Barlow et teleXtender

[K1200LT 7]

bonjour, je reprends l'astro aprés plusieurs années d'inactivité dans ce domaine. Je vais tenter l'imagerie CCD. J'aurais besoin d'un renseignement: quelle est la différence entre une Barlow (j'ai une 2x et une 3x) et un teleXtender svp ? Merci d'avance d'éclairer ma lanterne. Cordialement.

[K1200LT 7]

ne cherchez plus, j'ai eu la reponse via un forum US.

[JP-Prost 1 848]

Bonjour

certes, mais il serait intéressant d'avoir nous aussi la réponse que tu as lue ....

JP

[K1200LT 7]

Hi dear french friend, extract from advertised Meade:

This new Series 5000 Ultra TX “TeleXtender" is an updated version of a Barlow lens. While called a “TeleXtender" by Meade, it should not to be confused with the tele-extender camera adapter used for eyepiece projection astrophotography with catadioptric telescopes.
This Meade uses an advanced four-element optical design that delivers a flatter field-of-view with sharper field edges than even the best three-element apochromatic Barlows. All air-to-glass surfaces of its four premium optical glass lenses are fully coated with multiple layers of individually tuned ion-deposited anti-reflection materials for maximum light transmission and contrast. The lens edges and all internal metal surfaces are blackened to maximize the image contrast. Eyepieces are held in the “TeleXtender" by a non-marring clamp ring that won’t scratch your eyepieces as a conventional metal thumbscrew can. A safety groove machined into the instrument’s chrome barrel keeps the “TeleXtender" and eyepiece from falling should the focuser thumbscrew loosen accidentally. While not specifically claimed to be apochromatic in performance, color fringing in this “TeleXtender" is essentially eliminated.

This image amplifier doubles the power of any eyepiece used with it, while maintaining the comfortable eye relief of longer focal length eyepieces.

Regards.