Backfocus question for STXL 16200

Discussion in 'STX and STXL' started by Mark McComiskey, May 16, 2019.

  1. Mark McComiskey

    Mark McComiskey Standard User

    May 16, 2019
    I have a Takahashi TOA-150B with a TOA 35RD reducer, the backfocus is 62.5mm

    I would like to get the SBIG STXL 16200 and use the FW8G filter wheel. SBIG lists the backfocus for the STXL 16200 + the FW8G filter wheel as 60.6. With 3mm filters, that becomes 59.6mm

    I suspect that even a custom adapter to mate the SBIG equipment to the Tak reducer will be more than 2.9mm?

    Do I have the figures correct here? Is there any solution? I had read on a forum elsewhere that custom faceplates might save a few mm?

    Thanks for any help.
  2. Doug

    Doug Staff Member

    Sep 25, 2014
    Yes it may be possible to do a custom adapter. For example, we have camera lens adapters that protrude a little into the front of the filter wheel. Look at the front of the wheel in the photo below - as long as you don't touch the pick-off mirror assembly you can protrude into the wheel a fair distance. The wall thickness is IIRC 3.8 mm.


    The other alternative is to use the FW8S wheel and add a piggyback guider, such as the remote head + guider kit.

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