Televue 4X Powermate - 2"
•Televue Power Mate 4X Image Amplifier PMT-4201accepts all 2" eyepieces and accessories and comes with an additional 1.25" adapter!
•Incorporates a "positive" and "negative" doublet for better optical correction.
•Higher magnifications are possible with high optical performance compared to "doubling up" Barlows.
•Televue Power Mate 4X Image Amplifier PMT-4201delivers high performance for CCD or film!
•Accepts Televue's T-Ring Adapter (PTR-4201) for close coupling to cameras and CCD imagers.
•Ideal for Hydrogen-alpha filter use such as with Daystar models.
Televue 4X Powermate Image Amplifier - 2"
"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
The new Televue 4X Powermate PMT-4201 is 4-element concept which continues the tradition of full-field sharpness with optimum aberration control. Are you looking for long eye-relief? The Televue PMT-4201 retains the eye-relief of long focal length eyepieces, while at high power... a bonus for all eyeglass wearers! What makes it special? The Tele Vue Power Mate™ 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 Power Mate wasn't there. The result is a pure magnification increase! The 4X Televue PMT-4201 is flexible for visual and imaging with all types of telescopes and eyepieces. Essentially parfocal, the Televue PMT-4201 PowerMate delivers nearly constant magnification regardless of image distance behind top surface. Vignetting, edge field aberrations and pupil movement are minimized. No special interface is needed!
For astro-imagers, check the "Additional Images" tab for a chart which indicates the magnification as a function of distance from the Televue Powermate™ top surface to the imaging surface (CCD or film). Some of the finest Solar System images on this world have been made with Televue Powermates! Used singly or stacked, they help any scope achieve the long focal-length required to image details on the planets or solar surface. The increased image scale allows for imaging without an intervening eyepiece -- like in prime focus photography.
Televue 4X Powermate Image Amplifier Features...
•Four element design delivers full-field sharpness with optimum aberration control.
•Retains the eye-relief of long focal length eyepieces while delivering high power.
•Flexible for visual and imaging with all types of telescopes and eyepieces.
•4X - 2" Power Mate weighs 22 ounces.
•One year Televue warranty.
Televue Product Number MT-4201
All Televue products are available to ship world-wide from OPT, and effective July 1, 2008, are covered by a Five Year Worldwide Limited Product Warranty! Always be sure to save your original packaging materials should you need to return any Televue product for warranty or repair.
商品链接：http://item.taobao.com/item.htm? ... id=20700392996& |
置顶卡
变色卡
千斤顶
显身卡