There are so many advances in camera and underwater housing these days it can be a bit overwhelming trying to stay current with technology and to find a camera that suits you. There are many options whether you are looking for a compact camera or DSLR. I can't tell you which camera to buy. I hope I can help you to sift through the jargon and work out what type of camera is best suited to your needs.
Ask yourself what sort of photos you want to make, and also what your budget is. Think about what you want to be doing now, but also about what you expect in the future. Many people want a camera they can grow with. This means choosing something that is easy to learn with, but that will also adapt to your anticipated increasing skill level in the future.
If you really want to progress with your creativity in photography there are a number of compact cameras that allow you to shoot fully auto or fully manual and everything in between. This gives you plenty of range learn and slowly add extras such as strobes, without outgrowing your camera too fast and having to start the whole process again and the expense of upgrading to a better system.
Do you prefer shooting wide-angle or macro? Beginners often find macro subjects easier to shoot as they don’t tend to move very fast and can often be shot quite well with natural light or the built-in camera flash. Many compact cameras on the market can make beautiful images, especially if you are shooting macro. This means you can start slowly and build up equipment like strobes as you build confidence and skills.
There are advantages and disadvantages to shooting with both compact cameras and DSLRs. DSLRs have a broader dynamic range. Dynamic range is the difference between the brightest and the darkest parts of the picture. Because DSLRs have bigger sensors they can capture a much greater range of colours, and greater detail in the highlights and shadows. They produce less grainy images in low light and consequently better quality images.
They also have much more data in each image they produce. The images are bigger – have more pixels, and therefore detail, but that also means bigger file sizes. DSLR cameras can shoot in a RAW format, which not all compact cameras are able to do. This makes it easier to recover blown out highlights and blocked shadows in post-production and will give you much better details and colours when you adjust your pictures. Check this first in your camera’s specifications. There have been so many technical advances in compact cameras in the last few years that many of them actually offer the ability to shoot in RAW.
Because DSLR cameras use interchangeable lenses you have a tool which is designed for a specific job. That means you can get sharper closer images for macro, or better colour (you can get closer with a wide-angle lens and still fit everything in your frame) with a wide angle or even fisheye lens. Whereas on land having the ability to change your lens depending on the situation can be an advantage, this has the disadvantage of needing to select your lens before the dive. This can be limiting in what you can shoot. Although it is possible to shoot some macro subjects with a wide-angle lens (called close-focus wide-angle) you will not be able to capture really tiny creatures such as hairy shrimp. Also you can shoot some wide angle subjects with a macro lens (such as sharks), you will simply get some portion of the fish such as it’s eye or fin, or the pattern of its skin. These can be interesting shots and it is fun to experiment, but by choosing a DSLR you may find you sometimes have the wrong tool for the job at hand.
You don’t use interchangeable lenses on a compact camera. However, depending on which housing you select you may be able to get wet lenses or diopters (such as the subsee) that will enhance their wide-angle or macro capabilities respectively. You can carry them in your BCD pocket and change them on the dive as your subjects change, giving you much greater flexibility.
DSLRs have much more flexibility in their settings, with generally a much wider range than compact cameras for things such as aperture, shutter speed and ISO. You can create more artistic effects by manipulating these settings.
DSLR’s are also bigger and heavier than compact cameras. This means it takes up more space in your luggage when you travel, and you may even have to pay excess baggage charges for your camera equipment. I feel like I am moving house every time I go on a shoot with multiple pelican cases! You can just put your compact camera in your carry on.
Not only are they more difficult to transport on land, but they also have a much greater impact on how you dive. A bigger heavier camera makes bigger changes to your buoyancy. It also causes a lot more drag through the water, and it can be very difficult to cope with a strong current when you are pushing a huge rig around. This can even lead to increased air consumption, exhaustion, and in extreme conditions carbon dioxide build-up which means you might end up having to abort the dive.
Having the highest mega-pixels is a selling point used by many camera manufacturers. We are fooled into thinking more must be better. But this is not always an advantage. More pixels mean more noise (graininess). Some manufacturers have even recently downgraded the number of megapixels produced by their cameras, and the quality has consequently improved. With a relatively low 10-14 megapixel range you should be able to produce good quality images.
Another thing you might want to consider is the battery life of the camera. Obviously we can’t change the battery underwater. Make sure you select a camera that has a battery that will last for the entire dive.
Also think about the subjects you like to shoot and how this could be affected by lighting and camera housing configurations. If you like to shoot wide-angle you may need a dome port (for a DSLR camera) or a removable wet lens for a compact camera. This could potentially obscure the internal flash, which means you might want to invest in a strobe (or two). This is probably not such an issue if you are only shooting macro.
