GoPro recently released firmware 4 for HERO4 cameras. The new firmware has three interesting features: the ability to lock the shutter speed, extra white balance settings, and new ISO options. All three give you more control over how your HERO4 shoots video (and photos). In this overview I’ll cover only the implications for video shooting.
GoPro added the ability to lock your GoPro’s shutter speed. Before firmware 4 your HERO4 adapted the shutter speed in tandem with the ISO value to the lighting conditions. With the possibility to lock the shutter speed, you now have control over how smooth the motion in your videos flows.
Taking a 2.7K frame size at 48fps as an example, I had the choice to set the shutter speed to Auto (the default), 1/48, 1/96 and 1/192. Under the same lighting conditions and with no other adjustments, the first lock speed equals the frame rate you select. You can’t set your shutter speed to a value lower than the frame rate. The resulting video at 1/48 in my example shows your subject’s movements as blurry trails, while the highest setting shows the moving parts as almost sharply defined objects.
Meanwhile, there are two ISO menu options: ISO Mode and ISO Limit. These two can be set to work in tandem with your preferred shutter speed.
If you change the ISO Mode from Max to Lock, you can set the ISO Limit to a different value than the default of 1600 ISO. Doing this may improve noise, but also contrast levels. It will also potentially cause over- or under-exposure as you can’t change the aperture of the lens.
You may then run into a problem if you don’t have the LCD Touch BacPac as you can’t see how the camera records the scene without. You could of course take with you an external HDMI monitor, such as an Atomos Ninja Blade, Assassin or Flame. In addition to seeing what you’re doing, you will also benefit of the scopes on these devices.
The ISO Mode, when set to Max, will automatically crank up the ISO value until it reaches the ISO Limit when your preferred speed would underexpose your subject. ISO Limit can be set to values starting from 100 to 6400 (200, 400, 800, 1600 and 3200 in-between these).
Finally, the new firmware has extra white balance (WB) settings for finer control. The settings include 3000K, 4000K, 4800K, 5500K, 6000K, and 6500K. As before, you can leave WB set to Auto. If you want to be more accurate, however, you’ll definitely want to change the WB to the closest setting. In this case, you can’t measure the correct WB value unless you have a light meter with you.
Firmware 4 includes a whole slew of other improvements as well. However, these three are the most important ones from a shooting perspective.