[Dennis]

Hi

Here is a “quick and dirty” image of M16, my first light with the ST7E and C9.25. Being experienced with using the ST7E with my Vixen 4” refractor at only 918mm focal length, I was more prepared for imaging at the longer focal length of 2350mm for the C9.25, which is much more demanding as I discovered.

The M16 image is a stack of 3 exposures of 3 mins each; auto guided using the ST7E although it suffers from the effects of imaging through thin, high cloud over Brisbane when I captured the individual exposures.

I also discovered that during auto guiding, I had a periodic oscillation in RA with the Takahashi EM200, which was slightly disappointing given the pedigree of Tak mounts. The RA corrections kept oscillating between ±1.5 units when I was expecting ± 0.5. I had to discard several images due to elongated stars. I am still investigating this oscillation to see if I can null it out.

Cheers

Dennis