Another clear windless night last night prompted me to head out to my observatory at around midnight to do some more Ha imaging.
I particulary wanted to shoot M16 but I also decided to see what M20 would look like ... not normally a hydrogen alpha target ... as you would expect you only get half the object ... the emission ( red ) nebula ... the reflection ( blue ) nebula is disgarded by the Ha filter.
There was a fair bit of Ha in close proximity to M20 that was captured by the 7nm Baader filter... I'm not sure you will be able to see it very well in this web sized image as jpeg compresion tends to wipe it ... it was quite pronounced in PS when processing.
Anyway here are the images.
M16 1 hour 6 minutes total @-18C
M20 55 minutes 4 seconds @-15C
p.s. I reserve the right to repro these images at a later date