Entry level equatorial mounts don’t tack accurately for longer than 60 seconds. It gets even harder to track precisely with longer focal lengths. Guiding is the answer and my next major goal in improving the astrophotography setup. By guiding, you can keep exposing for much longer times (5-15min and even beyond). That will allow you […]
Stacking images to increase SNR (signal to noise ratio) is a fundamental task of astrophotography. Aside from the light frames, which are the actual image data, there are also 4 types of calibration frames: Bias, Darks, Flats and Dark Flats. In order to remove vignetting and any uneven field illumination caused by dust or smudges found […]
Comparing this image with the one shot using the ST-80 achromat, the difference is definitely noticeable. The edges of the moon are free of any purple fringe. Also the moon is sharper and obviously a bit closer due to the 600mm focal length of the ED80.
At this point, the main problem in my images that really annoys me is the chromatic aberration (the purple fringe around stars). Also the field curvature of the ST80 is really bad, especially on a crop size sensor, as you begin to move away from the center of the frame. So to achieve a considerable […]