EOS R6 - changes exposure on full manual video mode

[Marakor]

Hi there,

I just recorded some videos on the manual video mode. Shutter speed, aperture and ISO are all manually set and autofocus is disabled. For some reason, the camera still changed the exposure quite drastically on its own during the recording, which ruined the shot. What's causing this and how do I fix it?

[deebatman316]

Did you change environments if so then the exposure will be wrong. Is Safety Shift on if so it will override your exposure settings. If the settings are incorrect for the lighting.

[Marakor]

The camera was on a tripod with consistent lighting. I would attach a video, but the site says the link isn't valid so I'll post some screenshots below.

Where is the safety shift setting? I can't find it in my video settings.

[Marakor]

EDIT: I just found the setting. It was already turned off.

[deebatman316]

The light source is flickering so fast the camera can detect it but you can’t. Leading to incorrect exposure.

[Marakor]

Hmm, okay, and how do I combat that? And why does the camera change the exposure on its own on full manual mode? Isn't that the whole point of shooting manual?

[rs-eos]

The exposure is changing due to the light levels changing.  This will become more noticeable the faster your shutter speed is. If you slow the shutter, that should "average out" the flickering light to yield more consistent results.

What shutter speed were you using? Try 1/60 second if capturing 30 fps or 1/50 if capturing 24 fps.

[pedz]

If this is because of a flickering light, then the camera isn't changing anything.  What you are observing are that some frames are taken when the light is on more than when other frames are taken.  As rs-eos points out, a slower shutter speed will average out the flicker and give you more consistent results.  A better solution might be to get a non-flickering light source if possible.

Your camera might have settings for flickering lights.  I don't have an R6 so I don't know.

[Marakor]

Thanks for your answer. So, since it is the light level changing, what do people usually do when they encounter lights like this? This light is coming from an affordable projector that isn't specifically made for photography/videography purposes but it looks great in person with no noticable flickering.

Yeah, I was using 1/60 with 30fps at first but since I noticed banding I changed it to 1/50 with 25fps. This removed the banding but apparently didn't help much with the exposure.

[Marakor]

Yes, the R6 has a setting for flickering lights, but it's not there in video mode, which surprising to me since I feel that it would be especially useful for video purposes.