Televue 4x Powermate Lens 2" with 1.25" Adapter - Boxed S

In nice clean used condition
 

Details from web below:

Concept: While Barlows are powerful tools, the negative element defining them also limits their ability. The simple negative element Barlow increases eyepiece eye-relief. With short focal length eyepieces the effect is negligible. However, on long focal length eyepieces the exit pupil position moves well beyond the designer's intended position, resulting in vignetting with many eyepieces. This is why "Shorty" Barlows in particular, with their strong negative element often vignette and degrade long focus eyepieces. My 4-element form picks up where the Barlow concept can go no further. Powermate™ is a technically universal solution, using a positive field lens to redirect field rays. The result is an exit pupil that stays where the eyepiece designer intended. With freedom from aberrations, greater magnification potential, and compact size, I hope you'll agree Powermate™ raises the standard for image amplification. Al Nagler

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™ -- see below).
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!

Imaging the Solar System with Powermates™

Some of the finest Solar System images have been made with Powermates. Used singly or stacked, Powermates™ help any scope achieve the long focal-length required to image details on Solar System bodies. The increased image scale allows for imaging without an intervening eyepiece -- like in prime focus photography.

---

Please note:
Only accessories listed in the photograph's are included with the purchase unless otherwise stated.

Photographs are taken by ENS and aren't manufacturer stock images unless otherwise stated.

For any specific enquiries then please use our contact form and quote the product id.