I found out some basic information on the actual exposures used when shooting 1080p video with the 5D2. It is explained in detail here, but that thread is long and full of useless stuff so I'll give the final conclusions in this post.

http://www.dvinfo.net/conf/canon-eos-5d-mk-ii-hd/146718-5d-mark-ii-shutter-exposed-part-ii.html

If you lock the exposure before shooting and the readout is 1/40 or 1/50, you will get an actual exposure of 1/50. If the readout is 1/60 or 1/80, you will get 1/100. If it reads 125, you will get 1/125.

I found out some basic information on the actual exposures used when shooting 1080p video with the 5D2. It is explained in detail here, but that thread is long and full of useless stuff so I'll give the final conclusions in this post.

http://www.dvinfo.net/conf/canon-eos-5d-mk-ii-hd/146718-5d-mark-ii-shutter-exposed-part-ii.html

If you lock the exposure before shooting and the readout is 1/40 or 1/50, you will get an actual exposure of 1/50. If the readout is 1/60 or 1/80, you will get 1/100. If it reads 125, you will get 1/125.

So is there no 1/30????

So is there no 1/30????

As I said in the big thread, I am going to redo the test and include 1/30. But, from what I've seen so far 1/30 would be impossible. I'd wager that 1/50 is the actual slowest exposure time. I'm going to do faster ones also, even though one would be crazy to shoot faster than 1/125.

As I said in the big thread, I am going to redo the test and include 1/30. But, from what I've seen so far 1/30 would be impossible. I'd wager that 1/50 is the actual slowest exposure time. I'm going to do faster ones also, even though one would be crazy to shoot faster than 1/125.The longest possible shutter would be 1/30 minus the read-reset time, which your test shows to be 23us (1/43410 seconds.) The result? 1/30.02. The question is, what did they implement?

Regarding faster shutter times, they are useful for special effects. The Normandy scene in Saving Private Ryan is one of the more famous examples.

In fact, we just used a fast shutter the other day when I was cutting steel with a ceramic saw blade. Sparks were flying all over the place! With a fast shutter, the sparks have enough of a tail to show motion, but they come and go in a random way. A long shutter would give long tails and a different, smoother feel. Personally, I liked the fast shutter. It's more brutal. ;)

I don't think you need to test them though. My test shows that we get fast shutter speeds that line up fairly well with what the camera shows. I don't really care about an accurate number. Just dial it up to get the specific look you want for the specific situation. In general, we can only crank it as fast as the light allows anyway.

Wrong thread. Moved it...