Part of the reason for setting up my own website, is to provide useful information for people who are searching the internet. I have been in such a situation on numerous occasions and although I have found very useful information posted, there have been many times where I could not find answers to my questions. Today I will be looking at dew shield for my Astrotech 8″ Ritchey Chretien (AT8RC) telescope.
As I am getting back into astrophotography, I felt I needed to have a dew shield to reduce the effects of dew on my astroimaging, as well as protecting the telescope from stray light coming from the surrounding. As there is no corrector plate to dew up on the Ritchey Chretien telescopes, I am hoping that just having the dew shield will be enough to protect the secondary mirror from dewing up too quickly.
I am aware that Altair Astro does have a model of Kendrick Dew shield which fits the AT8RC, but they have not responded to my enquiries via email so far (and no one picked up their phone when I rang). I also enquired through Tring Astro, who get stock from Altair Astro but I have not had a call back about this either. I did ask them about cutting the Celestron 6″ & 8″ SCT dew shield to fit my Astrotech 8″ RC, and the answer was that it was technically possible. But I might as well buy an outdoor mat and cut it instead (and save cost).
As I could not wait any further, I bought a Celestron 6″ & 8″ SCT Dew shield, as it costs under £30 (the Kendrick one would cover about £50). It arrived over the weekend and I proceeded to cut it to fit my AT8RC. Here are the pictures of this. Unfortunately I did not take a picture before cutting it to fit, but essentially it only had the small notch in the centre – the notches in both corners were cut by me.
So the question I had before was can the Celestron dew shield be made to fit my Astrotech 8″ RC telescope? The answer is yes. But you will need to reseal the edges where it has been cut into, as the stitching has been cut into – to protect that part of the dew shield. It now fits perfectly and is unlikely to fall off. Hopefully this will be sufficient to protect my telescope secondary mirror from dewing up for a few hours (without needing a dew heater), which is likely the length I would do imaging anyway.