M 42 nebula

First session operated through Arduino automatic routine. 

Through a display connected to Arduino, it's possible to monitor acquisition informations and to set up the entire acquisition routine. The status shows if the software is running or not. The LIGHT SPEED indicate the exposure time for every single light frame, and the FLAT SPEED shows the exposure time for the flat frames. The LIGHT SPEED is used to determine the exposure time for the dark frames too. Then we have the counter for every light, dark and flat frames. The DARK LOOP refers to the ratio between the light frame and the dark/flat frame pair. For example, with a DARK LOOP set to 3, every 3 light frames the software will acquire 1 dark and 1 flat frame. The EXPOSURE TIME show the total acquisition time of the light frames. 

The main advantage of this technique is the possibility to take a dark frame immediately after the light frame, by that sampling the temperature behaviour of the acquisition sensor. Other than that, shooting in a quite dusty environment, sampling the flat frame too will help to reduce dust traces. After the light acquisition process is complete, the dark servo motor will drop down a black cap to cover the OTA aperture. The shooting signal is controlled via the external port of the Canon camera, linked to a logic gate controlled by Arduino. The entire system is build to avoid any touch by human hand so the input paramenters are send via an infrared controller.

When the flat cap is called, a led array is turned on to produce the even enlighted surface needed for the capture. Many test has been made to ensure the best possible results. Capacitors for signal stability, thermal noise studying, Arduino signal processing speed and so on. Another important advantage is the possibility to apply this technique to every deep sky target.

The code is writtend for Arduino language, hopefully one day I'll be able to get a dedicated astro camera, nowdays the Canon sensor has made a very good job considering the very light polluted sky of Rome, bortle 8 - 9. By that time I'll be able to reprogram the entire process for python and possibly run the code with Sharpcap. Regarding the data manipulation everything has been resolved with Siril and stars isolated with StarNet. Then I used the raw data with Photoshop to map the colors and add all the channels and informations. The color pallette is red for Ha, blue for OIII and green for SII.