Hi all
My Baader "Narrowband O III" 2 inch filter arrived today and when skies briefly cleared I whacked it into the 10 inch scope to try on Eta Carina. The finished image was green, but also had some blue in it. There was no nebulosity in the red channel. So I removed the red and reduced the blue by 50% as there was some nebulosity in the blue, lots more in the green. I then turned it to greyscale.
2x 10 mins iso 400, modded 350d, 10 inch f5.6, some cloud and haze present.
Scott
nice. I've just got an OIII filter myself but have no clear skies-the Bintel moving sale was too good an opportunity to pass up...The Helix is another O III worthy object..I plan to give it a try with an unmodded canon and an OIII filter..didnt realise Eta was also amenable to OIII..got to add that to my list
Thanks.
Yes I think greyscale is the best format for a single colour image.
Gee the filter is dark. I guess I should do some visual observing with it too. Unlike the H alpha filter I can at least see nebulosity in the viewfilder, but focussing requires moving the scope to one of the stars in the southern cross as none in Eta Carina are bright enough. I might see if I can do some "mapped colour" images by combining this green O3 image with a H alpha image.
Scott
Narrowband sure raises the signal to noise. Excellent result. What is the bandwidth of the filter? For F2.8 about 10nm is needed due to greater angular variation of incoming light. Otherwise transmission suffers.
Heres a sort of mapped colour version, where I took a colour image shot through my UHC-S filter, but then replaced the green channel with the O3 shot. I had to crop it as the orientation of the 2 shots was way different.
Scott
