"Simply not true, with all due respect for your work. I suggest you to make the test as described"
Have I been dreaming? Maybe I don't understand your point, but my experience tells me though worded wrong, practically speaking on a job, Chris is right on.
For many years I shot 35mm slides along side my 4x5 transparencies, because there wasn't a good duping service here, and architects needed 35mm slides for design competitions. So I would use a lens on the 35 that was comparable in field of view as the 4x5. Say a 28 lens on the 35 when I had a 90 on the 4x5. Given the same exposure (f stop actually) I had considerable more depth of field in an 8x10 enlargement with the 28/35 combo than with the 90/4x5. Right? What am I missing here? See this from Wikipedia too:
"When a picture is taken in two different format sizes from the same distance at the same f-number with lenses that give the same angle of view, the smaller format has greater DOF."
"To maintain the same field of view, the lens focal lengths must be in proportion to the format sizes. Assuming, for purposes of comparison, that the 4×5 format is four times the size of 35 mm format, if a 4×5 camera used a 300 mm lens, a 35 mm camera would need a 75 mm lens for the same field of view. For the same f-number, the image made with the 35 mm camera would have four times the DOF of the image made with the 4×5 camera."
What am I missing? Chris is right. Right?