The Minolta Roxxor X 50mm f/1.4 I'm on day 8 with my Sony NEX-C3 kit. I'm currently working to expand the accessories & so forth. I've added a generic spare battery & charger, UV and polarizer filters. I added a Nikon "G" adapter for my old manual focus (1980?) Nikon Nikkor 50mm f/1.8. Having heard good things about the Canon FD 50mm f/1.8, I've purchased one of those & an adapter as well, waiting on it to arrive. Meanwhile, I've heard persons say good things about Minolta's lenses. I've seen a mint-condition Minolta MD Rokkor-X 50mm f1.4 for sale for $50 plus shipping. I found this link that talks about the different versions of this lens, I'm not sure which version this is. Anyway, I am considering it, based on many people saying such good things about it, plus of course it's a 1.4 vs 1.8 etc. That said, my thinking is that, as neat as it perhaps it to be able to use different lenses on the Sony NEX via adapters, is there any real sense in having 3 different 50mm manual-focus lenses? (I got the Nikon one for only $5 about 2½ years ago, it's in rough shape but optically it seems fine and the focusing and f-stops work fine.) Or is there something special about a Roxxor X 50mm f/1.4 that makes it a worthy stand-out lens from the others? Note: I mainly would use such a lens for portraits of my kids & other such portraits. Depth of Field Also: I am finding out from first-hand experience just how shallow depth-of-field can be. Yesterday I took shots of my son, using the Nikon, at f/2 and f/2.8 from 4 feet away. Wow you talk about shallow depth of field. It was HARD getting the eyelashes in focus. I think I saw later on from a depth-of-field calculator that I had about .16 feet of depth-of-field at f/2.8 or something like that. Wow. That's about 2 inches. No wonder it was so hard getting the shot in focus. Anyway, my question is, what is a good app for depth-of-field calculations for an Android device? Also, I noticed that the online calculators I used ask you what camera you use. I'm not understanding why that matters. I understand depth-of-field varies based on how close you are (close-up, shallow; far-away, deep) and the focal length (wide-angle, deep; telephoto, shallow) as well as obviously the f-stop, but I didn't think the CAMERA mattered.