Canon EF 50mm f1.8 STM
Canon finally did it and released an affordable decently-built 50mm f1.8 for our Canon DSLRs. While obviously this lens is made for photography, many of us will use it to shoot video as well. Canon knows this, that's why they included the new STM technology so noisy auto focusing won't be picked up on the in-camera audio. Unfortunately they didn't include IS which would have been much more useful than the IS they put on their 28mm and 35mm primes. IS is useful on longer focal lengths like 50mm and longer, not 28mm, especially in photography. IS is useful for video at any focal length and would be great on this 50mm, but the price would be a bit higher I imagine.
The newer STM focusing is great in manual mode. It's very smooth, smoother than my old EF 50mm f1.4 USM, and much much smoother than the EF 50mm f1.8 II, which barely even had a focus ring. It's nice that Canon is putting effort back into lenses for both photography and video...I think it's helping both photographers and videographers who use Canon products. Back in the 1990s when the version II came out, no one even dreamed of shooting video on an SLR, so that's why the focus ring was a joke; they figured people would shoot in AF mode exclusively.
Now that DSLRs shoot video, we're being blessed with better lenses. While STM is not perfect, it works just great for manual focus pulls. I love this lens.
I feel like it's even sharper than the version II or the f1.4 USM. I have no proof, and it doesn't really matter, but I swear this newest 50mm from Canon is the sharpest lens I've used, for video or photos, on my Canon 5d Mark ii. I shot a wedding recently and some of the photos seemed almost too sharp, something I hadn't seen in the 5D as much as in, say, the Nikon d800. Wide open at f1.8 up to about f2.8, you will see some definite degradation of the image on the edges of the frame, but with this new lens even the blurry edges of the image look better than when using other lenses. I guess that's thanks to better coating technologies.
Color seems neutral and just the same as other Canon lenses. This is no big deal as you'll always tweak color in post. My favorite color tool in FCPX is "White Balance Plugin 2" from My FCPEffects. This gives you very intuitive control over color compared to the built in color wheels in FCPX.
If you only shoot video, a nice older Nikkor 50mm like the f1.8 or f1.4 AI or AIS are probably better options for long term use, as they're made of metal and most of them are from the 1970s and are still working fine, proof of their quality. This Canon lens probably won't be functional in 20 years, but we shall see.
Other 50mm lenses for full frame EF mount are the Zeiss primes. You'll pay a lot for these and personally I don't think the image you get will be much better than from a Nikon or Canon lens, especially in the 50mm category. There are also cinema lenses now that cover 50mm that are probably better for filmmaking. Check out Lensrentals.com to try some for yourself for your shoot.