LewisM
04-12-2013, 08:56 PM
I made a start on a target I have waited a while for - NGC1566 in Dorado.
Lum and H-a were around 45 minutes total each - this was when the scope was on the west side (weights on the east) - giving perfect tracking - did not have to touch anything for the entire H-a and Lum run. Then after pier flip, all hell broke loose, and I did remember to decrease the counter-balance weight just slightly and add the small weight to the east side of the dew shield. RGB was awful - either bad tracking (PHD would keep the star centroid centred for only 15 minutes), or the seeing degenerated in fluctuations, rendering some subs great, others a noisey morass! (with the SBIG sitting happily at -25°). Ended up with a mere 4 x 5 minute subs for each RGB filter, and even some of those are cruddy.
BUT, I have made the best of what I have so far. I will continue with this target (with which telescope at this stage undecided), adding more Lum and MUCH more RGB. I blended the H-a in ala Robert Gendler's technique but there is not much there - a few splotches of red nebulosity in the arms, but not much in this limited exposure range. The very distant background galaxy is barely discernible at this stage, and those ruddy stars are too big so far. Dawn was cracking when I was just finishing the crappy RGB, hence the blue gradient. It's got a LONG way to go!
And baking the SBIG desiccant plug worked a treat - not even the remotest sign of ANY frost even "shocking" the system from +24° to -25° in a matter of minutes - LOVE that camera!
Lum and H-a were around 45 minutes total each - this was when the scope was on the west side (weights on the east) - giving perfect tracking - did not have to touch anything for the entire H-a and Lum run. Then after pier flip, all hell broke loose, and I did remember to decrease the counter-balance weight just slightly and add the small weight to the east side of the dew shield. RGB was awful - either bad tracking (PHD would keep the star centroid centred for only 15 minutes), or the seeing degenerated in fluctuations, rendering some subs great, others a noisey morass! (with the SBIG sitting happily at -25°). Ended up with a mere 4 x 5 minute subs for each RGB filter, and even some of those are cruddy.
BUT, I have made the best of what I have so far. I will continue with this target (with which telescope at this stage undecided), adding more Lum and MUCH more RGB. I blended the H-a in ala Robert Gendler's technique but there is not much there - a few splotches of red nebulosity in the arms, but not much in this limited exposure range. The very distant background galaxy is barely discernible at this stage, and those ruddy stars are too big so far. Dawn was cracking when I was just finishing the crappy RGB, hence the blue gradient. It's got a LONG way to go!
And baking the SBIG desiccant plug worked a treat - not even the remotest sign of ANY frost even "shocking" the system from +24° to -25° in a matter of minutes - LOVE that camera!