Canon 50mm f/1.2L has always been a lens with "character" to me, it is few of the lens in the world that is able to produce that f/1.2 bokeh at 50mm. The photo you can capture with it always gives you that special look that very few lens in the world is able to produce, or probably non at all.
I use it mainly for street photography and some portrait to give my photos some "character".
There's been some confusion to some people on the sharpness of this lens that I come across from time to time. To me sharpness isn't much of a concern because I use this lens for that f/1.2 and 50mm perspective, not for being the sharpest lens out there or the fastest focusing one, I'm sure it's the same reason for those 50mm f/1.2 users.
But sometime I wonder how sharp is this lens actually? To answer that question, I did some test myself.
I have my camera fix on a tripod and capture the subject in my home studio at a fix shutter speed of 1/100 and ISO 100, subject light up with flash. Focus manually on number "18" of my lens on M3 as pointed out below:
After capturing each image with one stop different, I crop out a portion of the image as illustrate with a white square below:
And here are the results:
It's clear that at f/1.2 the image is very soft, but one stop down and you get quite a big different in image sharpness, and it gets progressly better when you stop down furthur and tops out at about f/5.6 to f/8 until diffraction sets in. If you don't know what is lens diffraction, I've written an article on my wordpress blog here.
24-70 f/2.8L and 100mm Macro f/2.8L IS
I also run a same test with my 24-70 f/2.8L and 100mm f/2.8L Macro IS for some comparison. The test is done exactly the same as with 50mm f/1.2L except the zoom range is fix at 50mm for 24-70 f/2.8L and I pull back the camera to match the perspective of a 50mm for the 100mm f/2.8L Macro IS
And here are the results for 24-70 f/2.8L:
As you can see, the sharpness tops out at about f/5.6 to f/8 region until lens diffraction sets in.
So how about 100mm f/2.8L Macro IS which is famous for it's sharpness? The results are below:
Similarly, sharpness tops out at about f/5.6 to f/8 and lens diffraction sets in after. But if you also notice, this lens is sharp even at wide open at f/2.8!
Now let's put their sweetspots together for comparison:
100mm f/2.8L Macro IS is the clear winner here, and 50mm f/1.2L definately wins 24-70 f/2.8L in sharpness.
The 180 Megapixels
Brought out my Canon 5Ds with 50mm f/1.2L few days ago for some landscapes capture, and end up with a 180 megapixels panorama that once again impress me with the details that this camera is able to capture and also what my 50mm f/1.2L is able to deliver!
If you zoom into the photo, you might even be able to make out who are scrolling along the reservior bank as I tried to illustrate below:
Oke, not exactly highly detailed but you might be able to recongnise if your friend is sitting there, you get the idea. I also crop out different part of the image to illustrate the details that this image is able to deliver.
<Pretty nice details for a low lighting conditon exposure I would say.>
Once a while you come across a lens that gives you that something that no other lens is able to provide, Canon 11-24mm f/4L and Canon 85mm f/1.2L are some of them. To me, Canon 50mm f/1.2L is also a lens that sit in the same category as the two. It will always be a lens I use when I want to create that special "character" in my photo, not for sharpness or focusing speed, but for something "special".