The Sword of Orion.

I took this image on three seperate evenings under clear, moonless sky conditions. However I still had inner city lightpollution to contend with; stars visible down to magnitude five. The telescope was my 80mm f/7 refractor with a focal reducer and field flattener making f/6.3. I was also using a Vixen Atlux mount PHD auto-guiding and a set of Astronomik filters. I captured ten minute sub-frames with matching dark frames and combined them with flat field frames to reduce the effect of vignetting in the final image. The total exposure times were 5 hours using a H-alpha filter, one hour using an Olll filter, one hour using an Sll filter and one hour for each RGB filter; making a total exposure time of ten hours.

RGB Colour

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Bi-Colour, H-alpha and Olll

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Narrowband, H-alpha, Sll and Olll

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RGB and Narrowband colour

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Unsharp masked RGB Narrowband

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