Eta Carina in 7 Nm Hydrogen Alpha under a full moon
Hi
With the full moon up and a sky so bright I used the Baader 7 Nm Ha filter on Eta Carina nebula.
4x10 mins ISO400 Baader 7 Nm Ha filter, Idas uv/ir filter, MPCC coma corrector, 10 inch f5.6 newtonian, Modded 350D camera, hand off axis guided. Total 40 mins exposure time.
Sky was so bright I could not see Eta Carina naked eye at all, it was faster to use the Argo Navis to find it. The night was warm and there was a heap of dark current noise in the images, I took 3 darks afterwards and in Iris made a master dark, subtracting that in Iris from the light images got rid of most of the noise. A flat and offsets were also done as usual.
Thanks.
When I saw the deep red nebulosity everywhere on the original images on the camera screen I was amazed how well the Ha filter works, it cuts through light pollution
Thanks all
Good question, Gama and its because the narrowband filter doesn let in infra red light lower down in the spectrum, they recommend a uv/ir filter for full cut off, only allowing in the Ha light. My DSLR is modified to allow in all light as I chose the clear glass option on the sensor when I ordered it from Hutech so I can do dinfra red imaging if needed.
Heres a colour version, showing similar to what it looks like on the camera screen
Scott
Thanks
No thats the FOV, well was very slightly cropped as I move the telescope very slightly between each image to help smooth out non random noise. Probably about a dozen pixels shaved off one side.
Scott
Thanks all
I didnt think I was going to be doing anything as in the afternoon high cloud from the anvils of storms out west came over but dissipated once it got dark, look slike same is happening today. Might do some more Ha imaging tonight if i can
Sometimes the guiding doesnt wanna behave but last night it went well
Scott
Very nice detail, great image. Reminds me of looking down that jagged edge of constrast visible, in a 16" dob a while back with a nagler ... such nice detail and contrast.
Thanks all
Good question, Gama and its because the narrowband filter doesn let in infra red light lower down in the spectrum, they recommend a uv/ir filter for full cut off, only allowing in the Ha light. My DSLR is modified to allow in all light as I chose the clear glass option on the sensor when I ordered it from Hutech so I can do dinfra red imaging if needed.
Heres a colour version, showing similar to what it looks like on the camera screen
Scott
I had a look at the spetral response for this Baader filter, and it has IR cutoff up to 1180nm. Thats quite high. You wont get any IR higher from this as the sensor isnt sensitive to this spectrum area. So you wouldnt need it.
Unless my data on the Cmos sensor spectrum bandwidth is up the kaboo.