Telescopes and Telescope Accessories from Celestron, Meade, iOptron, Zhumell and More at Telescopes.com
1-800-303-5873
GUEST#   0
Top Selling Telescopes

TeleVue 2.5x Powermate 1-1/4 Inch Barlow Lens

Item# TVU037
 
5.0

(3 Ratings)

Customer Q & A

Sale Price:

$199.98

List Price: $260.00
Save 23%
Free Shipping with Economy Service
or to get it as soon as Aug. 15th with FedEx 1 Day when you buy within

View All Shipping Options

with FedEx 1 Day when you buy today

View All Shipping Options

Qty
Add To Cart
  • Better choice than Barlows for 1.25-inch diagonals
  • Stands less than 3 inches out of focuser
  • Remains parfocal in all 1.25-inch diagonals and prisms
  • Requires minimal refocusing
Details & Dimensions
Guarantee & Returns

What's Included?

Barlow lens

Description

Tele Vue 2.5x Powermate 1-1/4 Inch
These models stand less than 3" out of your focuser and the 5x take 1¼" threaded filters. They are parfocal in ALL 1¼" diagonals and prisms. For this reason, they are highly recommended over standard Barlows for 1¼" refractors such as the Tele Vue Ranger.
Excellent with long eye-relief, 2" eyepieces. Using the 4x model, imagine the quality of a 35mm Panoptic at 8.8mm with 25mm of eye relief! The Powermate is NOT a Barlow so the Panoptic-Barlow Interface is not needed! The 2" Powermate fits all the way into 2" Star Diagonals, requiring minimal refocus compared to a 2" Barlow.
To understand the Powermate, we must first understand the Barlow lens. Barlows amplify the power of a telescope. They can be considered "focal reducers" for eyepieces, or "focal extenders" for objectives. Terence Dickenson, in his Barlow test report in Sky and Telescope, July 1997, says: "Technology has erased the old objections. A modern Barlow will not degrade your telescope's optics. Anyone telling you otherwise is using outdated information. Moreover, the highly regarded Nagler eyepieces and their clones have built-in Barlows, ample evidence that the lens is not some detrimental intruder." Thanks, Terence, for laying the myth of the degrading Barlow to rest.
A high quality Barlow must be properly designed and manufactured in order to avoid compromising a telescope's color and spherical aberration corrections. The "invisibility" of Tele Vue's 2-element Barlows has been noted in test reports in the astronomy magazines. However, by the nature of its negative power lens, a Barlow will do more than just increase magnification, regardless of the number of elements.
The diverging rays leaving the Barlow result in moving the exit pupil further out, thereby extending the eye relief. In short to medium focal length eyepieces the change is not noticeable. However, in the case of long focal length eyepieces, the increase can be significant and not without performance consequences.
Vignetting can occur due to the altered ray path, when the eyepiece's lenses are not large enough in diameter to allow all the rays to make it through. Shorter Barlows, or ones with too much magnification, only exacerbate the problem because the ray path entering the eyepiece is steeper.
We had to go beyond the Barlow concept to achieve the goal of a compact, high power, fully corrected image amplifier. The Powermate consists of a negative doublet plus a positive "pupil-correcting" doublet. This 4-element system provides the magnifying function of a Barlow without its limitations by restoring the field rays back to their original direction, as if the Powermate were not there. The result is a pure magnification increase.
Unique Benefits and Applications for Powermates
Vignetting, edge field aberrations and pupil movement - all introduced when using Barlows with long focal length eyepieces, are minimized.
Telecentric operation (field rays leave parallel to optical axis, unlike Barlow lenses which diverge rays). This is ideal for Hydrogen-alpha filter use such as with Daystar models.
High performance for image amplification, CCD or film (some of the finest Earth-based planetary imaging is being done with Powermates)
Flexible for visual and imaging with all types of telescopes and eyepieces. Essentially Parfocal, and with nearly constant magnification regardless of image distance behind top surface (except 5x model which increases 1x for every 35mm of image distance increase).
Higher magnifications are possible with high optical performance compared to "doubling up" Barlows.
All will reach parfocal point in star diagonals, except for the 2", 2x which comes very close.
In addition to full multi-coating, Powermates include other Tele Vue special touches such as safety undercuts where practical on the chrome barrel and captive lock screws that can't fall out, and filter threads. Our 100% QC program at f/4 insures that Powermates will add dramatic power (and NOTHING ELSE) to your favorite eyepieces.
If, for example, you own a 24mm Panoptic, you'll have the power of a 12mm focal length eyepiece with the 2.0x Powermate, 9.6mm with the 2.5x Powermate, a 6mm with the 4x Powermate, or a 4.8mm with the 5x Powermate!

