Interesting that there is no purple "amp glow" in the corner of your image. That problem plaques many cameras.
Good point !
If there is no amp glow in the 50 seconds exposure, then this camera is worth attention.
@ahmad
Nice image.
Did you crop the picture or doing some other type of post-processing?
Can you please make one dng dark frame of 50 seconds and upload it somewhere and post a link here?