coldlegs
30-05-2015, 04:31 PM
When the clouds part and the moons not too annoying I've got this itch to rush out and go for it! But sometimes you need to slow down a little.
After giving up trying to make my “pseudo” serrurier truss scope into a “true” serrurier scope and discovering complicated balance issues with an offset camera arrangement I went back to a very rigid truss set up. At the same time I fixed a bunch of faults and annoyances. Moved the secondary spider closer to the front, increased the secondary to 2.5”, aluminium brazed most of the front cage for stiffness, added new flocking plates to the front cage, machined a new carbon fibre plate for the focuser to align properly with the secondary, added two baffles, one in front of the centre support and one in front of the focuser, moved a small fan to the front face of the main mirror for thermals and added springs to the two focuser motors so I could easily adjust the focuser tilt.
And the clouds parted. Rushed out, aligned the scope, focused it, focused the guide scope, raced over to M83, zoomed in and forgot to do the tilt!!! My wonky eyes see small ovals as small circles and vice versa so close in M83 close in looked great but had I looked at the bottom left corner even I would have seen a ten percent tilt! Saw it the next day when processing the lum but decided to leave and see if I could get some colour then fix it. Eleven days later they just parted just long enough to get some colour. This LRGB business really sucks up the hours. Managed to get a reasonable image but clipped the black a little too much but that will have to do for 2015.
Must try harder next year.
Cheers
Stephen
Large here (about a 50 percent crop)
http://www.astrobin.com/183528/ (5Mb)
Scope Newt truss 10”/F5
Camera QHY9M
Filters Astromic LRGB
ONAG
Guider Loadstar
Lum 50x300sec 1x1 -40C
Red 15x300sec 2x2 -40C
Green 15x300sec 2x2 -40C
Blue 15x300sec 2x2 -40C
Flats/Bias 15 -40C
After giving up trying to make my “pseudo” serrurier truss scope into a “true” serrurier scope and discovering complicated balance issues with an offset camera arrangement I went back to a very rigid truss set up. At the same time I fixed a bunch of faults and annoyances. Moved the secondary spider closer to the front, increased the secondary to 2.5”, aluminium brazed most of the front cage for stiffness, added new flocking plates to the front cage, machined a new carbon fibre plate for the focuser to align properly with the secondary, added two baffles, one in front of the centre support and one in front of the focuser, moved a small fan to the front face of the main mirror for thermals and added springs to the two focuser motors so I could easily adjust the focuser tilt.
And the clouds parted. Rushed out, aligned the scope, focused it, focused the guide scope, raced over to M83, zoomed in and forgot to do the tilt!!! My wonky eyes see small ovals as small circles and vice versa so close in M83 close in looked great but had I looked at the bottom left corner even I would have seen a ten percent tilt! Saw it the next day when processing the lum but decided to leave and see if I could get some colour then fix it. Eleven days later they just parted just long enough to get some colour. This LRGB business really sucks up the hours. Managed to get a reasonable image but clipped the black a little too much but that will have to do for 2015.
Must try harder next year.
Cheers
Stephen
Large here (about a 50 percent crop)
http://www.astrobin.com/183528/ (5Mb)
Scope Newt truss 10”/F5
Camera QHY9M
Filters Astromic LRGB
ONAG
Guider Loadstar
Lum 50x300sec 1x1 -40C
Red 15x300sec 2x2 -40C
Green 15x300sec 2x2 -40C
Blue 15x300sec 2x2 -40C
Flats/Bias 15 -40C