The choice of top-quality 50mm lenses for Canon's full frame is not great. These are Sigma Art 50 1.4 and Canon 50 1.2L. If you take it new, then the prices are 70 and 120 If you take a bu on ebay, then the prices are 50 and 60 In the picture, there is no big revolutionary difference between these glasses, sigma is a little more colorful or something, Canon fascinates at 1.2. But there is a difference in weight. With 5D Mark 2 Sigma weighs 1728 grams, Canon 1506 grams. When the camera already weighs 1.5 kg, this is not the case when they say: "load more, the extra 220 grams no longer matter." Just there, any increase is directly felt strongly. I will give test shots with 2 lenses head-on, which I took in mode A with auto iso on the 5D Mark 2 in the open. No processing for clarity. I made a conclusion for myself. For shooting at home, I would shoot on Sigma, the child turns out to be more colorful or something and sharp at 1.4 On the road, I would shoot with a Canon to make it comfortable to carry the camera, and the pictures with it are great. It outperforms Sigma at f2.0 in Lenstip sharpness tests, for example. And at f4 Canon gives 50 lines per millimeter, which is inaccessible to the "sharp" Sigma. In general, 50mm is a must have lens. I will attach 1 object also shot on Sigma 35 Art 1.4 for comparison, you can see that 35 distorts vertical lines and faces. Direct proportions gives only 50mm, as our brain sees through the eyes, this is very close to how our brain sees the proportions of objects. And I think here you can have 2 lenses and Sigma as a different scheme and something new and Canon. What can I add Canon 50 1.2L beats on 5D Mark 2 in Servo AF mode 10 frames out of 10 in focus at f1.2. Sigma 50 1.4 is also good at 90% focus on the target, unlike 35 1.4 even set up by the docking station, which produced 50/50 sharp frames. 35 1.4 is good only in Live View, a lot of such reviews are written on the market and mine is also the same as the owner of all these lenses. Well, you choose. Now I have left both lenses, for travel I will choose the Canon 50 1.2L, for important shooting I will choose the Canon 50 1.2L as it is important for me to always be in focus.