Yes, a 13nm bandpass will allow shorter subs. Lets in more energy so it should! Depends on what your objectives are with Ha imaging. The results from a 4nm filter are very different to that of a 10nm for example. Only need to see the work of Gleason to draw this conclusion. He did a great presentation at last years AIC that can be viewed
here (10.5Mb pdf). Provided a educational experience to see what people are now doing with Ha filters. huh? 5x40min subs with a 16803 and 6nm filter...ah, that was so yesterday...perhaps I should quote from the slide deck;
"• 30 minute to 60 minute sub-exposures are now normal for narrow band imaging. This leads to multiple hour, multi-night imaging. (4 to 20 hours total exposure time is typical)". Of course, I'm happy with 10min subs too.
Enjoy!
You know what's ironic Mike? Your 3x30 min subs, each with different anomalies would vanish with data rejection removing the outlier pixels on each frame. Thus leaving you with a killer rich Ha master to work with. Food for thought my friend. Nice images btw.
