It still is dewing up. Shows up as cold pixels. I discovered an option in Deep Sky Stacker to remove cold pixels and replace with median.
Anyway I should be collecting my two large bags of molecular desiccant from Sigma-Aldrich tomorrow or next week. That should be good enough for several years.
I had to extend the tube of the AT8IN so that the focuser doesn't need to be racked out so much:
So now, no more need for an extension tube or the Feathertouch focuser base extension. I may put the base extension back in so that the drawtube isn't extended so much..
Before I lengthened the tube, the focuser stack looked like this (very ungainly):
Thing is, the AT8IN (and 6- 10- and 12-inch versions) seem to have been designed for a DSLR without any coma corrector. So with a CCD and Paracorr, an extension tube is required and the focuser has to be racked out a lot. This causes instability. So my mod improves stability, but makes the scope incompatible with a bare DSLR (it still reaches focus with a DSLR and Paracorr).
Something to keep in mind if you're planning on getting one of these imaging newtonians and will use it with a CCD.