Shark and Yolanda Red Filter and Ambient Light Filter test clip - Graded in Photo / Video Showcase Posted July 20, 2019 The way to see it if you want to do some tests is that filters on the lens give you around 4 meters benefit on custom white balance. Typically custom white balance works to max 10-11 meters before it maxes out. Some cameras like Olympus can do custom white balance to 14K in some models. Now there are plenty of schooling fish you can’t illuminate with lights and you need to make do with ambient light that are between 10 and 15 meters. This is basically the filter hot spot. In bright scenes 12 meters is also not dark enough to make your lights work well. So the filter helps to resolve that 10-15 meters area ambient light scene that cwb can’t cover and lights are not suited to. If your scene is in the range 0-10 meters the benefit of the filter especially for video on MFT is to avoid apertures beyond f/11 where the lens perform poorly so as by product you also get better sharpness. It really depends on what you are shooting and where but it is nice to have options. For what concerns the ambient light filters this is a more complex topic because you use the lights just for highlights and detail not as main source same goes for strobes but you have much more power there So for experiment purposes you need to be able to understand what shots work with filters and which not and then in case of closer scenes or caves you ca try the ambient light If you start everything altogether you may end up with too much of a challenge If your primary use is still images wrecks around 12-15m are the perfect starting point or large school of fish from the distance Sent from my iPhone using Tapatalk I read that Canon can have extreme manual white balance up to 50K, my personal experience is that it can manual white balance at least down to 25m, but some may find the color unnatural.