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View Full Version : 7D movie mode: Zoom impossible exposure wise.


francoisdriessen
26th of October 2009 (Mon), 10:36
In using the 7D in movie mode:
Cinematography rule: pulling a zoom without adjusting your aperture will cause the f number to change. (by nature of the definition of f stop number).

Problem with the 7D is that as you zoom, it automatically pulls aperture in 1/3rd stop increments back to the set F number you started on, causing exposure jumps in the shot. (I'm not talking about Tv/Av auto exposure modes - in M mode in stead of letting nature determine the F as you zoom it keeps adjusting it to stay at the digital setting the body has it on. ) E.G.: 135mm/f5.6 zoom out to 28mm should be 28mm/f3.5, but the camera takes it un-gracefully to 28mm/f5.6

Called Canon to see if there is an override that would allow the F to slide, but had no luck so far. My gut feel is by nature of the 7D's operation, Zoom is not a feasible cinematic technique shooting movies with the 7D.:cry:

Anyone out there maybe has a workaround that might bring the (subtle) joy of Zoom to 7D?

gotak
26th of October 2009 (Mon), 10:43
Did you try a constant aperture lens?

Wouldn't keeping the same aperture be the correct way to do this to keep exposure constant? I can see it being disconcerting with it doing the change in steps but maybe a fixed aperture lens would solve that problem.

benesotor
26th of October 2009 (Mon), 10:46
Zoom in PP if it's not by much.