Hi All. Had another go at Jupiter last night. Have reset up my conservatory as a warm room now I have a longer cable for the motor focuser. Air was pretty steady but transparency was not so great.
Also I focused on a bright near by star using a Bahtinov mask first. The attached photo is a stack of 172 frames out of 1700. I decided that I was setting the quality levels too low before. There is some nice detail here. Taken using the C925 Optic Star PL-131C webcam (at 1280x1024 pixels) and x2 Barlow. I was so happy with what I was seeing I thought I would try pushing the magnification. When you start to use more powerful Barlow like x3 and x4 (what I was hoping to use last night) you need to refocus but finding Jupiter again and getting it centred on the chip wasn't easy so I came up with a little trick. It may sound complicated and long winded but believe me it is taking far longer typing it out than it does to do.
Right with your x2 Barlow still in place slew scope back to nearby bright star and centre. Take out x2 and put in x3. Focus and recenter. Take out x3 and put in x4 focus and recenter. You webcam is now in focus with a x4 Barlow. Take out x4 put in x2 and slew to Jupiter. You will have a very large bright ring (turn up the brightness first in your webcam control software) and recenter. DO NOT touch the focus. Take out x2 and put in x3 and recenter, Jupiter will still be a large bright ring. Take out x3 and put in x4 and recenter. You will now have a centred and focused Jupiter just adjust your webcams exposure settings and start imaging.
Like I said it is far quicker to do than it was to type this.
Anyway, that's what I did last because I was impressed with the quality I could see while webcam imaging with the x2 Barlow. Only problem is after about 100 frames of Jupiter with the x4 Barlow in place Jupiter went out like a light bulb being switched off! Oh Nooooo! What's gone wrong??? Has my dew shield slipped and is covering the front of the scope? No!!! Has a cable been pulled out or has the mount slipped? No!!!
BLOODY CLOUDS!!!! The rotten SODS!!! Just when I had everything perfect for a good high mag imaging run!!!!
Anyway hope you all like it.
Celestron C925, NEQ6, Optic Star PL-131C with Tele Vue x2 Barlow
172 frames of 1700 SharpCap, Registax and tweaking in CS4