Astrograph 160mm D-ERF Custom Cell to fit 186mm Dew Shield

This is a custom made cell to take a Baader 160mm D-ERF Energy Rejection Filter. It is made to fit dew shields with a 186mm diameter. Typically this means it will fit all OTA's produced by United Optics for 150 / 152mm Optics.

By acting as both an aperture stop and ERF, the cell permits a wider range of scopes to be converted for use with rear mounted H-Alpha filters for solar observing and imaging.

When fitted the 160mm D-ERF provides an aperture of 155mm. When fitted to the following OTA's the focal ratio will change as follows;

APM Telescopes 152mm F7.9 Doublet Apochromat. Standard focal ratio remains F7.8 (with Baader TZ-4 this is F31.6)

​Tecnosky 152mm F7.9 Triplet Apochromat. (also TS-Optics 152mm ED Triplet and 150mm Doublet, Altair Wave 152mm ED Triplet and 150mm EDF Doublet). Standard focal ratio remains F7.8 (with Baader TZ-4 this is F31.6)

APM-LZOS 152mm F7.9 Triplet Apochromat (Aluminium Tube). Standard focal ratio remains F7.8 (with Baader TZ-4 this is F31.6)