Saturday, 6 January 2018

Histograms, AstroDMx Capture for Linux and The Orion Nebula

A ZWO ASI120MC camera was placed at the Newtonian focus of an f/5, Skywatcher Explorer 130 P-DS OTA Newtonian mounted on a Celestron AVX, EQ, GOTO mount. 100 x 15s exposures of the Orion nebula were captured with AstroDMx Capture Linux running on a Fedora laptop. 25 matching dark frames were also captured.

The imaging setup


The images were registered, stacked and dark frame corrected in lxnstack, a native Linux application. The final image was processed in the Gimp 2.9.
Nicola has now implemented histograms in the software, some of which can be seen in the live preview screenshots below.
Screenshot showing a linear, averaged RGB histogram


Screenshot showing a logarithmic, averaged RGB histogram


The histograms can also show computed luminance, R, G and B channels as well as the RGB channels together.
Final image of M42/43


Box-mounted Raspberry Pi camera module, a Skymax 127 and Tycho

A Waveshare 5Mp Raspberry Pi camera module with a OV5647 CMOS sensor was mounted in a project box and a connector was used to connect the short ribbon cable from the camera, to a 1m ribbon cable from the Raspberry Pi 3 running Ubunto MATE Linux.

Box-mounter PiCamera


The camera was placed at the prime focus of a Skymax 127 Maksutov mounted on an EQ mount.

Using Python 3 software that I have written to capture .bmp images, I captured 100 .bmp images at 1024 x 768 resolution, of the Tycho region of the Moon. The images were registered and stacked in the Linux application lxnstack. The resulting image was wavelet processed in Registax 6 running in Wine via Exagear, and post processed in the Gimp, all on the Raspberry Pi. The wavelet processing was the only part of the process that ran slowly.

The Tycho region