Does anyone use this feature? I have a 17-55 EF-S lens and a 70--200 EF lens. The C100 has a correction for peripheral illumination for EF-S lenses. I'm fine using it, but I know myself enough to predict that I'll forget to switch back to normal when I switch lenses. How important is it? And what is the difference between the EF-S lens setting & peripheral illumination setting? When I enable the EF-S setting, there is distinct magnification. When I enable Peripheral Illumination Correction, I can't notice a difference. I wonder why there are two options. thx

I don't use it. As far as I can tell it digitally zooms in slightly from the 1920x1080 image so, even though it's barely noticeable, it MUST degrade the image resolution slightly (even though that 1920x1080 image is derived from 4 times as many pixels on the lovely sensor).

I am leaving it off until I ever feel a need to use it. After all, if need to crop in on a shot then it's easily done in post.

Pretty much what I wanted to hear. Thanks!

I should add vignetting is not a problem on the two Canon EF-S lenses that I have, the 17-55mm and the 10-22mm.

I have heard one or two people complain about vignetting with the Canon 17-55mm (on a C300), maybe I just have a good (well aligned) copy. Also, if you wave the camera around violently with EF-S lenses (with IS) it may vignette a little when the IS is working to correct the shot...but then I don't shoot like that ;-)

Perhaps on some (lesser quality?) EF-S lenses the need for this option becomes more important (i.e. all shots would vignette so it would be a pain to do all the correction cropping in post) - but I stress I cannot say I know that to be true from personal experience as all the other lenses I have (apart from the above two) are EF lenses or Olympus.

Will be interesting to hear what others have found.

I don't use it either. But some EF-S lenses vignette, especially the 17-55mm f2/8. Here's a test I found: Vignette on EFS 17-55mm lens on Canon C300 (http://ow.ly/haV1a)

I only use FF lenses, wise to invest in L glass. I have a feeling they are about to get more expensive.

I just tested mine with and without the correction and think I will keep it off.

I only use FF lenses, wise to invest in L glass. I have a feeling they are about to get more expensive.

Same here. My first was the 17-40 f/4 L series and it works great on my C100. I don't think I'll purchase any EF-S glass just because I am also worried I'll forget to toggle that switch.