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Equipment Discussions >> Eyepieces

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Phillip Creed
Idiot Seeking Village
*****

Reged: 07/25/06

Loc: Canton, OH
Re: 14mm Delos just arrived! new [Re: Starman81]
      #5695566 - 02/22/13 08:23 PM

Quote:

[So that leads me to believe that you cannot achieve a true 20mm ER eyepiece once you go beyond the 20mm focal length WITHOUT going to a 2" barrel (like Phil suggested for TeleVue to do). But once you go up to that 2" barrel, look what TeleVue already has in their lineup, the Nagler 22T4 with 19mm ER! Would they cannibalize the 22T4 sales and release a 2" Delos 22 or 24mm eyepiece that has 1 more mm of ER and 10 deg less AFOV??




Syed,

I agree that it doesn't make sense for Televue to make a 22mm Delos, with a 22T4 in the line-up.

Different story if you're talking 20mm or 24mm, though. There are no Televue offerings there that have ample eye relief, and the 19mm and 24mm Panoptics are part of a design that's getting a little long in the tooth. The 20T5 is a sharp eyepiece, but again, its 12mm of eye relief is a deal-killer if you wear glasses.

If Televue's going to make a move into 2" Deloi, 20mm and 24mm would seem to be the logical places to do it. The 20XW has field curvature issues, and if the persistent rumors of the XW's demise turn out to be true (at least, eventually; there's been so many rumors, proclaimations of its demise and, yet, it soldiers on. It's like the Rasputin of eyepiece lines), there will be some pent-up demand for a 20mm eyepiece with long eye relief.

Beyond 24mm, the T5 Naglers and Panoptics have more than enough eye relief.

Clear Skies,
Phil


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Dave M
Postmaster
*****

Reged: 08/03/04

Loc: Ohio
Re: 14mm Delos just arrived! new [Re: Phillip Creed]
      #5696365 - 02/23/13 11:03 AM

A 2" 24mm Delos would be Nice!

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Phillip Creed
Idiot Seeking Village
*****

Reged: 07/25/06

Loc: Canton, OH
Re: 14mm Delos just arrived! new [Re: Dave M]
      #5696636 - 02/23/13 01:42 PM

A 2" 24mm Delos would have a 30-31 mm field stop, close to the field stop size on either the 22T4 Nagler or the 27mm Panoptic.

Oh, and it'd have 20mm of eye relief, if you need it, vs. the 15mm ER on the 24-Pan. There's that.

I don't think Televue would do away with the 24 Pan, even if they did do a 24mm Delos. The 24 Pans are favorites among those with binoviewers due to the small size. A 24mm Delos would be...any antonym of "small".

Clear Skies,
Phil


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Deep13
Carpal Tunnel
*****

Reged: 01/25/05

Loc: NE Ohio
Re: 14mm Delos just arrived! new [Re: John Rhodes]
      #5696656 - 02/23/13 01:54 PM

Quote:

nor making the 17.3 and 14mm Delos into bulkier, more expensive, 2" models (with no benefit in TFOV),




So for those with a low-profile focuser, it essentially is a 2" EP, except the user has to incur the cost by purchasing an adapter. If one has a low-profile 1.25" focuser (not common, I know) there is no way to use it.


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Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: 14mm Delos just arrived! new [Re: Deep13]
      #5696886 - 02/23/13 04:00 PM

They'd have to correct it somehow for fast scopes because the coma would be immense in any size over the 17.3mm Delos.

Unless you use a Paracorr, then you'd be good to go.

