Manual Settings vs Auto

James474474 · Sep 7, 2018

I completely get the logic behind using manual settings to avoid exposure swings. However, a common technique is to tilt the gimbal to reveal a subject which in my experience causes the exposure to change significantly.

I use ND filters to get my exposure in the right ballpark (e.g. 2x framerate) but I seem to get better results by using auto mode so that reveals maintain correct exposure. When I switch to manual mode I am constantly choosing to underexpose the shadows or blow the highlights and the MA sensor isnt hugely forgiving of exposure errors (unlike a dslr).

What do others do/think to work around this challenge?

TIA,

CanadaDrone · Sep 7, 2018

It depends where you're shooting. I almost never have exposure swings when doing 'the gimbal tilt', but I am also often purposefully flying in as even lighting as possible (either full sun or full cloud cover).

Any camera can only expose for one single thing at a time, so really there is only 2 choices and it's entirely up to you:

1) Try to find a happy medium exposure suitable for the entire flight (underexpose a tiny bit if anything, and ALWAYS shoot at ISO 100).

2) Use auto and deal with constant minor exposure changes and large momentary exposure changes depending on the scene.

I fly in manual mode 100% of the time and very rarely do I get caught off guard with exposure. You should also not be using AUTO WB if you can help it. If you are flying in an area with mixed sun/shade for example, there is really nothing you can do, you pick one of the two above options and deal with it.

The only time I can think of where a gimbal tilt would make a huge exposure swing is if the ground was really dark and the sky bright, or vise versa (i.e. maybe bright white sand vs a grey cloudy sky). Most of the time the exposure difference is not that significant between the ground and the sky unless you start to point the camera near the sun. If you are trying to film an area that is causing you a lot of grief with this, wait for weather conditions to even out the exposure for you - in the moment though there isn't anything you can do to combat the fact that a camera can only see a single exposure at any given time.

James474474 · Sep 10, 2018

Attempted this over the weekend, perhaps I am attempting something the MA sensor cannot cope with:

A combination of dark pine forest and very light sky make for a significant dynamic range.
The manual exposure looked more contrasty for the initial part but the highlights blew out in the top left of the frame.

When attempting some similar maneuvers in reverse (tilt down) the exposure swings were really obvious with the green of the forest suddenly becoming super bright!

James474474 · Sep 10, 2018

Looking through a screen recording of the footage the auto exposure changed from 1/40 to 1/240 so 2 1/2 stops. I manually set exposure at 1/120

lollip · Sep 11, 2018

I have the same issue. What I usually do is first set exposure for the brightest area (e.g. sky), sometimes even tilting the camera upwards. Then I shoot the scene, and try to adjust in post. I have no idea if this is the “optimal” way to do things. My limited understanding is that you cannot correctly expose for everything, and the advantage of manual is that you can at least make trade offs according to your artistic preferences (if you’re lucky enough to have such tastes ^^). Not easy...

MrRobville · Sep 11, 2018

There's no golden method, however the biggest advantage of shooting manual is that you have no exposure "jumps" like when transitioning from a relatively dark forest to a bright sky. The auto exposure could suddenly make the forest pitch black without any fluent transition, which doesn't look appealing.
Depending on the scene, auto mode could work fine, but if you can, I'd recommend shooting manually any time. I've had a couple shots ruined which looked fine in the video feedback, but on the PC had loads of exposure flickering because tiny bright objects passed the lens, causing it to instantly underexpose the entire shot for a split second.

Same goes with the decision to either overexpose or underexpose your shot to compensate for the dynamic range. If the sky is the subject of the shot and you want to capture it fully, then underexpose the shot a bit.
Is the subject you're tilting away from is important to clearly see in the shot, then you may decide to overexpose it. Just keep in mind that underexposed shots with blown shadows are usually easier to correct in post rather than overexposed shots with blown out whites. (e.g. a lot of vintage image filters clip the shadows quite a bit, but rarely the highlights)

Last tip: shoot footage in a D-Cinelike color profile, which is a flat color profile that allows for a more dynamic range to be captured. This is also very useful if you're planning on editing and color correcting your shots in post.