C-41 overexposure - What is effect on resolution and sharpness?

Does anyone have any numbers (RMS or MTF) to show how much the
resolution and sharpness of color negative film (print film)
deteriorates when the film is over-exposed by 1 or 2 stops?

For example, exposing 100 speed film at EI=50, exposing 400 speed film
at EI=100 and EI=200, exposing 800 speed film at EI=400 and EI=200.

Overexposure of color negative film (but not b&w negative film) is
reputed to decrease the perceived graininess because its dye clouds
overlap more, but I suspect that some tradeoff probably is paid in
decreased resolution and sharpness. I understand that negative films
give better sharpness when slightly underexposed.

camera critter wrote:
Does anyone have any numbers (RMS or MTF) to show how much the
resolution and sharpness of color negative film (print film)
deteriorates when the film is over-exposed by 1 or 2 stops?

Datasheets of movie film graph both grainyness and sharpness
against ISO exposure value, but I've never seen that for still film.

For example, exposing 100 speed film at EI=50, exposing 400 speed film
at EI=100 and EI=200, exposing 800 speed film at EI=400 and EI=200.

It depends on the film. Steve Dunn did a study with Supra 400
(IIRC) and decided it lost sharpness at 100 but not much at 200.
When testing a film I try bracketing to see the grain/sharpness
tradeoff. Grain often improves at +.3 EV but sharpness doesn't
usually suffer until way beyond that.

Overexposure of color negative film (but not b&w negative film) is
reputed to decrease the perceived graininess because its dye clouds
overlap more, but I suspect that some tradeoff probably is paid in
decreased resolution and sharpness. I understand that negative films
give better sharpness when slightly underexposed.

I'd say that most negative films attain optimal sharpness when
correctly exposed. When underexposed, they grain up (especially
in shadows) thus reducing acutance.