The Canon 50mm f/1.8 is one of my favorite lenses that I own. I purchased the plastic fantastic, as it is called (the lens is made entirely out of plastic), a year ago at Best Buy for the inexpensive price of $110. Since the lens is made out of plastic, this allows the lens to remain lightweight and versatile. I know that if I drop this lens in any way, shape or form, it will break. It is a very precious lens that will treat you well if you do not put it through a lot of abuse.
One thing that surprised me about this lens is how well the 5-blade glass optic was made. The glass is very sturdy and does not smudge or scratch easily. I found the autofocus to be spot on with this lens. However, the autofocus motor is very noisy, and sounds very mechanical. Also, the manual focus ring rotates while in autofocus mode. Be sure to keep your fingers away from the manual focus ring when autofocus is engaged, or else you might strip or damage the manual focus ring.
Sharpness is decent wide open at f/1.8. I have found that the lens is sharpest two stops above wide open, at f/2.2. Compared to its two counterparts, the Canon 50mm f/1.4 USM and Canon 50mm f/2.5, sharpness is about the same. Sharpness is fantastic at the center of the frame, with the photo generally getting softer the farther out to the corners you go. Bokeh produced by this lens is sub par, with the bokeh tending to be very soft and misshapen. Color reproduction is great with this lens. Colors seem to “pop” and look alive and very vibrant. Falloff (darkened corners) is very prominent from f/1.8 to f/4. Falloff becomes diminished and hardly noticeable once f/4 has been surpassed.
The lens uses a 52mm filter thread. Adding a filter to this lens doesn’t seem to make the lens feel any heavier or imbalanced. A lens hood is optional. However, the lens element is actually sunk into the lens body, which means that a lens hood isn’t really necessary. I think that this is a great design feature that Canon decided to augment.
Overall, this lens is fantastic. The lens might be made out of plastic, but with its phenomenal color reproduction, sturdy glass optic and fast autofocus, this lens cannot be beat, especially for the price. I would recommend that every photographer try to purchase this lens, or at least try it out. You will be blown away by how well this lens performs in any given situation, especially in low light.