Originally Posted by victapilot
Sparklet's method is good.
For AV it is best to have a lot of distant detail and not too much sky to get the best result. Sky is easily compressible by JPEG, so will give low numbers. A lot of foreground detail will give a "false positive", unless that's where you want focus to be. Here are a few examples, you can see as sky increases, the file size decreases, to the same point as a black room.
Same comment for large areas ofshadow which will compress to small size due to no contrast detail
I agree, and this confirms what I mentioned up front that the exact same scene and lighting needs to be in all the sample images for the file size to mean much. In the samples I posted, the images on either side of "best" vary by only 5k or less in size, but the eye can easily pick up the changes in various parts of the scene (near or far).
And as you implied, it's necessary for the scene to have objects at distances you want to be in reasonably good focus. For me, that's not all very distant objects since I use my camera on planes as well as a quad that I don't fly very high or very far out... mainly to capture closer in ground subjects. Even with my AV planes, I like the ground to have reasonably good focus on landing approaches, etc. The "far" outdoor image scenes I posted pretty much reflect that preference. So, I may need to compromise for my "best" focus, or have different cameras for different video objectives.
Everyone will have their own video needs, so they need to take all this into consideration for best results.