 

CHOKING HAZARD - small parts may pose a risk to children under 6 yrs.

Supplier Sku:
PMT-2513
Shipping Restrictions:
Only ships in contiguous USA.

Dimensions & Specifications

Brand

TeleVue

Telescope Accessories Series

Powermates

TeleVue 2.5x Powermate 1-1/4 Inch Barlow Lens
TeleVue 2x Barlow Lens 1-1/4 Inch
$125.00
TeleVue 2x Barlow Lens 1-1/4 Inch
Celestron Telescope 2X Barlow Lens 1-1/4 Omni
$47.95
Celestron Telescope 2X Barlow Lens 1-1/4 Omni
Celestron X-Cel LX 2x Barlow Lens
$89.95
Celestron X-Cel LX 2x Barlow Lens
Celestron X-Cel LX 3x Barlow Lens
$89.95
Celestron X-Cel LX 3x Barlow Lens
Celestron 2 Inch Luminos 2.5x Barlow Lens
$119.95
Celestron 2 Inch Luminos 2.5x Barlow Lens

The Perfect Accessories

Customer Reviews

REVIEW SNAPSHOT®

by PowerReviews
TeleVue 2.5x Powermate 1-1/4 Inch Barlow Lens
 
5.0

(based on 3 reviews)

Ratings Distribution

  • 5 Stars

     

    (3)

  • 4 Stars

     

    (0)

  • 3 Stars

     

    (0)

  • 2 Stars

     

    (0)

  • 1 Stars

     

    (0)

Reviewed by 3 customers

Sort by

Displaying reviews 1-3

Back to top

(1 of 1 customers found this review helpful)

 
5.0

Really good with my Dob!

By antar8x

from Bogotá, Colombia

About Me Avid Adventurer

Verified Buyer

Pros

  • Strong Construction

Cons

    Best Uses

    • Astronomy

    Comments about TeleVue 2.5x Powermate 1-1/4 Inch Barlow Lens:

    I just try it last week and was really good!.. with my new hyperion 17mm, I had really fun with Mars!

     
    5.0

    Great Buy

    By Topher

    from Undisclosed

    Comments about TeleVue 2.5x Powermate 1-1/4 Inch Barlow Lens:

    Excellent quality. It greatly increases magnification with out compromising too much quality.

     
    5.0

    2.5 X Powermate

    By Wes Bergman

    from Undisclosed

    Verified Reviewer

    Comments about TeleVue 2.5x Powermate 1-1/4 Inch Barlow Lens:

    I use a 2.5X Powermate to increase magnification for planetary pictures with webcams and CCD cameras. Televue's Powermates improve magnification without distortion providing better results.

    Displaying reviews 1-3

    Back to top

    Customer Q & A

    Q1: I would like to purchase the 2.5x and 5x Televue Powermate Barlow Lens directly from your site but I live in Italy. Is it possible for you to ship these items to Italy? Best regards Lanciano Vincenzo Sesto Fiorentino - Italy

    A: Shipping these to Italy is not a problem. Simply place your order online and we will contact you via email regarding international payment details.

    Ask a Question  

    Don't see the answer you need? Ask a Product Expert! The answer will be emailed to you and then posted here.

    Satisfaction Guaranteed
    1-800-303-5873
    GUEST#   0
    Hayneedle, Inc., Internet Shopping, Omaha, NE
    Telescopes.com is a Hayneedle Inc. store. Copyright 2007 - 2014 , Hayneedle Inc., all rights reserved.