Optimal settings for video capture in front of large digital whiteboard

Question

I have a youtube channel and create a lot of technical videos in front of a large Dell monitor which I use as a whiteboard. I used to use my iPhone but switched to Nikon Z50 with a shotgun microphone to get a better quality video (which it is :-)).

As I moved the camera close to me and the whiteboard I can’t get myself and the whiteboard in focus just right.

I did research and I understand this is the depth of field. I already struggled with getting the ISO right since I’m standing in front of a big white screen and found around 1100 is about right which I manage to lock using the AE-L button :-)

I had set the focus to manual as the autofocus didn’t work well in front of the monitor. If I switch the camera to M I can set the ISO and aperture. I understand as I increase the aperture I need to increase ISO as less light gets in.

My question is how I know how to manually focus and what the right f stop is. The camera is about 1 meter from the screen. An example of a video is at https://youtu.be/LWKkva4ksdg where you can see I’m slightly out of focus.

I have 4 lights on me to try and offset the problem of the big white screen as by default it makes me super dark :-) I guess a second question is do I have to set the exposure time and what would I do?

Any pointers would be appreciated.

Thank you.

Answer 1

One problem is that the room you are in is pretty small. One movement of 30 cm is, according to your description, 1/3 of the space, so if you can move further away from the camera that will be an improvement.

Let's think that you have defined your shutter speed, I assume it would be 1/60 s, and the TV present no flickering problem.

The ISO you found to be good for the Screen-Lights combination is 1100, but you do not say the aperture. But that is ok.

Let's make some simple adjustments.

1. Find out what is the maximum ISO where you can live with the resulting noise. Make some tests.

2. You can double the ISO, make it 2200 and close the aperture 1 stop, if you are using f4 you can now use f5.6 If the maximum noise you are willing to use is 4400 you can close the aperture one more stop. f8.

3. Find a middle point between the screen and space you mainly occupy and focus around it. This way you have a compromise between the maximum and the minimum focusing distances.

Do not use the AE lock, simply use all manual settings.

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Overall, the video looks good. If you can add a bit more brightness to the monitor and a bit more light you could close even more the aperture without making the scene darker.

Just move the lights a bit, so you do not cast that much flare on the screen.

Answer 2

I would be using a video frame rate of 24fps and a SS of 1/45; or 30fps at 1/60. The slower SS is meant to prevent recording flickering/banding of the monitor (60hz oscillation). And the SS being 2x the frame rate (180 degree shutter) is meant to record movement more naturally. If you were recording in one of the UHD video modes that might be why the SS was flashing (max frame rate of 30fps and a SS higher than typically desirable).

If you were at 1/100, using 1/45 instead will allow you to stop down another step which will have some small benefit. Your other choice is to frame the scene a bit looser; either by using a wider FL lens, or moving the camera farther away. Or some combination of all three... but you cannot move the camera farther away and zoom in; those two actions cancel each other out.

Your last option is to use some form of manual focus offset (i.e. zone focus, hyper focus, infinity focus)... Your Z50 w/ a 30mm lens at f/16, when focused at a distance of 9ft will give a maximum DOF starting at 4.5ft and extending to infinity.