This lens is a beauty! I felt for it the first time I use it and won’t let it go.
First, I’d like to emphasise it’s an wonderful portraiture and low dim lens. The airy, dreamy look it can offer to a picture cannot be compensate by any photoshopping. Secondly, the price-value rate is simply incredible. You cannot get any professional than that on so little money. Actually, you cannot get much more professional than that on no matter how much money.
A number of photographers complained about its bokeh and highlight halos – if any, they are quite pleasant and artsy. Some criticism was raised by the sharpness level of some shots at 1.4, but in my reckoning such issues are caused mainly by calculating wrongly the hyperfocal distances.
However, there are some disadvantages that you should be aware of when purchasing it:
The Canon 50mm 1.4 USM is a high quality and maintenance lens, and any repairment work on it would cost you at least half of its value – therefore, get it new and buy an extended warranty; alternatively, get your tools ready to dismantle it and check the focus ring for dislocations, as the AF option/focus ring might cause you some troubles, especially when sloppy handled 🙂
The Canon 50mm 1.4 lens is a full time manual focus lens. Basically, this means you can manually focus the lens without switching it from auto focus to manual focus. Generally, full-time manual lenses are endowed with a “Ring USM” focusing mechanism that uses a differential to allow the auto focus motor motor and the focusing ring to operate at the same time. However, the Canon 50mm 1.4it’s the only lens in the EF system to use the extra-small, inferior Micro USMYes. In order to simulate the “Ring USM” behaviour, the micro USM would need a separate clutch. It’s natural to expect some failures. I’d play safe on this, and don’t abuse the FTMF.
Also, the focus helicoid (making the lens going in and out as you focus on the subject) has a poor design and any pressure on it can cause damages. Therefore, it is recommended it to use or store the lens with a circular-shaped bayonet style hood at all times. Opinions slightly differ on whether one should reverse or not the hood for storage to better protect the front of the lens and the focusing ring.
Similarly to storing other lenses, you should focus it at infinity when parking it (or fitting filters and lens caps), as this is the most inward position, retracting the lens as much as possible.
No one who did that ever had an issue 😉