SX CCD light path setting

 - CCD ~ flange : about 17mm (+- 1mm by flange setting, CCD alignment screws are provided for setting the chip parallel to the focal plane)

 - SX Filterwheel : 29mm

 - SX Filterwheel + SX OAG : 42mm

 * CCD+SX FW+Astrodon GEN2 LRGB  : 45mm  (17+29-1)

 * CCD+SX FW+SX OAG+Astrodon GEN2 LRGB  : 58mm (17+42-1)

BF adjustment with filters

Adapter Setting

 1) For TAK e180ed (backfocus : 56mm)  

     * CCD+SX FW+Astrodon GEN2 LRGB : 56 - 45 = 11mm

     * CCD+SX FW+SX OAG+Astrodon GEN2 LRGB : 56 - 58 = -2 Need to reduce 2mm

 2) For 3inch ADT Corrector (backfocus : 65.8mm)

     * CCD+SX FW+Astrodon GEN2 LRGB : 65.8 - 45 = 20.8mm

     * CCD+SX FW+SX OAG+Astrodon GEN2 LRGB : 65.8 - 56  = 9.8mm