There are some snorkeling camera features that really make better pictures. Read below to understand what things to look for in a snorkel camera, and to understand a little bit more about how to use your camera. You will find in my camera recommendations that I mention a lot of these things.
In my camera reviews you may see me get excited by a new camera with a "fast" lens. What does that mean and why is a fast lens valuable for snorkeling photography?
A lens has an aperture in it, like your eye. It opens and closes allowing more or less light to hit the sensor inside the camera. A fast lens, can allow in more light than a slow lens.
Stop Blurry Pictures Of Fish
Why is letting in more light good? Letting more light into the camera allows the camera to have a faster shutter speed. And the shutter speed is what stops motion, either fish motion, or your hand motion, so you don't get a blurry fish, or a blurry picture. And sometimes you need that, because the light can be low at times when snorkeling.
With Aperture Higher Is Slower
Aperture settings are called F-Stops. An F2.8 lens, is faster than a higher numbered F4 lens. For example my Canon S90 has a F2.0 lens. That is how much light it can let in, at least when it is at it's wide angle zoom setting. A zoom lens will get slower as you zoom it out. The S90 is only F4.9 when the lens is zoomed fully out. That is why when you look at the front of a lens it will have two numbers, like F2.0-4.9. Since I shoot at wide angle for most shots the first number is the one I am most interested in.
Shutter Speeds Are About Time
Just so you know, shutter speeds are a measurement of time. So a faster shutter speed lets in less light. A 1s (one second) shutter speed lets in way more light than 1/250s (two hundred fiftieths of a second). For snorkeling, faster shutter speeds are nearly always more useful (since you can't use a tripod).
What About Depth Of Field?
If you have enough light that you can reduce your aperture (say from F2.8 to F5.6), you may want to, so that you have more depth of field. Depth of field is how much is in focus from front to back within your picture. Reducing your aperture increases depth of field. If you are shooting with a wide angle lens, on a compact camera, you only need to stop it down a little bit for everything to be in focus from front to back. On some cameras stopping down your lens some may also give you sharper pictures, particularly in the corners.
Shutter For Controlling Motion - Aperture For Depth Of Field
Just remember, the shutter controls stopping motion, and the aperture controls depth of field. When you increase one, you have to decrease the other, so that you maintain a correct exposure.
ISO referrs to how sensitive your sensor is to light. If you don't have enough light, and you can't open up your aperture anymore, or decrease your shutter speed, you can increase your ISO. Higher numbers are more sensitive. Increasing your ISO from 100 to 400, has a similar effect as opening your lens up a few f-stops. But just like in the days of film, higher ISO decreases the quality of the picture. With film, when you went from ISO100 to ISO800, your picture got very grainy. With digital cameras it creates noise, which is similar. And the camera tries to compensate for this noise by using software to blurr this noise together, decreasing details.
So having a camera with good high ISO capability is valuable. It is sort of like having a fast lens, in that it can help you increase your shutter speeds and stop motion.
Image stabilization is another feature that helps make sharper pictures. It is a mechanical process that adjusts for vibration in the camera. With a standard lens, you can hand hold a camera at a shutter speed of about 1/60th of a second, and you will probably get a sharp image. Image stabilization can allow you to take up to three or four stops slower of a shutter speed, depending on how good it is. So you may be able to handhold down to around 1/15th of a second.
But that only helps with hand motion. If a fish is moving, it won't stop that motion. So image stabilization is only so helpful with snorkeling photography. Still it is worth having.
Read more about the different types of Image Stabilization here.
I almost never use a flash with snorkeling photography. Yet most underwater photography guides you read will tell you have to have a big external flash. That advice is for divers, for whom a big external flash is a necessity, for two reasons. One, they are deeper underwater, and there is less light. Two, because of the depth they loose a great amount of color in their subjects.
The problem with a flash is that if it is close to your lens, the light from it will reflect off all the little particles in the water, creating spots all over your picture. This is called backscatter, and it is unattractive and distracting. And that pretty much rules out using a flash that is built into your camera body, like on most compacts. That means you have to use a separate flash, and move it a good distance away from your lens, so the light comes in from an angle. This is done by attaching a long arm to your camera housing. Suddenly you are talking about a big contraption to be snorkeling with. I personally am unwilling to do it.
For a snorkeler it is best to have a camera with a fast lens, and good high ISO performance, and not use a flash at all. There is plenty of light in the top 20 feet of water. My recommendation is to turn off your flash.
The rare circumstances for when I will turn on a flash is when taking pictures under ledges where it is dark, or if I am close to my subject when night snorkeling, although flashlights provide most of the light at night.
Another thing to look for on a camera is how much shutter lag it has. How long once you push the button does it take to actually take the picture? On some compact cameras shutter lag is a real problem. You hit the button, and the fish is gone before the camera actually takes the shot. Getting a fast shooting camera is important for good snorkeling pictures.
Also, being able to shoot many pictures per second can be handy, to try and capture some fish action. High frames per second (FPS) is a valuable feature.
Focus speed is also important. If it takes forever to focus on a fish, it will be long gone.
A wide angle lens is very desirable underwater. Getting close to your subject is the goal. The main reason for this is because you want to shoot through as little water as possible between you and your subject. Water acts like a thick dirty filter, reducing color.
Wouldn't a long zoom lens be good, so you don't have to be as close to the fish, but still have it big in the picture? Sounds good, but unfortunately no. Normally when you try taking pictures when snorkeling with a zoomed out lens, say to 100mm or more, you will be shooting through too much water. The color and sharpness will be very poor. Also, a zoomed out lens reduces light, because as mentioned above it will have a smaller aperture value when zoomed. That means slower shutter speeds, which means you are much more likely to get a blurry picture.
