The whole optic train now only moves about one pixel of the PL16803 camera (9 micron) over a two hour mount movement even near the SCP where the lateral gravitational forces change at a far faster rate. The 187mm FL Tal finder mounted on the RH200 used as a guider tracks the PMX mount better than one second of arc RMS.
SMC exposures in 3nm NII, 16x16 minutes at -40C. Even with 3nm filters when the Moon is near full gradients get very noticeable with exposures longer than 15 minutes.
Full res image 10MB
http://d1355990.i49.quadrahosting.co.../SMC_NII_T.jpg
Full res inverted image 10MB
http://d1355990.i49.quadrahosting.co...SMC_NII_TI.jpg
This is about as good as I can get the whole system to perform. If the Moon is not present I can do one hour exposures or more. Will do a very deep narrow band of the SMC.
I do have some one hour exposures of the Helix Neb. Still in the process of getting enough darks at -40C.
Bert