Tuesday, February 25, 2014

Hydrogen Alpha vs Red

Hi all
Well after a long break I have got back into astrophotography. To celebrate, I purchased a second hand QSI 583wsg camera with a full set of Astrodon RGB and Narrowband filters.

I have only ever used one shot colour cameras in the past. Either an Canon 40D or the QHY8 cooled camera. The QSI is my first mono camera.

I have only spent a couple of nights using the camera but what amazed me about using the Ha filter is that even though the Hydrogen Alpha filter captures a much narrower portion of the red band (hence the narrowband name), for the same amount of time it revealed much more nebula data.  Below are two images; both are a single 5 minute exposure on the same night The first is with the Astrodon red filter, the same is with the Astrodon 6mm Ha filter.  Although the HA reveals less stars it shows a lot more of the nebula.

I have also included a spectrum from the Astrodon Site to show where the H-Alpha filter sits compared to the Imaging Red filter.