M42 Color Image



This is my first attempt at using a CCD camera to produce a color image. The telescope used a Takahashi FC100 (4" refractor) using an f/6 field flattener. The telescope was mounted on a GM11 mount. The camera used was an SBIG ST7.

Six exposures were made. Two 400 second exposures were made through a #25 Red filter. Two 800 second exposures were made through a #58 Green filter. Two 1200 second exposures were made through a #38A Blue filter. In addition, a IR block filter was used for each exposure. I had to remove the camera from the telescope to change filters. Because the filters are not parafocal, I had to re-focus for each exposure set.

The six images were calibrated and registered using Mira Pro. Each of three pairs of images were then median combined to eliminate residual noise. The three resulting images were placed in TIF files and transferred to Photoshop 3.0. The TIF files were combined to make two color images. One image was gamma adjusted to show the detail of the Trapizium area. The other image was gamma adjusted to show the detail in the outer dust clouds. These two images were then combined to create the above, final image.

The green cast was unexpected and is probably due to some error in my process.



Back to the observatory.