> Pentax Astrotracer
Astrotracer is a great way to take advantage of the Pentax DSLR camera in-body shake reduction mechanism. It is available since Pentax k5 and track celestial bodies by moving the sensor. Here is what is it ablout:
It is most suitable for low power panoramic astrophotography with focal lengths from 35mm to 135mm. Thus could be used with longer telephoto lens but it's calibration is a real challenge and it is hard to achieve good tracking result. For wide angle shots this tracking is boosting comma and distortion effects as sensor is going beyond the calculated filed of for the specific lens. Also it is mostly suitable for single shots. After the shot is taken, the sensor is getting back to it's original position and if you need to do a series of shots you need to readjust the camera position. The main advantage of this technology is that very compact and you could have it always with you. Sometimes the best shots are those we do not plan. Here are my examples:
Below is a shot with a 500mm lens:
For a few months from now Betelgeuse (Alpha Orion) dim so much, that it looks as bright as the stars in the Orion belt. This is not so disturbing and does not mean that cataclysmic events are happening with it.
For my last trip to the Rodopa mountain I decided to cross the limits and to target an object that is hard to believe that a non-professional equipment could catch.
While cleaning up my PC I found sequences of shots of Virgo galaxy cluster taken during springs of the last 2 years. Those were attempts to shot this object, but I was not satisfied with the result and left them.
I recently bought a pocket spectroscope for laboratory use. You can find it at Ali for 5$. It is with glass prism and well build. So I did some test to use with a telescope but did not
http://www.deepskywatch.com/deep-sky-hunter-atlas.html This is an amazing resource. Detailed atlas of all the sky with NGC and IC objects.