William Optics Apochromatic refractor AP 71/350 Triplet Star 71

Item description:

Optimized for astrophotography, this apochromatic refractor consists of four elements in three groups : 2-1-1 configuration. This unique design made of FPL-53 (Ohara) fluorite glass illuminates 45mm diagonal sensors with pure color with point-shaped star images - ideal for full-frame cameras!

The 2.5" focuser with 1:10 reduction and 35 millimeters of focusing travel has an M48 thread. This offers numerous connection options for cameras. For example, a single-lens reflex camera (DSLR) can be connected directly using a bayonet adapter with M48 thread Since the correction optics are already integrated into the Star 71 optical system, there are no problems with the optical path lengths that are otherwise encountered when using an external flattener.

The Apochromat Star 71 is ideal for photographing large areas of nebulae , such as the Rosette Nebula or Lagoon Nebula (M8), as well as for large galaxies such as Andromeda (M31) or Triangle Galaxy (M33).

The Star 71 was designed for photography. Therefore, it does not come with a star diagonal either. It is also not possible to connect a normal 2" star diagonal, since the Star 71's back focus is not sufficient. However, so that the Star 71 can still be used visually, William Optics has developed a special star diagonal, on which the usual 1.25" -Eyepieces can be plugged in. You can find the mirror under "Recommended Accessories".