Meet the DR650. It’s just like a Stouffer chart, except it only cost me $6.50. It’s just a sheet of .3 ND gel layered on top of itself. Each step is a stop. The idea is to spot-meter the square marked with the gaff tape, and see what I’ve got to work with with dynamic range over and under it. A general guideline when shooting print film is 5 stops over, 5 stops under. Let’s see what we get with the 7D.
Results (neutral picture style, contrast set to -4 (min)):
Photo mode: 9 stops, including black and white. And that’s being generous. Probably more like 8.5. The 4th stop over the key is blown out, and the 4th stop under is black. The 3rd stop under is pretty close to black, judge for yourself.
Here’s the pertinent part at full-res:
And here’s how it looks processed in Lightroom:
So you get 3 extra stops of shadow detail at the low ISOs.
Movie mode: This actually has a bit more shadow detail in the initial files. There’s a clear 9 stops, 4 over and 4 under. You can count on detail being held up to the 3rd stop over the key, and 3rd stop under.