I own a Canon 77D camera with built-in intervalometer. I can set the interval in seconds between shots and set it to either shoot indefinitely or a fixed amount of shots. When I shoot the sunrise or sunset (a.k.a. The Holy Grail) timelapse I need to adjust exposure (mainly shutter speed) in order to compensate for dramatically changing brightness of the scene. Problem is that in order to do that I need to turn the camera off to abort the indefinite interval shooting, then turn it on, adjust the shutter speed and turn the interval shooting again. This takes time and causes an uneven interval between shots. Is there a way to adjust exposure settings without interrupting the interval setup? E.g. tell the camera to shoot the next frame with a different shutter speed than the previous one.
If this cannot be done with the built-in intervalometer then can it be achieved with some external one?
Or is there another trick to work around it? P.S. I'm using LRTimelapse and Adobe Lightroom for post-processing.