Since the release of the first digital Hero camera in 2006, GoPro cameras have become more and more popular internationally as the go-to camera for capturing any extreme sport from the wearer’s point of view. A decent waterproof depth rating meant that users could also take these cameras along on dives, and although this was not the original intention for the camera, GoPro quickly saw it’s potential and started developing a range of products to support this, starting with the dive housing for the Hero2 which originally came out with a domed lens which would cause vignetting under water. The Hero3 then later followed suite and came out with a flat port as standard, meaning that no additional hardware would be required to take great underwater footage. Although this is partially true, the software was not updated to cater for underwater shooting, thus meaning that the white balance would have a hard time keeping up, especially during deep dives. There are however a few things you can do in order to make full use of the underwater potential of this great little camera, and I’ll be covering them in 7 summarised tips split between hardware and software requirements. For this guide, we will be discussing the capabilities of the Hero 3 Black:
1. LCD BACPAC
Unlike so many of it’s competitors, the GoPro does not come standard with an LCD screen. Although not a problem when mounted on the wearers head, this particular little piece of equipment is perhaps the most important accessory to get when using your GoPro to shoot underwater footage. It will allow you to frame your shots as well as manage the white balance and ISO effectively between shots. Keep in mind that the added LCD BacPac will have a negative impact on your battery life, so if you intend on regularly doing more than one dive per day, you might want to consider getting a spare battery and anti-fog strips as well. These will keep condensation at bay when going through temperature changes associated with consecutive dives.
2. TWO HANDLE TRAY
No one wants to watch shaky, bobbing or swaying video, and although this can be partially fixed in post editing, it does take it’s toll on your overall video quality. The smoother your shots, the less video repair has to be done in post which means that you will maintain the full resolution and bit rate of the orginal. Two handles allows maximum stability by using both hands, and also allows you to easily follow a subject with one hand as well as hand your rig to another diver with ease. Lastly, two handles support two arms, which brings us to the next requirement.
3. ARMS & LIGHTS
There are many solutions to combat the effects of the camera’s failing white balance when it comes to shooting under water. One of the most common solutions is the use of a red filter which combats the lack of red colour at depth by adding this colour manually. These are however not as generic as one would think, as different levels of red colour exists at different depths, and colours other than red is lost at greater depths which would mean that a mere “generic” red filter would no longer do the job when diving wrecks at depth for instance. Furthermore, any filter that is applied to your camera will have a negative impact on the amount of light that reaches the sensor. The camera will try and cater for this by upping the ISO, which in turn might lead to grainy video. Bottom line, red filters are an affordable means to an end and will not necessarily always result in the best quality video. As a matter of fact, a talented video editor might have much more success at fixing bad white balance in post than a red filter could ever do.
The alternative is making use of underwater video lights. These will effectively increase the amount of light reaching the sensor, thus lowering the ISO for great quality video while also adding much needed natural white light to enable the camera successfully manage it’s white balance resulting in blue waters and colourful reefs and marine life, not to mention add the ability to light up dark corners, caves and crevasses which is otherwise impossible. Having a video light mounted on each arm ensures that subjects are adequately lit from both angles, minimising unwanted shadows and backscatter. The trade off however is that video lights are useless unless they have an object to illuminate, so if you’re just shooting open water or bigger scenes, they will have little to no effect.
For this reason, you would ideally need a combination of both, having video lights for reef shots and both shallow and deep filters for the more open water shots (See Backscatter Flip 3.1)
The GoPro allows for a range of frame rates which are linked to the resolution, i.e. a higher resolution will have a lower maximum frame rate. When shooting any form of video, the effects of a lower frame rate become more and more visible as you get closer to the subject, thus for long distance shots you might be able to get away with a lower frame rate, whereas close-ups will be more prone to blur at low frame rates. The safest bet would be to shoot everything at the highest possible frame rate to ensure that you have smooth video all around. That being said however, please keep in mind that the higher the frame rate, the less time each frame is exposed to light meaning that unless there is more than enough light on the subject, the camera will hike up the ISO on high frame rates in an attempt to alleviate this, once again potentially leading to video noise. This is however unlikely to be a problem when making use of video lights and will be more common when using the cheap red filter alternative. Regardless, the likelihood of shooting close-ups while diving is very high and ideally you would not want to end up with two different frame rates as this will later become a problem requiring fps conversion when trying to add both clips together in post. A frame rate of 48-60 fps will be sufficient as a shooting standard.
