A:AnswerI am also getting back into astronomy in particularly Astrophotography. I've done a lot of research on cameras and like you, would like to have one that is good for both AP as well as every day use. I currently have a Sony NEX. 5N. While that is a great camera it is not full frame, which is what I'd like to use for AP. I also have a number of Sony lenses, which means a signiicant expense in th purchase of new Canon lenses. However after doing the research, I've decided the Canon 6D is the one I'm going to purchase. On the positive side, it one of the best, if not the best cameras for low light photography with respect to noise levels. The price of the camera is very reasonable for a full frame camera. The reviews both for AP as well as normal daylight photography are exceptional. In general, versus other cameras, particularly the Sony but less so for the Nikon, there is far more AP software available for Canons. On the minus side, the camera has been around for some time and will probably be replaced by a new model with updated features either late this year or in 2017. Autofocus is substandard to most other cameras on the market at this price point. However for AP, you'd be using manual focus anyway, and for normal photography, it would probably only limit you to photographing action sports. Two things I love about my Sony that will be missing from this camera are an articulating LCD screen that is also a touch screen. The LCD is fixed on the 6D, making it difficult to use with a refracting telescope, which is certainly a disadvantage. The touch screen is simply a nice to have. There are however, a couple of things the 6D has that the Sony doesn't. It has GPS and is WiFi enabled. The GPS is a huge advantage at least for me. If you have your eyes set on photographing nebula, there is a distinct advantage of working with an H-alpha modified camera to capture the reds in the nebula. If you modify a camera, it is no longer usable for normal photography. I've thought about waiting for the new model because it may have improved autofocus and articulating LCD screen. Then I think about the possibility of something happening to the low light sensitivity in the new model versus what's currently offered. I also think about how much more expensive the new model will be, especially out of the gate. So based on the strengths I listed above with the added features of GPS and WiFi, I'm going to make the move and purchase this camera and be judicious with the lenses I purchase. I hope this is helpful. As I said, I'm no expert and may have some things not exactly right, but felt I should pass along what I've learned if it helps someone else make a decision.
A:AnswerIf you upgrade to a Canon full frame camera any Canon "EF" lenses will be compatible. However, you can not use Canon EF-S lenses with a Canon full frame camera. I know that the Canon EF 50mm f/1.8 will work, but I'm not familiar with the 85mm f/1.8 lenses. If it's an EF series lenses it will work on a Canon full frame. Hope this helps.