Descripción del producto del fabricante:
Please note: This text was taken directly from the manufacturer.
Designed for deep-sky imaging with Schmidt-Cassegrain and refractor telescopes, the Orion Deluxe Off-Axis Guider lets you image and guide simultaneously through a single telescope. This also eliminates tracking problems such as differential flexure and mirror shift that commonly occur when using a separate guide scope. The imaging camera sees the same movement the autoguider sees, resulting in highly accurate tracking for pinpoint stars. Prism tilt adjustment with captive thumbscrew and more than 100 degrees of radial movement allow for easy guide star acquisition. Coarse and helical fine focus adjustments make focusing easy and accurate. The Orion Deluxe Off-Axis Guider can be used with most imaging cameras, including DSLRs, and telescopes with sufficient inward focus travel (requires 59mm). Three different lengths of threaded T-extensions are included (7mm, 17mm, 30mm) to accomodate different camera/guider combinations. Not recommended for use with Newtonian reflectors due to their limited focus travel. One-year warranty.
Comentario de nuestros expertos:
Para garantizar el mismo rango de enfoque en el ocular o cámara guía y la otra cámara, ésta debe fijarse al tubo. Para ello puede ser útil un anillo adaptador Baader Anillo tensor CCD, 1,25".
A veces también es necesario un tubo de extensión como el ["Anillo extensor" http://astroshop.es/es/teleskop-zubehoer/adapter/verlaengerungshuelsen/15_37_10/m,Lumicon].
To ensure that the guide camera/eyepiece and imaging camera are both in focus, it may be necessary to clamp one of them to the eyepiece barrel at a different position. A 'homo focal ring' (Product No. 10610) is useful here.
An extension tube is also sometimes required, e.g. from Lumicon.