Cheers,


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John Rhodes
Vendor (Televue Rep)
*****

Reged: 02/21/06

Loc: Torrance, CA.
Re: 14mm Delos just arrived! new [Re: John Rhodes]
      #5790453 - 04/10/13 02:24 PM

Quote:

Quote:


(2) I'm grateful that the Orion 8" f/4.9 is a dual photo/visual instrument. These tend to require extension tubes to get most eyepieces to focus. Most. The 14mm Delos, though, requires significantly more infocus than the 10mm Delos, so I just took off the extension tube. I don't know the exact amount, but it's not a smidge; it's a lot.
Clear Skies,
Phil




Phillip, All,
I asked David about this issue. Here's his response:
 
The 17.3mm and 14mm Delos could not be designed to be parfocal with the other 1.25" parfocal Delos, Plossl, Nagler and Panoptic eyepieces because of the limitation of the 1.25" barrel diameter. Not wishing to compromise the optical quality in any way, nor making the 17.3 and 14mm Delos into bulkier, more expensive, 2" models (with no benefit in TFOV), we elected to have them require more in-travel than the others.
 
If your current 2" focuser, with 1.25" adapter, does not have enough in-travel to reach focus with the 17.3mm and 14mm Delos, Tele Vue will shortly be offering a "below-profile" 2" to 1.25" adapter that will greatly reduce focuser in-travel.  Since the 1.25" barrel will be positioned within the 2" drawtube, the adapter will lock onto the eyepiece using a nylon-tipped set screw.
 
For Paracorr type 2 users, the adapter was designed to parfocalize the 17.3mm and 14mm Delos with other 1.25" parfocal Tele Vue eyepieces (when they're used with the 1.25" adapter supplied with the Paracorr).  The 17.3mm and 14mm Delos will, therefore, conveniently use the same Paracorr setting as all other parfocal 1.25" Tele Vue eyepieces.
 
In other applications, such as refractors and SCT's, the special 2" adapter will make the 17.3mm and 14mm Delos close to parfocal with other parfocal 1.25" Tele Vue eyepieces when they are used with our "high-hat" type 2" to 1-1/4" adapter.




Group,
This adapter is now in stock and available at your favorite dealer !


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Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: 14mm Delos just arrived! new [Re: John Rhodes]
      #5790485 - 04/10/13 02:40 PM

Hi John,

Does the adapter come with the 17.3mm Delos? Or do you have to order it as an extra?

Cheers,


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John Rhodes
Vendor (Televue Rep)
*****

Reged: 02/21/06

Loc: Torrance, CA.
Re: 14mm Delos just arrived! new [Re: Scanning4Comets]
      #5790502 - 04/10/13 02:49 PM

Quote:

Hi John,

Does the adapter come with the 17.3mm Delos? Or do you have to order it as an extra?

Cheers,




Hi Markus,
Order as an extra... because some scopes don't need it..


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Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: 14mm Delos just arrived! new [Re: John Rhodes]
      #5790566 - 04/10/13 03:30 PM

John,

Wouldn't the 17.3mm Delos need an extra 1/2" of in travel no matter what scope was used?


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Alvin Huey
Carpal Tunnel
*****

Reged: 10/18/05

Loc: NorCal
Re: 14mm Delos just arrived! new [Re: Scanning4Comets]
      #5790694 - 04/10/13 04:45 PM

Quote:

John,

Wouldn't the 17.3mm Delos need an extra 1/2" of in travel no matter what scope was used?




...but most scopes have that 1/2" in travel like all of my scopes.

It is designed primarily for those who doesn't have enough in travel.


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Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: 14mm Delos just arrived! new [Re: Alvin Huey]
      #5790846 - 04/10/13 05:34 PM

Ah yes,

I never thought of that Alvin, lol.

Cheers,


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GeneT
Ely Kid
*****

Reged: 11/07/08

Loc: South Texas
Re: 14mm Delos just arrived! new [Re: Phillip Creed]
      #5791026 - 04/10/13 06:37 PM

I recently bought a 14 Delos, but only had time to give it a light work out. I spent several hours comparing my new Pentax 5 XO and Pentax 5 XW, and my Delos 8 and 6 vs. my Pentax 7 XW. When I have a chance to give the 14 Delos more eyepiece time, I will update.



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Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: 14mm Delos just arrived! new [Re: GeneT]
      #5791121 - 04/10/13 07:36 PM

That will be great Gene! Looking forward to your report on the 14mm Delos.

cheers,


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