Unlike DSLR or dedicated video models, action cameras are far easier to choose and understand. One of the joys of these small devices is that they can produce excellent quality results in their full auto mode even if you have no prior knowledge about video or photography. Other than the positioning or mounting of the camera there seems to be very little else for you to do except press ‘record’ and sooner or later ‘stop.’ However, this does put the camera and the technicians who created it in full control of how it shoots the scene or action that you are filming. the camera is making the decisions for you. this can work pretty well, but does not always produce the best possible results. these cameras are remarkably clever, but alas not intelligent enough to know what it is exactly you are trying to achieve. So with just a little extra knowledge you will be able to choose the right gear, take control of the settings and create video and photos much more to your own design.

A very basic rule is that you get what you pay for. So the more expensive the camera then the more options and add-ons you would expect to be available. At the time of writing, top-of-the-line cameras can cost upwards of £300 (roughly $400) whereas a lower end model may come in at £20–100 ($25–130) and do the required job reasonably well. Let’s look at the basic requirements and discuss additional features which will make your video life far easier and more rewarding.

They will also govern the overall quality of your video. If you don’t already have a camera these are some of the optimal things to look for.

Screen

Most action cameras have a screen so you can see exactly what you are filming. Some do not. As we look to move forward from the basic point-and-shoot way of using action cameras, a screen becomes important. It gives you certainty that all the action is happening within your frame and you are not clipping off anything important. A screen will also show you how your lighting looks. this is especially important when mixing an artificial video light with ambient natural light.

If you have a camera without any sort of screen, I recommend practice and experimentation to get to know exactly what angle your lens covers at any given distance from a subject. Take a shot on land and when you play it back on an independent screen look carefully and note how much of the picture you thought you were taking is actually in frame. Try this for distance shots as well as close-ups.

Depending on what kind of optics your camera has, you will find that underwater the angle of coverage decreases by around one quarter. this is also affected by any additional lens you attach to the outside of your housing — see ‘Accessories: Lenses’ later in this chapter.

Depth rating and construction

Not all action cameras on the market are suitable for diving. Some are only designed to be water resistant, which is good for surface sports such as skiing, cycling or canoeing. Others are fully waterproof but only down to a depth of ten metres, which is good for snorkelling or surfing. For example, the GoPro or the Insta 360.

Be sure you pick a camera (or camera and housing) that has a depth rating suitable for your diving intentions. Most housings are guaranteed down to depths of 30m (100ft) or more, but do be sure and stick to the manufacturer’s recommendation.

Before buying, take a good look at how the housing seals are made and function. Are the closing clips flimsy, or substantial and well-made?  The same question should be asked of the hinges.

Resolution and quality

Many cameras offer video resolution of 720p or 1080p. Most also do 2K and 4K. Starting at the lower end, 720p is ‘High-Definition’ (HD), but is only half the resolution of ‘Full HD’ 1080p. This means 1080p has twice as much image detail and produces images that are twice as large in terms of overall pixel count. However, 1080p also takes up twice as much storage space on your memory card. There then follows the issue of having enough computing power to play back the larger resolution files. This especially applies when filming 4K, which has four times the resolution of 1080p. Although you should be able to play these very ‘high-res’ video files on your TV through your camera, it is not guaranteed that your edit computer will have enough processing power to play the files smoothly.

This becomes particularly noticeable when trying to edit and add effects.

720p has 1,280 pixels displayed across the screen horizontally and 720 pixels down the screen vertically. this gives us 720 horizontal lines on the screen. Before HD came in the normal resolution was 480p, standard definition (SD). SD is now seen as very poor quality.

For most people 720p produces a very high quality image and is excellent for editing and posting e.g. on YouTube. If you are able to process and edit 1080p and have a good speed on your internet, then this is the best option for even greater quality. If you are able to process and edit 2K and 4K then the world is your oyster. In short, film at a resolution that you can edit. Do a test. Film something at 2K then try to play and edit it on your computer. If it works well without any pixelation, breaking up or freezing of the image then try 4K. If the 2K doesn’t work then go lower, try 1080p and so on.

However, although 720p is usable at the time of writing this book, technology moves so fast that it is probable this resolution will no longer be used in the near future and be fully replaced by the higher alternatives.

It is possible to edit 2K and 4K on low specification or old computers by using proxy files and online editing. This copies video files to a lower resolution which your edit software and computer can deal with. then before exporting the final edited sequence or film the proxy files are replaced with the original full resolution versions. But this is for those who are experienced with editing software and is beyond the purposes of this book.

An alternative solution is to film everything in the best possible resolution and archive those files for future use. Meanwhile, convert the files you want to edit now into low resolution copies with video converter software. Free versions can be accessed on the web, for example Any Video Converter and Freemake Video Converter.

When shooting at higher resolutions, the image size can be expanded or increased in the edit without too much noticeable loss of quality. This is particularly useful in re-framing your image or taking part of it to use as a close-up. Somewhere between 25–40% is usually as far as you can go before quality loss starts to become noticeable, but this does depend on the overall standard of the original frame where sharpness, contrast and image density are all factors. Higher resolution images are also better for extracting single frames to print out as photos or to use in publications.

NEXT WEEK:

Part 2 of 6 – Underwater Lighting

Action Camera Underwater Video Basics by Jeff Goodman is available now from DIVEDUP Publications:
https://www.divedup.com/shop/action-camera-underwater-video-basics-the-essential-guide-to-making-underwater-films/

About Jeff Goodman

Jeff is a multiple award-winning freelance TV cameraman/filmmaker and author. Having made both terrestrial and marine films, it is the world’s oceans and their conservation that hold his passion, with over 10,000 dives in his career. Having filmed for international television companies around the world and as author of two books on underwater filming, Jeff is Author/Programme Specialist for the Underwater Action Camera course for the RAID training agency.

Jeff has experienced the rapid advances in technology for diving as well as camera equipment, and has also experienced much of our planet’s marine life. He has witnessed, first-hand, many of the changes that have occurred to the wildlife and environment during that time.

Jeff runs bespoke underwater video and editing workshops for the complete beginner up to the budding professional.