Hi
With the sky suddenly clearing I had to get out and take a picture of something. I went for the Rosette Nebula under a full moon, with the Ha filter
6x3 mins and 2x10 mins ISO1600 6 inch F3.6 SN "Cometracker" Baader MPCC and 7Nm Ha filter, Modded 350D camera, shot from inside the garage through the open door. Hand guided. Green and blue channels discarded, only red channel used.
Scott
Very nice image Scott.
Great wide field and sharp with plenty of dark lanes.
This is one target I would love to try when I re-configure for the 400mm
It will be difficult to out do your efforts 'though.
Good work, you do the hand guiding so well.
Its interesting to see that the Ha filter works so well with a dslr
also the image scale fits .... framed perfectly.
Might i ask why the different time settings ie 3 mins and 10 mins
Thanks all.
Jeff, I uswed only the red channel as when I first started using the Ha filter, I loked at the other 2 channels and noted they only contain stars and thermal noise/amp glow, no nebusosity (except in very bright ones like M42 where excess light leakes over into the green and blue pixels). Im thinking if I reject those 2 channels I will be keeping only about 1/3 of the thermal noise.
Heres an original (10 mins ISO1600) both full and cropped. The noise is incredible, a cooled DSLR would be better, its incredible how much dark subtraction can remove most of the thermal noise too.
Heres just the green and blue channels, theres no nebulosity, just thermal noise and some amp glow.
Scott
Good work, you do the hand guiding so well.
Its interesting to see that the Ha filter works so well with a dslr
also the image scale fits .... framed perfectly.
Might i ask why the different time settings ie 3 mins and 10 mins
Thanks
I started out doing 3 min shots to see how the guiding went, but as things were going so well, and the Ha filter cuts out the moonlight so well, I thought Id increase to 10 mins, then added them all together with Iris.
Scott
Nice detail there Scott. Gotta love Ha imaging (or for that matter any narrowband imaging) when the moon is up. Data looks a little noisy, but feel certain more exposure will resolve this. Looking forward to seeing if you'll combine it with some chrominance data.