Underwater photography is very similar in many ways to traditional above water photography, which has its own steps in planning a successful shoot. The difference with underwater photography especially when performing it on scuba is that you have additional factors to consider that can affect the execution of your shoot.
Taking your camera underwater requires a lot of preparation and the need of speciality gear designed exactly for your camera. The main thing that you need is a housing and these are not generic in design, they are designed specifically for your camera make/model. Of course if you search on online auction sites, you will find some $20-$50 options that put a bag around your camera and you can hope for the best – but this is a risk that I would not personally take.
The other option to consider is starting out with a smaller, crop censored compact camera that is waterproof to 10 or 20m, that you can start to use to get use to shooting underwater and then build up to a larger DSLR and housing when you have more trading and experience. When I started shooting underwater it was with a compact camera and over the years and 100’s of dives, I have slowly upgraded my gear to now have my ultimate setup.
My setup consists of the following: Nikon D800 FX Body, Nauticam NA-D800II housing, Inon Float Arms, Inon extension arms, Inon Z240 strobes Nauticam extension rings (70mm and 30mm), 8.5″ Dome Port, Macro Port and Diopter (Super Macro Magnification), Go Pro Hero 3, BigBlue magnetic flash off focusing torch, Intova 2500lumen video light and the most important, a tether lead to have it attached to me at all times.
When planning the shoot, especially when using models, depth of the site is a key factor. You need to have the support personnel on hand to be able to administer air (21%) to the model between takes – with the maximum time being the length that the model can comfortable hold their breath and halve this. Support persons need to be qualified dive masters and the model also needs to be a qualified diver – Open Water to 18m and Advanced Open Water to 30m. The deeper you go, the less time you will have as the more air you will use over the same period of time, and you have to follow you dive computer as you must stay within safe limits for no-decompression diving. The maximum time for the entire dive should be 1 hour with a lengthy surface interval in between takes.
The weather is a considerable factor to also consider when planning for the shoot, as if the forecast is to windy, you will end up with the dive and shoot being unable to go ahead due to the conditions. If it has rained in the preceding days prior to the shoot and it is in an estuary or near the shoreline, it could have low visibility in the water and have a green tinge which is unappealing to underwater photography. Also, consider the location of the shoot, if the site is susceptible to large current runs on incoming and outgoing tides, you are going to have limited time to shoot on a slack tide (the one hour at high or low tide). It is very important to be familiar with the dive site and have done a reccy prior to the shoot with the model and the support crew to work out all these factors.
Overcast days also make for a challenge underwater, as the light penetrating from the surface is lack lustre and the imagery will have no pop. Strobes (underwater flash) can only do so much with shaping the light on the subject, for the background to be dancing with light or streaming, there needs to be good sunlight penetrating from above.
The deeper that you go to do the shoot the more light changes. The warmer colours of the light spectrum are filtered out the deeper you go starting with red first, and there is only so much you can do in post. Refer to the rainbow chart below:
White Balance: I have found with white balance that I set the camera’s white balance manually in Kelvin (K). On the surface, daylight is rough 5500K, so
underwater I get the best results from setting the white balance to 7500K from 6m to 12m and then over 12m at 10000K. Some photographers argue that you can do this in post, however I believe you should get your settings as close to possible in camera and not rely on post processing for your adjustments that you can make yourself by being a better photographer.
Shutter Speed: When shooting underwater, just like on land your shutter speed should be at least the same as your focal length – 105mm lens on Full Frame, is 1/125sec if you were on a smaller crop censored camera, double this and shoot at 1/250sec for the same lens – however if using flash, you may be limited to 1/200sec due to the sync with the strobes.
The basic rule is if you are using a full frame body, your shutter speed should be at least equal to your focal length, preferably a little faster, as you the photographer are not anchored and when neutrally buoyant floating like a feather being pushed around by the current. My preference is to shoot in shutter priority mode instead of manual underwater, as you have enough on your mind to keep busy.
Film Speed/ISO: A general rule of thumb that I work by is that ISO100 is great to about 6m. To 12m it is
around ISO320 and then to 18m is around ISO400 and so forth. Anything over ISO1200 is too grainy and unusable, and you should invest in better lighting – constant and flash.
Using a full frame body, your shutter speed should be at least equal to your focal length, preferably a little faster, as you the photographer are not anchored and when neutrally buoyant floating like a feather being pushed around by the current. My preference is to shoot in shutter priority mode instead of manual underwater, as you have enough on your mind to keep busy.
Aperture: Aperture priority is great for macro shooting but not overly practical when shooting a model, as the distance between yourself and the subject is not fixed – as you are both floating. If you are shooting on shutter priority (using example above – 105mm lens at 1/125sec and your aperture has been set to wide open (your lowest f-stop of the lens), your ISO is too low.
When diving, it is important that you are comfortable, and this is done by selecting an appropriate protection underwater in the form of a wetsuit or drysuit, and being weighted correctly so that you are not too heavy (hard to be agile) or too light (can’t get down). Wearing gloves is an optional choice, as you can lose dexterity in the finger tips and not be able to control your camera if the gloves are too thick.
Make sure that your boat skipper and surface support person know what you are doing (your shoot plan) so they can be able to assist you at all times.
When shooting underwater make sure you have a benchmark of what you are trying to achieve so both the model and you know what look is expected, anything else is going in blind and unprepared. Laminating the benchmarks allows you too take them underwater when you can’t easily return to the surface to check them out.
You don’t always need to use strobe and constant light, a silhouette direct into the sun can be a more powerful image than one with light thrown at it. Also when shooting underwater don’t forget to look up, as some of the most beautiful lighting is directly above you and working this in with your model will create some beautiful compositions.