Low ISO dynamic range (100-400)

If I'm looking at the charts for my 5dIII right, it seems as though there is a very slow drop off in dynamic range at the first few stops, and it isn't until 800+ that it really starts to tank with each stop. Is this correct? Not quite sure why it works like that. I have a shoot this week and I was thinking of just setting it to ISO 400 and forgetting it as opposed to using auto ISO, which has been working well for me.

Silver-Halide wrote in post #18038656
If I'm looking at the charts for my 5dIII right, it seems as though there is a very slow drop off in dynamic range at the first few stops, and it isn't until 800+ that it really starts to tank with each stop. Is this correct? Not quite sure why it works like that. I have a shoot this week and I was thinking of just setting it to ISO 400 and forgetting it as opposed to using auto ISO, which has been working well for me.

yup, you are reading it correctly. I don't remember the specifics, but all current Canon's (outside of the brand new 1DX and 80D i believe) have similar DR profiles along the low ISO end. I have found 100 and 200 on my 6D to be pretty much indistinguishable in DR and noise. I have no problem shooting at 400/800 and expecting great quality.

a year or so ago, while the argument was that Nikon was much better at low ISO, by ISO 800 Canon was actually slightly ahead in DR.

K thanks. I'll try it out for getting ready and candid shots and see if I like it better. For the dramatic, sunset stuff with added flash I'll be at 100 ISO out of habit. The dynamic range is more an issue for when I'm shooting landscapes for fun, as it would be nice to be able to just underexpose and lift shadows at sunrise and sunset without the need for HDR.