Another thing to know is that as your lens zooms out, you have to increase your shutter speed to stop hand motion from making blurry pictures. While you can easily handhold at 28mm with a shutter speed of 1/60th of a second, at 120mm you will need a shutter speed of at least 1/125s to stop camera shake. This becomes a problem if there is not enough light.
There is one other problem with using a lens zoomed out. It is very hard to compose your picture on the screen, because your zoomed lens has a narrow field of view. It is like trying to find something in the distance with binoculars.
For this reason pay more attention to the wide end of the lens when buying a camera. Anywhere from 28mm and wider is useful. And avoid super zoom cameras; in addition to the problems above, they are rarely sharp or fast.
The lens is probably the most important thing on the camera. A sharp lens makes pictures that are crisp, clear, colorful and focused. A cheap lens will give fuzzy, low contrast, pictures. Many waterproof cameras that have tiny little lenses, are not very sharp at all. Or they are sharp in the middle, but are very unsharp at the corners. So, before buying a camera, make sure you read some reviews about how sharp the lens is, corner to corner. Don't just trust that because it is a Nikon, Canon, or Carl Zeiss lens that it will be sharp. Each camera is different.
As you desire to create better pictures, you will see the value of having more control over your camera. Better cameras allow you to control as much or as little as you want. Once you gain a basic understanding of how simple the settings on a camera really are, then you will find that a fully automatic camera gets in the way of what you want. It will actually start to drive you nuts, because you can't get it to do what you want. Fortunately compact cameras with manual controls are becoming more common. At the very least, get a camera that gives you either aperture or shutter priority controls.
Having a nice big screen that is very bright is helpful. Higher resolution also can be nice, for seeing your pictures with more detail. There are a variety of new screens coming out like OLED, that are faster, have more colors, and use less power.
Taking videos can be great fun. I would probably not buy a camera that does not offer full 1080P HD video. Some cameras advertise HD, but it is only 720P.
Here is a quick tip on snorkeling videos; move very slowly when taking a video. Pan your camera much slower than you want. Don't jerk it around looking at this fish and then that one. It will make for a terrible video to watch.
Part of getting good color in your snorkeling pictures is understanding and using your camera's white balance settings. What is important on a camera is that it has at a minimum an underwater white balance setting. And better yet is the ability to set a custom white balance. Before you buy a camera figure out how much button pushing and looking around in menus it takes to adjust your white balance. It is such a commonly used function that it should be easy to access. Read my tips on using white balance here.
Your sensor is like your film in your camera. It senses the light coming through the lens.
The size of your sensor is it's physical dimension. This number is rarely advertised and is different than the megapixels.
A bigger sensor is normally better because it will provide better high ISO performance. The downside to a bigger sensor is that it requires that the lens be bigger also. A compact camera has a small lens, because of a small sensor. A DSLR has a much bigger sensor, and huge lenses comparatively.
Some compact cameras have slightly bigger sensors and are desirable. For example the Canon S95's sensor is 1/1.7", which is a little bigger than most compacts that have 1/2.3" sensors. And mirrorless cameras have much bigger sensors than the S95.
So what are megapixels then? The pixels in your sensor record detail. The more pixels, the more detail. So a compact camera can have a 1/2.3" sized sensor, containing 16 Megapixels, and a DSLR with a huge sensor can also have 16MP. So it sounds great to have lots of megapixels, right? The problem is that the more megapixels you stuff into a sensor, the poorer the high ISO performance. This is particularly true of small sensors.
So, while it sounds good to have 16 or more megapixels in a compact camera, in fact it is generally not so great. Notice that some of the more expensive, professionally oriented cameras like the Canon S95 only have 10MP. That is because they sell those cameras to a more knowledgable crowd. Also, file sizes go up astronomically as the megapixels climb just a little bit. Unless you really want to print a huge picture for your wall, 10MP is plenty for nearly every need.
The thing to take from this is that with compact cameras, don't get focused on having lots of megapixels. There are much more important things.
CMOS vs CCD Sensors
What about the different types of sensors? Lots of cameras now have CMOS sensors. They use less power and they are faster in their operation. They also offer some advantages for video, namely autofocus during HD video. They are not necessarily sharper though.
SD memory cards are the standard for most cameras. But did you know there are different types and speeds of SD cards?
Storage Capacity Types:
Before buying a card for your camera read it's manual and see how big of a card it will take. Some older cameras won't work with and SDHC card. And few cameras will work with an SDXC card. You may also want to check what your card reader in your computer will read, if you access your pictures that way (instead of through a cable to your camera).
The speed of the card is how fast you can write data to it. The number is the minimum speed it will write at, in megabytes per second.
There Are Four Speed Types:
For pictures, a Class 2 is going to work just fine. But for HD video in a compact camera you generally need Class 4 or above (but check your manual).
One other note about SD card speeds. There are a lot of counterfeit SD cards being sold, that advertise they are a brand that they are not, and a speed that they are not, even on Amazon. So read reviews, buy brand names, and you can also download free software that will check the minimum write speed of the card you buy. If it does not meet the standard, return it.
That is most of the stuff that I consider important in snorkeling camera features. It seems like a lot to consider if you are buying a camera. Fortunately when you look through my camera suggestions at the link below you will find that I suggest cameras based on these features, which will make your life easier.