The 'Goto', the 'One', the 'Default', the 'Super Tak, Nifty Fifty', the 'Always On', the 'Can Do' lens. If you every buy a manual focus lens may I suggest you can't go too far wrong with one of these. It was the first Takumar I bought. Not too expensive, well under a hundred pounds for a good one. Sharp as a knife over f5.6 and beautiful dreamy depth of field below. Bit soft in the corners at f1.4 but so what. Its what makes these lenses so nice. The build quality of all Takumars is second to non. All metal and precision built to last. The friction on the long focus throw and the click of the fstop is just right even after forty odd years This goes for all my Taks.
Here's a couple of pics of the lens itself with its metal hood.
And here's a few examples of what it can do. Mine has a yellowing very slightly in the rear element. A common occurance in these particular Taks. If your shooting BW its not an issue, if your shooting digital like me its not an issue either. Light room or your camera white balance will sort it out. I did buy a lamp for lizards that pumps out lots of UV rays to cure it. You can either put it on a window sil for a week in California or a tin foil lines shoe box for a few days with the lamp inside. I may get round to it.
Fifty millimeters is a very nice length. Its close to what your eye see's. Its on my 6D as a default lens. I can't say a bad word about this lens.