Last version of the Takumar 55mm f1.8. Note rubber skin on the focusing ring. Click for larger.
Let me say this: if you are just starting to play with manual focus lens, and you don't use a mirrorless camera or a Nikon, buy the SMC 55mm f1.8 lens, instead of a cheaper Minolta or Canon FD equivalent. The Takumars are beautifully built, very small, optically brilliant, and focuses like no other in its class.
Other than a bit "slow" with the maximum aperture of f1.8, I see very little fault with this lens. It's sharp, has good bokeh, and still relatively cheap. Even if you don't like it, when you sell it later, you will not likely lose money. Trust me, if properly kept, this lens will last many decades more.
Caddy - Canon 5D Mark II & SMC Takumar 55mm f1.8 @ f4. Click for larger.
Da Shoe - Canon 5D Mark II & SMC Takumar 55mm f1.8 @ f1.8
Graffiti - Canon 5D Mark II & SMC Takumar 55mm f1.8