance. 

 

Thank you sir! 

well if those undercuts on your 9mm T6's get too annoying for you then you are in luck, the new 9mm T7's have smooth barrels

[scotsman328i]

well if those undercuts on your 9mm T6's get too annoying for you then you are in luck, the new 9mm T7's have smooth barrels

Yeah, with even more gravity working with the 9T7 to pull it out of the focuser or diagonal, than the 9T6. lol.

[Look at the sky 101]

Hello Scout.

None of my favorite U.S.A. and Candian based Vendors have the 24 Panoptics in stock all "Back Ordered" but depending how bad you really want one TS Optik, and APM out of Germany still have a few. I checked Ebay for a 24 panoptic and none are listed used but there is a rare 26 Nagler listed, it took me two years to find one.

 

https://www.teleskop...eld-of-view-881

 

https://www.apm-tele...noptic-eyepiece

 

HAPPY SKIES AND KEEP LOOKING UP Jethro

It is in stock at the Maison de l'Astronomie in Montreal.

https://maisonastron...ptic-1-25-quot/

[jrmacl]

Yeah, with even more gravity working with the 9T7 to pull it out of the focuser or diagonal, than the 9T6. lol.

that's where the 17 sheets of bubble wrap come into play

[betacygni]

Yeah, with even more gravity working with the 9T7 to pull it out of the focuser or diagonal, than the 9T6. lol.

That’s what I never understood about eyepiece undercuts, how often is the eyepiece upside down where it could even potentially fall out. Not with most dobs or any scope on an alt/az setup. I suppose occasionally on an EQ as it slews, but those don’t seem that common for visual these days. I seem to emerged victorious in my righteous anti-undercut crusade, so I can let it go now and rest easy. My watch has ended.

Edited by betacygni, 01 May 2025 - 07:43 PM.

[Mike W]

In a refractor if your diagonal slips sideways it's good insurance. Don't tell me that has never happened. 

[scotsman328i]

In a refractor if your diagonal slips sideways it's good insurance. Don't tell me that has never happened. 

Oh, it’s happened. Happened a few times until I learned the 100mph tape mod.

[scotsman328i]

That’s what I never understood about eyepiece undercuts, how often is the eyepiece upside down where it could even potentially fall out. Not with most dobs or any scope on an alt/az setup. I suppose occasionally on an EQ as it slews, but those don’t seem that common for visual these days. I seem to emerged victorious in my righteous anti-undercut crusade, so I can let it go now and rest easy. My watch has ended.

I dunno man, sometimes I view with my diagonal at the 3 o clock or 9 o clock position in the focuser of my refractors.

[Mike W]

I dunno man, sometimes I view with my diagonal at the 3 o clock or 9 o clock position in the focuser of my refractors.

Exactly, southern Sagg. or Scorpius.

Edited by Mike W, 01 May 2025 - 08:20 PM.

[scotsman328i]

Exactly, southern Sagg. or Scorpius.

Big time…to name just a COUPLE! 

Where I am? Omega Cent also.

[Mike W]

Omega not really visible from 42*.

[Jon Isaacs]

 

Oh wow. Why away from the BCRs? I wonder if that will cause an uproar. I own a 2001 Televue 76 and a 2000 Televue 102. Both of them have single hardened steel set screws in their focusers.

 

My TeleVue stuff has either had a brass "compression ring" or an aluminum thumbscrew.

 

 If I have issues, I replace them with nylon thumbscrews. They're 10-32's and I bought a half pound of the for 10 bucks. I given quite a few away but I have over 200 left.

 

Jon

[scotsman328i]

My TeleVue stuff has either had a brass "compression ring" or an aluminum thumbscrew.

 

 If I have issues, I replace them with nylon thumbscrews. They're 10-32's and I bought a half pound of the for 10 bucks. I given quite a few away but I have over 200 left.

 

Jon

I could be wrong, Jon. Maybe those thumbscrews are aluminum and not steel. I also got a bunch of 10/32s, M5s and others in nylon and metal. Mainly replaced metal with the nylon ones. 

[25585]

I could be wrong, Jon. Maybe those thumbscrews are aluminum and not steel. I also got a bunch of 10/32s, M5s and others in nylon and metal. Mainly replaced metal with the nylon ones. 

Test with a magnet.

[scotsman328i]

Test with a magnet.

In absolute honesty?…I would…if I cared. 

Edited by scotsman328i, 02 May 2025 - 02:05 PM.

[scotsman328i]

Looks like the drought is over. A 24mm Panoptic is forecasted to pop up in the classifieds very soon. 

Haha, I’m thinking that also. 

[Mike W]

Well the 47 day streak has been broken!