A couple of test images from today. Nothing stellar, but worth sharing. Also some screen grabs at 100% so you pixel-peepers can see the sharpness. The grass was shot at ISO160 and the camera was shot at ISO400. This lens is as sharp as I'd ever want a lens to be. Basic edits in Lightroom.
This lens is sweet.
Really nice.
I am going to love shooting with this on my 5D MK II.
If you are on the fence about getting this lens, get it.
My mount is very slightly tight, but nothing bad.
Tight in a bayonet style mount is good anyway.
I wish many of my other lenses fit as good as this.
Many of my Canon lenses have a bit of rotational slop.
Ordered mine a few days ago and just got a tracking number today not happy but I am excited to get this little beauty and before anyone says anything I already have a buyer
"The EF 40mm f/2.8 STM utilizes a gear-type that allows the lens to achieve an ultra-compact and lightweight design; whereas the EF-S 18–135mm f/3.5–5.6 IS STM uses a lead-screw type, which prioritizes AF performance, offering the smoothest and quietest operation."
Just like there are a few types of USM, there are a few types of STM.
I guess he mentioned IQ. Speed (beeing faster) is not always the point. My 1.4 was nice at 2.0-2.8 and good at 4.0. Imo a lenses quality should not be mesured by its power alone but by its IQ, too.
A 1.4 that is usable at 2.8 does not give me any more, then a great (unexpensive) 2.8, excellent wide open. The 5D II AF system is not worth anything when you expect more then center AF and recomposing.
Addition:
Imo it is a mess, that Canon offers a 1.2 L but no 50mm else that could keep up with IQ any 150$ 50mm lens 25 years ago did (without af, of course). 50mm 1.4 does not. 1.8 does, if you get a good copy. Those lenses should get an "L" or "II" version before a 24 or 28 gets IS.