The Celestron 8” SCT telescope is an excellent set of optics. With all telescopes and especially at 8” the main corrector plate is prone to dew formation during imaging especially in the Spring or Autumn months here in the UK
If the corrector plate mists over with dew during an astrophotography session the images being taken will fail. At no point attempt to wipe the corrector plate – this must not be touched as damage may occur leading to poor optics going forward. The only thing you can do is place the telescope inside and let the dew naturally dry off.
To combat this event and prevent the dew formation a dew shield is placed on the end of the telescope and a heated dew strap is placed around the shield just beyond the corrector plate. I have found this shield beneficial in two areas:-
- Prevention of dew formation on the corrector plate
- Block stray light from nearby streetlights entering the scope.
Connections to power units discussed in later blogs.