The manual says that when using CLog the iso should be set to 850. Does this mean a minimum of 850 or 850 exactly? Also is anyone using the Cine 1 profile. if so whats been your experience with it. I just srating to branch out from using the wdr profile.

The manual says that when using CLog the iso should be set to 850. Does this mean a minimum of 850 or 850 exactly?

850 is the base sensitivity but C-log works at any of the ISO speeds. As you change ISO the dynamic range stays consistent at 12 stops but where it falls between light and dark shifts. 850 and higher gives you the most headroom.

Here's a diagram:

http://learn.usa.canon.com/app/media/images/articles/c300_canon_log/dynamic_range_chart__fs.jpg

Be very aware that using ISO BELOW 850 can lower your dynamic range.

Watch your waveform monitor and see the way highlights get pulled down in relation to the shadow details as you use lower ISOs.

Be very aware that using ISO BELOW 850 can lower your dynamic range.

In the shadows, not on top. I tend to shoot 640 ISO when I want a little more headroom on top and know I won't be dealing with much shadow area.

cine1 vs wdr gamma

850 or above is the recommendation. The same applies for WideDR.

Go below that and you will notice clipping in your image. We prefer to put on an ND filter and then up the ISO to compensate than go below 850.

See this image from canon

Kevin, the image Danny posts kind of says it all.

That image, and much more information, is included in a series of White Papers Canon has released on the Cinema EOS system. You can find them on Canon's home page.

Canon Log has been designed to deliver 12 stops. It maintains the same dynamic range over all the ISOs, but the point where 18% gray lands may shift.

The reason for the ISO850 recommendation, is because it is the lowest ISO (least noise) that still provides maximum highlight protection.

You can get a cleaner 12DR stop image by lowering your ISO, but you will lose some highlight protection/range. Still, this might be exactly what you need in some scenarios.

I know there's lots of info on this, but I could use a hand putting some of it in perspective. When exposing for clog, do I use the wave form monitor like I would any other picture profile? From what I've read, it seems that skin tones should be down around 65 IRE and that whites should not go above 75 IRE. Does this mean that at no point should the wave form monitor ever go above 75 IRE?

"White" means 'reflected white', as in a lit white wall or shirt.

Light sources (e.g. practical lights, shooting into the sky) and specular highlights will all go above and sometimes blow out.

There are many threads on this. The answer is already out there. You don't have to look far. You should also find a thread discussing the waveform monitor a couple of threads down.