Think about whether you might want to invest in strobes for the future. There are a lot of different kinds out there, and even specialised strobes such as snoots for macro photography.
A good intermediate option could be choosing a mirrorless camera. They still use interchangeable lenses like DSLRs. This means they have more flexibility and creative advantages in being able to manipulate settings over a compact camera. Additionally, they don’t use the bulky complicated mirror system that DSLRs do. This means they are much smaller and lighter.
However, mirrorless cameras don’t have an optical viewfinder (the eye piece you look through), have fewer lens choices and more streamlined controls than a DSLR. The first two of these issues might not be such a concern as it would be on land as it is rare that you would see anyone shooting underwater with a portrait or telephoto lens for example. The go-to lenses for underwater tend to be fisheye (10mm), wide-angle zoom, and a fixed focal length macro lens.
While DSLRs are “full-frame” which is the equivalent of shooting on 35mm film, many mirrorless cameras have a smaller sensor. Consequently, compared to mirrorless cameras a DSLR may produce better quality images. If you are willing to spend a bit more on a mirrorless camera for a bigger sensor similar to a DSLR they can produce images of very high quality and perform just as well in low light.
In practical terms this means that the frame size is approximately one third smaller and therefore to achieve the same results you would use a lens with a smaller focal length. So while I use a 100mm macro lens on my full frame Canon 5D III, to achieve the same size of the subject in the frame on a mirrorless camera I would shoot with a 60mm lens.
Auto focus is also different on DSLR and mirrorless cameras. If you want to shoot video, the mirrorless cameras are actually often slightly better with autofocus on live view (using the LCD). A DSLR will be slower to focus as the mirror system is no longer available. With my DSLR there is no continuous focus for video, which makes keeping a moving subject in focus almost impossible. However, when looking through the optical viewfinder for photography the autofocus is faster on a DSLR.
Compact mirrorless cameras win easily when it comes to continuous shooting as they don’t have the complex system of lifting up and down the mirror every time the shutter fires. The question is, how relevant is this to underwater photography? I never use it underwater but you may want it on land (to take multiple shots of a fast moving subject such as an athlete). If you want to be able to use your camera both on land and in the water this might be something to consider.
DSLRs tend to have much better battery life than compact or mirrorless cameras, simply because there is space to fit a bigger battery inside a bigger camera. In addition, when you shoot through the optical viewfinder on a DSLR it uses very little battery in comparison to the live view on the LCD which you are forced to use on a mirrorless camera. When you are shooting underwater this is an important consideration since you can’t change the battery on a dive. There is nothing more frustrating than getting halfway through your dive and the battery dying. You can almost guarantee that is when the dugong will show up and do a twirl!
Price-wise they start at about the same amount, but DSLRs go much higher. However, if you want a “fully featured” camera, a DSLR will give you much more for your money when shooting primarily photos (as opposed to video). But the gap between mirrorless cameras and DSLRs is getting much smaller and it is definitely worth spending some time researching what is right for you.
DSLRs produce beautiful high quality images, but they are also a big financial investment. And it’s not just the camera – usually the housing is even more pricey. With interchangeable lenses it means you also need separate ports for different lenses.
Make sure you can see the LCD of the camera easily in the housing and that you can access everything in the menu system. Some camera housings, especially the smaller ones for compact cameras, will not have buttons for everything on the camera. There is sometimes an alternative which you need to check in the manual for use in the housing. For example, there could be assignable buttons which you can change between different settings such as aperture, shutter speed, exposure and ISO. Some cameras have a custom button which can work as a short cut for things like white balance. This will make it much quicker to change settings in the housing.
Also think about what depths you will be going to. The most life and light are at shallow depths. If you are a technical diver like me, you might want to take your camera deeper than normal recreational depths. Make sure the camera housing you choose for your camera is rated to go that deep.
You might want to consider a housing that is a different brand to your camera. For example, although Canon makes housings for its compact ranges, Ikelite, Nauticam, Aquatica and many other brands may also make a housing for the camera you selected. These are usually sturdier, rated to deeper depths, and less likely to have problems with buttons sticking that small compacts often suffer from.
Do your research before making a final decision and make sure you choose the camera and housing that is right for you. There are lots of ways of finding information before making a choice. There are many photography forums such as Wetpixel.com where you can find reviews, or FaceBook groups dedicated to underwater photography. There are plenty of vloggers on YouTube who offer reviews, information and tutorials about lots of different brands and types of camera.
With the growth of the internet and social media there is a wealth of information available which will help you make a well informed choice. Ultimately, although features are important, you want to choose the camera you feel most comfortable using. Try out a few in a shop, or if you have a few friends who are photographers ask to try out their cameras, before you buy.