This four-lens Barlow is a telecentric system and offers outstanding imaging performance, even off the optical axis. This distinguishes them from conventional constructions, where the image becomes noticeably worse towards the edge. This is a major disadvantage especially for flat objects such as the sun and moon. The Barlow lens not only has a high-quality look, but also an exemplary interior blackening. This is very important, otherwise internal reflections would worsen the contrast. Of course, the lens edges are also. This Barlow lens does not produce any additional color errors and is therefore ideal for apochromatic lens telescopes.
The Barlow extends the focal length of the telescope by the specified factor, and the focus moves further back. A special feature of telecentric barlows is the parallel light emission, the distance Barlow / camera no longer changes the extension factor, this is advantageous if additional accessories such as a filter wheel are to be installed in front of the camera.
The field of view is better corrected than in case of Barlow lenses, meaning that the image won't get distorted around the edges.
The 2x, 3x model is ideal for telescopes with longer focal lengths, while 5x version is for the faster telescopes. The TeleXtenders are ideal to use on Moon, planets and double stars (of course deepsky objects as well) both visually and photographically.
|Extension of focal length||3|
|Connection (to the telescope)||1,25"|
|Connector (at camera end)||1,25"|
|Number of lenses||4|
|Type of build||tele-extender|