The Hero 3 Black employs a 1/2.3″ 4:3 4K (4000×3000) CMOS sensor at a fixed aperture of f/2.8. Ideally, 4K would be the best resolution to use since it would make use of the entire surface area of the sensor, thus allowing for maximum utilisation of the available light. Unfortunately, the processor cannot process the total amount of pixels fast enough to allow for a decent frame rate which is why we have to go for a lower resolution for the sake of smooth video. That being said, the Hero3 Black will give you two obvious options when it comes to picking a resolution that conforms to the above recommended frame rates: Either 1080p or 1440p. Whichever you take will be greatly dependent on whether you are concerned by the aspect ratio of your result, and how much work you’re willing to do in post. While 1080p has an aspect ratio of 16:9, 1440p has a ratio of 4:3 (being 1920×1440 compared to 1920×1080). In a sense this is great since you’ll end up capturing more scenery for very little sacrifice in terms of frame rate (50 vs 48 on PAL), but the problem is that just about every monitor currently produced makes use of an aspect ratio of 16:9. This would mean that if you display your unedited 1440p video on a conventional full HD monitor, the monitor will automatically letterbox the output (adding black bars on the sides) and since it cannot display any more than 1080 pixels vertically, the monitor will automatically scale down your video meaning that the resulting video displayed will have a much lower resolution than that of the raw video. For this reason, unless you’re prepared to crop back down 16:9 in post, I recommend sticking to good old 1080p-50/60 until such time as GoPro is able to shoot 2.7K at atleast 48 frames per second.
6. FIELD OF VIEW (FOV)
The camera will provide you with three angle options at 1080p being wide, medium, and narrow. This may seem trivial, at first, but keep in mind the way the different angles are achieved: The GoPro has a fixed zoom, fixed lens and fixed aperture. In order to provide different angles, the camera will use variable percentages of the available pixels. On a narrow setting, it will only use the middle 1920×1080 pixels of the sensor, whereas on wide, it will use 3840×2160 and then scale it back to 1080p, meaning that every resulting pixel will be determined by the surrounding 3 giving you much better detail and greater light sensitivity in comparison to narrow 1080p. In other words, 1080p on wide will be scaled 4K (100% of sensor surface) and medium will be scaled 2K (75% of sensor surface), while no scaling is applied to narrow 1080p (50% of sensor surface). All this taken into consideration, you would typically look at using either wide or medium (never narrow), depending on how much fish-eye you’re willing to tolerate. Remember that since the GoPro is fitted with a wide angle lens, the wider the field of view, the higher the amount of horizon distortion you’ll see when shooting downwards or upwards at an angle. This usually prompts me to stick to medium, but the downfall is that when applying anti-shake in post, the video is slightly cropped. This cropping on a medium field of view leaves an inadequate amount of the original frame in shot, so knowing that I’ll be making use of anti-shake, I shoot everything in wide angle so that when it is applied, the resulting image would still allow for a decent amount of the original frame to be in shot.
If you’re experienced at video editing and willing to spend a little more time in post of the sake of the best possible results, you will benefit from enabling Protune which unlocks a few additional settings like manual white balance and exposure. When using Protune for underwater shots, set the white balance to Cam RAW and leave exposure on Default (The Hero3+Black has additional settings like Sharpness, ISO and Colour as well). When Protune is turned on, your camera will capture the maximum possible amount of information at a very high bitrate allowing a lot of flexibility in post.
The above is what I have personally experienced as being relevant points of focus when it comes to shooting great underwater video. It is by no means all-encompassing, and no amount of settings and gadgets can do as much for your results as experience. Be sure to tag your camera along on every dive, play around with the settings and compare results until you find that sweet spot where your results require minimal work in post while looking great. Editing a new video is only fun for a while and being stuck with bland, inadequately lit video can be very frustrating especially if you’re anxious to share your results with your friends and dive buddies. We may dive the same site every day for a month and see something different every day, and that’s why it’s so important to take the time to get to know your camera and ensure that you bring back guaranteed exceptional video from every dive.