Regarding those "other factors", as they say - "it all depends.........". For example sometimes you can miss the shot while futzing with the tripod. There are less exreme examples as well. Sometimes one can be a prisoner of "best practice" without ever knowing what one is really sacrificing with "second-best practice". But as I said, I'm not really arguing against Motherhood - I'm just trying to elicit an exploration of more exactly what the trade-offs really are. Marc's demo is interesting in this respect - but it raises a number of interesting questions, like why the differences in processing between the two images - does that do anything to the comparison, the fact that much of the background is out of focus anyhow, whether the bushes in the foreground were being moved by even the slightest breeze in either image, etc. But it's a start to a comparative analysis which perhaps could benefit from nailing several variables a bit tighter. When this dismal weather in Toronto gives me a comfortable afternoon with the right lighting to work on my favorite testing site, I should try my hand at some of this and see what I come-up with. Sometimes we learn surprising things when we "bother" to test our assumptions!
I'm pretty sure I kept all the factors the same between the 2 shots. The only difference was time the latter, was taken about 45 minutes after the first so the light was different, but the settings in the camera and C1V4 were the same. It took time to look at my initial shots and then assemble the vibration isolation device.
PS I do get some frame to frame variance with the p30/C1 combination that I have not figured out yet. Perhaps C1 has some intelligence built in and out smarts you by making decisions without your knowledge?