Last year I experimented briefly with the O-III narrowband filter. The plan was to boost the number of nights in the year that are available for doing photography by imaging on moonlit nights. By exploiting the high sensitivity of the unmodified camera to Oxygen III (blue-green) emissions maybe I could get some decent closeups of some strong O-III emitters.
I hadn't had a chance to take a long set of guided exposures until last night. With the old moon blazing away, lighting up some thin, high cirrus, I had a play with the camera, and I was chuffed with the result
- This was under a 90% moon ! I've got to try some more of this... Wish I had a modded camera
to combine it with some H-alpha... The Tarantula just belches oxygen, which explains why it looks so blue in my unfiltered shots.
SN-8 LXD-75 with Astronomik O-III filter
33x2mins ISO1600
Canon (unmodified)