APO 2x extender

The 2x APO extender is inserted between the telescope and the camera, allowing you to double the focal length of the instrument. Using this accessory the image is 2x magnified: for example, using a telescope with 600mm focal length, the focal length becomes 1200mm. This instrument is therefore essential to increase the magnification without losing too much brightness for bright astronomical subjects as the Moon or the Sun (warning: photograph and observe the Sun only by proper filters) or terrestrial subjects, for example in nature photography.

Thanks to the special construction with 3 optical lenses, this 2x APO extender keeps the contrast and the original image definition without introducing aberrations or spurious colors.

A DSLR camera connected to AIRY ED100 telescope using the 2x APO extender.

The 2x APO extender has in front (telescope side) a female T2 thread, in rear (camera side) a male T2 thread. In order to connect to telescope, you simply need to add a normal T2 adapter. In order to connect cameras to it, you neew a T2 ring if you use a DSLR camera or you can directly connect a CCD camera if it has in front a T2 female thread.

Note: the requested backfocus distance for this extender is 55mm. For DSLR cameras, this distance is normally achieved by positioning (between the extender and the camera body) a normal T2 ring (for example Canon EOS DSLR sensor is normally placed at 44mm from the front bayonet and the T2 ring is usually 11mm thick). The CCD cameras instead have the sensor placed forward so, if you want to connect them directly to this extender, it will require a T2 extension. For example, since the CCD ATIK 428EX or 460EX have a back focus (distance between the sensor and T2 front thread) of 13mm, you'll need a 42mm T2 extension (55mm - 13mm) to bring the sensor to the proper working distance from the field flattener.