I recently picked up three new lenses for my Canon 550d. They are all actually old lenses, but they're new to me. All of them are manual focus lenses from the 70's and 80's and they are all from different manufacturers. This means they require lens-mount adapters so they will fit on my Canon.
The first lens is the only one that I truly sought out. I wanted a nice normal prime lens for the 1.6 crop factor chip on the 550d. I settled on a Nikon 28mm f2.8 Series E lens. It was quite inexpensive and is very sharp. Its 35mm equivalent focal length is ~45mm. This is my new standard lens.
The second lens I picked up when I was in LA earlier this month. My sister has possesion of my grandfather's Olympus OM-1 and attached to it was an F.Zuiko 50mm f1.8 OM lens. I already own the Canon 50mm f1.8, but since the Olympus is manual focus it is going to be much nicer for video work. I will post comparisons of the two lenses eventually. I am curious to see how they compare.
The third I picked up on a whim at a camera shop here in Zürich. It was in a bargain bin for CHF 30 and I thought I'd take a chance. It is a Minolta MD TELE ROKKOR 135mm f3.5. I was taking a chance on this lens because I was not sure if it was adaptable to Canon or not. Luckily it was. Unluckily I picked the wrong adapter. There are two different adapters for Minolta to Canon -- one has an optical element and the other doesn't. I went for the one without hoping it would be ok. Unfortunately the lens won't focus to infinity. It still makes a great macro lens though. May someday I will get the optical adapter. Does anyone know which minolta lenses focus properly with out an optical adapter?