Fog flying, need advice.

[Sctcorolla]

So there's a creek/small lake close to my house and during early mornings it gets this fog like misty condition above the waters, not thick fog just light fog. I want to film in this condition, I think it looks beautiful. Do you guys recommend it and what camera settings do I use and do I turn off visual sensors and what not. Please advice, thank you.

 

[DodgeP]

A word of advise for anyone new to shooting video; determine the quality and frame rate and then set optimal shutter speed to 2x the frame rate. Control your light using ND Filters and ISO setting. The unfortunate thing about the Mavic is that you can't really get any usable footage with any frame rate higher than 30FPS so you're going to capture your smoothest video with a shutter speed of 48 or 60. With the shutter speed that low you'll have trouble maintaining that 180 degree shutter rule.

I also suggest turning on the histogram and using it as the sole resource for what your videos exposure is. Far left is the shadow data and far right is the highlight data. Ideally you don't want either level to be up against side or clipped at the top. This way you have some room to work with the file in your post production. I trust my histogram (for exposure) more than I trust my own eyes. Short of having a light meter, you're going to have to get out there and run a few test flights to see which settings will work best for the way you want to capture the fog.

Fog can exist in various light levels so that's why you'll have to pay attention to your exposure via the histogram.

 

[Sctcorolla]

Cool, thanks Dodgep. Is fog going to mess with any of the vision sensors or OA?

 

[Kilrah]

Yup, disable OA. Bottom sensors seem OK with it.
And make sure you're not flying in freezing temps.

 

[Sctcorolla]

Thanks kilrah, no not flying in freezing temps. Warm California weather [emoji41]

 

[SteelFlyer]

If you can't nail perfect exposure, err on the side of underexposing. It's always better to try and recover detail from underexposed midtones than have area that are blown out and unrecoverable.

 

[DodgeP]

If you can't nail perfect exposure, err on the side of underexposing. It's always better to try and recover detail from underexposed midtones than have area that are blown out and unrecoverable.

What he said! Lol

 

[Red_Raven]

If you can't nail perfect exposure, err on the side of underexposing. It's always better to try and recover detail from underexposed midtones than have area that are blown out and unrecoverable.

Is that the case? I ask because I come from a long background in slr photography and when working with any type of files containing photographs from cmos censor (especially raw files) the recoverable details/ pixels stay in the highlights even into a little burned put areas while the shadow areas keep nothing but noice, no usable details at all.

Is this a documented fact or something that you've noticed in your material?

I'm really curious about hearing the technical facts and reasons on the subject, I'm not at all saying you cannot be right. I simply didn't knew that this was any different in videography.

 

[SteelFlyer]

Is that the case? I ask because I come from a long background in slr photography and when working with any type of files containing photographs from cmos censor (especially raw files) the recoverable details/ pixels stay in the highlights even into a little burned put areas while the shadow areas keep nothing but noice, no usable details at all.

Is this a documented fact or something that you've noticed in your material?

I'm really curious about hearing the technical facts and reasons on the subject, I'm not at all saying you cannot be right. I simply didn't knew that this was any different in videography.

Let me saying that I am far from an expert but do have a number of years experience with using consumer and some prosumer digital sensors especially in video. First off, I shoot probably 85-90% video and very few stills so I come to the issue from that viewpoint. My answer is based largely on my experience and also a lot of studying of others in the field who have tested these things.

Raw photo files have a lot more latitude to play with than highly compressed video. It's much more like trying to edit JPG stills files. I agree with your point about being able to pull detail out of highlights. This happens in video as well but not to the same degree as raw photos. The issue for me is that once you truly blowout the highlights - that is push the luminance values all the way to highest point, no amount of skill or software will get the detail back. It is all full white. The same, of course happens with the shadow details and black if you underexpose a good deal, but in my experience this happens much less. My experience so far with the Mavic camera is that it is very easy to blowout the highlights past the point of no return.

In video, to deal with the high compression we have, it is generally desirable to shoot with a flat or log profile which basically condenses the brightness values in a smaller range toward the middle of the histogram and we can expand this back out in post processing to get the full dynamic range without losing detail.

In my response to the OPs question, I was guessing that he had less experience with exposing these situations. I also was thinking that fog will have considerable highlights and lots of detail in the highlights that he wouldn't want to lose and thus better to err on the side of underexposure. That said, of course this could be taken too far. If the exposure is pushed too dark, then all of the luminance values will be pushed into the lower half of the histogram. In this case if you try to "lift" the details out of the low midtones you are likely to get significant banding in the image and it'll look awful. In saying what I did I was thinking about a situation where you are perhaps choosing an ND16 or ND32 filter (to maintain 1/60 shutter speed, let's say). If the ND16 was tending to overexpose the image and the ND32 was tending to underexpose some, I'd choose the ND32 to avoid any chance of losing the highlight detail.

I hope this makes sense.

 

[Yoshizakura]

A word of advise for anyone new to shooting video; determine the quality and frame rate and then set optimal shutter speed to 2x the frame rate. Control your light using ND Filters and ISO setting. The unfortunate thing about the Mavic is that you can't really get any usable footage with any frame rate higher than 30FPS so you're going to capture your smoothest video with a shutter speed of 48 or 60. With the shutter speed that low you'll have trouble maintaining that 180 degree shutter rule.

I also suggest turning on the histogram and using it as the sole resource for what your videos exposure is. Far left is the shadow data and far right is the highlight data. Ideally you don't want either level to be up against side or clipped at the top. This way you have some room to work with the file in your post production. I trust my histogram (for exposure) more than I trust my own eyes. Short of having a light meter, you're going to have to get out there and run a few test flights to see which settings will work best for the way you want to capture the fog.

Fog can exist in various light levels so that's why you'll have to pay attention to your exposure via the histogram.

I'd love to say I understood this but I'm afraid I don't. Can't we just shoot default? I understand stills photography but filming is new to me and confusing

 

[DodgeP]

I'd love to say I understood this but I'm afraid I don't. Can't we just shoot default? I understand stills photography but filming is new to me and confusing

If you're familiar with digital photography you may be familiar with reading a histogram and zebras. My opinion is; turn on your historgram and zebras and trust what they're telling you. Auto may not be the best opinion simply because fog is various shades of white and grey and depending on where you fly through the fog your exposure and possibly white balance could be changing all the time.

 

[sdharris]

All great advice here regarding exposure and to get the best out of the camera.

But I will say in my experience if you want to just fly with the camera set to full auto and leave the sensors on you can. I took a walk with the family a few weeks back and between 0 and 200 feet it was light wispy fog, over about 250 feet there was thick fog and the Mavic coped fine. Compared with a Yuneec, DJI products have great metering and are able to produce great results in all sorts of environments.