How can I take good pictures of my reef tankPosted on Sunday, November 22nd, 2009 at 1:50 pm
I wanted to write a tutorial about taking beautiful pictures of reef tanks. Let me start by saying that it’s not as hard as some people make it out to be. Nowadays, cameras have come so far, that you can take wonderful pictures of your reef tank and it’s inhabitants, even with a point and shoot camera. I also want to say up front, that in today’s age of digital photography, my first advice for taking better pictures is TAKE MORE PICTURES. You don’t have to wait for these to develop or printed, and you can check them and shoot again all day long; so shoot away. Ok, we’ll start with some basic photography concepts.
The goal of a good photographer is to achieve good exposure. Exposure is a product of 3 main factors: shutter speed, aperture, and ISO. These components determine how much light is getting to the film (in traditional cameras) or sensor (in digital cameras). Good exposure is achieved when the desired amount of light hits the film/sensor. Let’s look at each components individually first, and then we will look at how they interact with each other.
Shutter speed simply refers to the amount of time the camera’s shutter stays open when you take a picture. Depending on your camera, shutter speed can vary from a thousandth or a second to a few minutes. The longer the shutter stays open, the more light hits the film/sensor. A shutter speed of 1 second lets in twice the amount of light as would a 1/2 second shutter speed. Shutter speed may also effect the sharpness of a photo, especially when a camera is hand-held, or the subject (ex. fish) is moving. Your fish, for example, don’t exactly wait for you to take the picture. If your shutter is open for a whole second, it will record the fish’s movement and you will get a blurry photo. A short shutter speed (maximum of 125th of a second) is my recommendation for shooting a moving subject. If a camera is held by hand, you must take into account your movement as well. Even the slightest movement can create a blurry photo. Ideally, you want to shoot with the shortest shutter speed possible when shooting a moving subject.
So why don’t I shoot at a really short shutter speed you say. Well, because 1/500th of a second, may not allow enough light into your camera, to get a good exposure. Let’s move on.
Aperture (f stop)
Aperture, refers to the size of the opening in your lens. A large aperture means that the opening is large, and more light will go through the lens. A small aperture means that the opening is small, and less light will get through the lens. Aperture, or f-stops, are given a number, for example 2.8, 4, 5.6, 8, 11, 16, 22. The amount of light doubles or halves as you go up one “stop” or down one “stop”. The confusing part is this: a small f-stop (ex. 2.8) means a large opening, while a larger f-stop (ex. 22) means small opening. I’m not going to go into explaining why that is (it has to do with f-stop being a ratio), just remember that as the numbers get bigger, the opening gets smaller. The amount of light that enters the lens also determines something called Depth of Field. Depth of field refers to the are “front to back” that is in focus in your photo. The higher the f-stop, the more “in focus” your picture is. A low f-stop (ex. 2.8) allows more light it, but will have less of your photo in focus. A high f-stop (ex. 22) will let in less light, but will have more of your photo in focus. I like to draw the analogy to squinting. When you can’t see something well, you squint. By squinting, you are making the opening smaller (higher f-stop), and making more things in focus. Remember, with depth of field, we are talking about focus in terms of front to back,. (I’ll add a few photos soon).
ISO or Film Speed
Film Speed (ISO) is simply a measurement of how sensitive the film, or camera sensor is to light. The larger the ISO, the more sensitive it is. The more sensitive the sensor/film is, the less light is needed to achieve the right exposure. An ISO of 100 will need 2x the amount of light as an ISO of 200, to get the same “brightness”. Why not just shoot at the highest ISO your camera lets you? Well, as the ISO get’s higher, your photos will become more grainy. So as a rule, you want to shoot at the lowest ISO you can. The better your camera is, the higher ISO you can shoot at, and still get photos that are not grainy.
Fill the Glass Analogy
So what does it all mean? I like to look at exposure as a glass of water. Let’s look at a glass of water as a representation of a good exposure. You need enough water (light) to fill the glass, in order to achieve the correct exposure. So, the length of time you pour water is the shutter speed, and the diameter of your hose is the aperture. If you were pouring water into a glass, and were using a small hose (aperture), you would need to pour it in for a longer period of time (shutter speed) in order to fill it. If you were using a large diameter hose, you would fill that glass in less time. Therefore, as the diameter of your hose gets bigger, you need less time to fill the glass. As the diameter of your hose gets smaller, you need more time to fill the glass. Within reason, any combination of shutter speed and aperture that yields the correct amount of light, will result in a good exposure.
DON’T USE A FLASH!! (sometimes you can, but try not to)
White Balance for a Reef Aquarium
Ok, so I can take, nice, sharp pictures, but the corals don’t look like they do in real life…they are really blue…why? The answer is white balance (or color balance; same thing). White balance simply means that white will look white in your pictures. You camera will most likely have different settings for different types of light (sunlight, fluorescent, auto, etc) referring do different light “temperatures”. In the reef keeping hobby, we are all quite aware of how our tanks look under 10K lighting vs 20K bulbs. The problem is that our camera has no idea what’s going on, and because we normally use lighting that is more “blue” than natural light, the photos come out blue. Our eyes and brain are incredible, and therefore can adjust for this discrepancy, but our cameras need a little help.
To the rescue comes “custom white balance”. This is as simple as telling the camera “this is what white looks like under this lighting conditions”; nothing more. Most new cameras will have a custom white balance setting. The procedure for each camera may differ slightly, but basically, you need to set a custom white balance, while you take a picture of something white inside your tank. This let’s the camera (sensor) re-calibrate the colors based on what you just told it white is. I normally do this by putting a white piece of PVC in then going to “set custom white balance”. I can then save that setting and use it in the future. It is important to remember that your reef tank lighting temperature will differ when you have your metal halides and T5, just T5s, just metal halides, etc.
Please remember to clean your glass either earlier in the day, or the day before you want to take pictures. This will ensure that you don’t get Coraline spots in your photos.Turn off all pumps and powerheads, so that any floating particles stay still, your corals are not swaying in the current, and your fish come out to see what’s going on.
When taking Full Tank Shots (FTS) make sure that no lights, windows, etc are reflecting off your your tank. Wearing dark clothing will ensure that YOU don’t create a reflection. Turn off the room lights, close shutters and curtains.
Try to stay as still as possible. Using a tri-pod is always a good idea for macro shots and full tank shots, but bracing yourself on a stool or any nearby object will greatly help when holding the camera.
I hope this is helpful for all you reef hobbyists. Please comment below with any questions and suggestions. I will be adding some articles about selecting a camera for reef photography, as well as more advanced tutorials, shortly.