My first HaRGB result!
And a new personal record for total exposure time: 6 hours in 72 subexposures.
And the first time I combined exposures from two nights. The first night I took H-alpha exposures and the other night I took RGB exposures, both with the EOS20D and the Takumar 135mm. I used my 550mm refractor with the DSI camera as guiding scope for the first time. This worked very well.
Here is the resulting image and more info: http://www.astro.pwng.nl/item/north-america-nebula-in-hargb
A new guiding scope
Today I tested my new guiding scope. I moved my DSI guiding camera to my Meade ETX105 and I use this combination as a guide scope. The focal ratio of the Meade ETX is f/14: far to high to guarantee the capture of a guiding star during a 3-5sec exposure in the small field of my DSI camera. Therefore I added a home-made focal reducer for this combination. The focal reducer is made from the objective lense plus tube of a 6x25mm finder scope. The focal distance of my ETX 105 is now reduced from 1470mm to about 450mm. More stars visible in the field of my guiding scope and a nice focal distance for guiding of my 550mm main scope.
This guiding scope is more heavy than my previous guiding "scope", at 70-200mm zoom lense. So there is the risk of too high load of the mount resulting in vibrations during long exposures.
All went fine. The weight is OK, I managed to shoot 20 lights with 5min exposure time without any star drift.
Here is the result: http://www.astro.pwng.nl/item/andromeda-nebula-2