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MX Question
Well, I hope this isn't too obvious, but I can't quite get my head around two things. First, it has been 6 months + since I looked at my polar alignment (I'm permanently set up) and pointing has been a bit off even when I recalibrate into the model. But before getting on with a new model I wanted to check out unguided tracking. With the scope pointing south and not too far from the pole I could do 4 min tacking with no star distortion, But, if I pointed overhead or to the north I cannot do even 1 min without serious trailing in RA. Yes, I get the fact that the velocity of tracking would be slower closer to the pole due to the smaller circumference, and faster progressing away from the pole, but the motor speed is the same in both situations. So, why am I seeing such a huge issue? Would it just be due to PA being off? (Protrack was on.)
Second part....ran a 67 point model and found that both Azi and Alt were off by around 80 arc sec. Is that enough to explain the poor unguided results away from the pole, or is it because the model has only 200 points (I only see about 50% of the sky from my location.)
3rd part. I went to adjust the altitude and tried a method that had worked easily for me 6 months ago, and I totally failed. This feels bad because I've been preaching about how well this "photographic" method works! Anyway, I think I've forgotten what it is I exactly did which is really frustrating. I picked a star on the meridian pointing south. Then I centered it photographically and plate solved the photo. This showed the yellow bullseye in TSX right on the star. I slewed the mount down 80 arc sec, so the yellow bullseye moved off the star 80 arc sec down. After that I went out and adjusted the mount up 1 tic and took another photo, plate solved it, but the bullseye did not move at all. I expected to see it move after the plate solve but obviously something is messed up in my reasoning. Anyway, there has got to be an easier way to do this. Perhaps I should put the camera in focus mode with a smaller frame? But, I'm still trying to figure out how to measure the movement the exact distance. A crosshair showing the center of the photo would certainly help. Any ideas? I can use CCDSoft or the TSX camera add on. THANKS!!
Peter
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