M42 on the 04th Feb 2007. Almost a full moon up but the IDAS LPS-P1 filter did a good job (though it’s not narrowband). Pity that guiding was a bit off (you can see ghosts of the stars from the pendulum effect of the autoguiding). Must work on that.

Sac10 + Celestron f6.3 FR + IDAS LPS-P1 + Megrez 90FD APO

4×180 sec + 1×240
10x10sec for Trapezium.

All processing in Photoshop

Here’s another version using a synthetic ha filter