Originally posted by MossyRocks Apparently today was my lucky day and I found the SMC A* 400mm f/2.8 I've been trying to find for a while now. It should arrive next but apart from having a big heavy tripod and head capable of holding (I have both already) it what should I know about using this lens well? My main plan for it is to point it up into the night sky and chase the larger deep sky objects and suck in those elusive photons but what should I know for using it in other situations. Finding information on this rather elusive lens is hard so pretend I know next to nothing other than this thing exists. I also don't know anything about the rear drop in filter system which is what I have the most curiosity about so that would be helpful so I don't screw things up as I will be using a filter at night when shooting astro shots.
The filter cell is a frame with a M49 thread for a conventional filter. You just have to unlock the bolt, pull the cell, thread a filter in, re-insert the cell and lock it.
Look in the lens review section for information about the lens.
Good luck, it should perform well for astrophotography.