Aperature rapid switching or "aperature burst"

[markjsmccall]

What I want to create is the same effect as a trailing shutter flash photo for use in sports photography, executable in daylight and without the use of a speed light or strobe.     I think this is technically feasible but would require some work on programming a DSLR/mirrorless  body's firmware to test the theory. 

What I believe is necessary is a  camera function were the camera can immediately switch from a pre-programmed aperture and shutter speed (say 1/10 of a second) to a second pre arranged setting (such as 1/1000 of a second with a corresponding aperture shift).  This would happen within a burst of 2 frames as fast as possible after each other for a given model.   The photographer could then overlay and blend the images together in post processing to show the long shutter exposure streak effect of moment but combined with the frozen final motion captured by the second shot.   I think this would be an impactful imaging form when used in some sports photography contexts.   I have a 7D MK II and a 70d but have access to a 5d3 so any of those as a test build would be awesome.

Another approach would be the cycling of the aperture by pressing or releasing the programmable button on the front of the camera used for DOF preview?

[garry23]

Your idea could be accomplished in Lua.

In fact I did a similar thing here, fir focus stacking:  http://photography.grayheron.net/2018/01/an-alternativenew-approach-to-focus.html

The idea, using Lua, being to take two images at the 'same' exposure by adjusting aperature etc.

In other words, your base exposure at, say, 1/10 is image one, then, in Lua, calculate and reset the shutter time to 1/1000, adjusting aperature and ISO to achieve the same exposure.

You will have to live with the Lua image to image delay.