Best way to video fast flashing bright lights

TomN

Hello,

I own a small business selling emergency vehicle lights and sirens to police, fire, and ems personnel. Our product line consists of all of the bright, fast flashing lights that you pull over for when you hear a siren screaming behind you! I purchased a D3100 because I knew that it could shoot video, but I'm not sure of the best way or best settings to use for shooting demonstration or installation videos of our lights. Every time I try to shoot a video, the background gets darker/lighter sporadically, there's a huge blur of light when it flashes, or I can't capture the true color of the LEDs, etc.

Here is a sample of a video I made for reference:
Product Demo: http://m.youtube.com/watch?v=tkRiNekuXbY
Vehicle Install: http://m.youtube.com/watch?v=GpxGEjX3ee0

Does anyone have any tips for shooting fast flashing bright lights with the D3100?

Thanks in advance!

ohyeahar

Sorry, this is going to be a very long post! I do have settings to recommend. So just skip to that if you don’t want to read!

For whatever reason, Nikon doesn’t really allow full manual control when it comes to shooting video. Even if you’re in Manual mode, the camera will try to override your exposure settings. There are ways to work around this.

Let me start by explaining why your current videos are dimming and brightening sporadically. With the way your camera was set up, it’s constantly metering the scene. If it decides that the scene is over or underexposed, it will automatically adjust the ISO to compensate. So what’s happening is once the your light flashes, the camera thinks the entire scene is overexposed (too bright), so it lowers your ISO (to darken the scene). But in a split second, your light flash is off so the entire scene is now underexposed (too dark), so the camera boosts your ISO (to brighten the scene). But then the light flashes again and all this repeats over and over.

Here’s the limitations of your camera (and most other Nikons, unfortunately):

1. When in Live View, you can’t adjust the aperture. It doesn’t matter if you’re in A (Aperture Priority) or M (Manual) Mode. It’s maddening. The workaround is to set your aperture prior to going into Live View.

2. When in Live View, once you press that red record button, the camera will instantly meter the scene and choose the appropriate aperture-ISO combination to maintain proper video exposure. This means that you can shoot in any of the P, S, A, or M Modes and then select your aperture, shutter speed, and ISO but the camera will still override all your settings. Again, it’s very maddening.

HERE’S WHAT YOU NEED TO DO!
First, it looks like from your two videos that you’ve stabilized the camera (probably with a tripod). That’s good. Do that.
Here’s what I would adjust on the camera:

1. Make sure Auto-ISO is off.

2. Change your Fn button to adjust ISO sensitivity (by default, it changes your camera’s shutter mode to timer).

3. Set the AE-L/AF-L to AE lock (hold).

4. Turn mode dial to A for Aperture Priority Mode (reminder: you should NOT be in Live View yet).

5. Set the aperture by rotating the rear control dial. Judging from the ambient lighting in your two videos, you should just shoot at whatever is the maximum aperture for your lens (i.e. smallest f-number).

6. Set your White Balance. Auto works ok sometimes, but using the appropriate presets often gives better results in terms of color reproduction.

7. If you want, set your Picture Profile. If you’re going to edit the video in post-production, it may be best to choose Neutral. Otherwise, you can just stick with Standard or whatever you feel gives you the best colors.

8. Set your ISO by rotating the rear control dial while holding the Fn button. Watch how the shutter speed setting changes as you adjust the ISO. As always, use the lowest ISO possible, but keep the shutter speed at twice your framerate which means at least 1/50 for 24 or 25 fps and 1/125 for 60fps.

9. Go into Live View mode. I highly suggest pressing your shutter button to take a shot at this point. Not only will the image quality look very much like the video you’re about to shoot so you can make adjustments if necessary, but the photo will also contain the exposure settings so you may refer back to it if needed (e.g., if you want to replicate the same settings).

10. Lock your exposure by pressing the AE/AF Lock button.

11. Finally, press the red button to start recording your video!

(I don’t have any flashing lights to test a video recording with, so I’m not entirely sure about this last point. I think it may be a good idea to underexpose by about 2-stops since you presumably want to show how the flashing lights look with a darker ambient lighting. To do so, adjust your exposure compensation prior to going to step 9.)