Your Eyes are a Miracle, Your Camera is a Machine
(This is lesson 2 in my Learn Photography Series)
The previous lesson started on a dark note. I’ll try to win you back with a compliment. You have beautiful eyes. No, I’m not just saying that so you continue reading my boring camera lessons. I really mean it, and I want to make a point. Your eyes are amazing instruments created through millions of years of evolution. A camera does not come close to the sensitivity and flexibility of your eyes. More importantly, your eyes are connected to the best image processing computer available, a human brain. Your brain adjusts contrast and exposure so quickly that you don’t even notice it happening. Have you ever looked through your eyes and said to yourself, “Hey, this scene could use some more contrast and a saturation boost”? Unfortunately for the beginner, cameras do not record the world the same way as the human eye. To become a photographer you must learn how the camera sees.
Let’s start with a technical term you might have come across while shopping for your camera: dynamic range. What is dynamic range? Dynamic range is the range of what is visible between the darkest black shadow and the brightest white highlight. Your eye can see almost twice as much dynamic range as a digital camera can record. For example, on a sunny, summer afternoon your eye can see details in the shadows beneath a tree and, at the same time, see details in the white puffy clouds in the background. A camera can’t. In that situation, your camera only has enough dynamic range to see inside the shadows or the white puffy clouds, but not both at the same time. Below is an example of a photograph of a bright summer afternoon. This photo contains both areas of highlight (the sky and clouds) and shadow (the people under the tree). When I took this photo my human eye could see details in the shadow, but notice how the camera recorded the scene. The lady and the stroller are almost completely black silhouettes. By looking at this photo can you decipher the color the woman’s hair? I can’t. However, if you were standing next to me when I took this photo you would know it’s brown.
The bottom end of dynamic range is black. At the other end is white highlight. Take a look at the photo below. In this example the brightest parts of the photo have turned white and no detail is visible. This is called over exposure or high-key photography. When I took this photo the sky looked completely blue to my eyes. However, the camera didn’t have enough dynamic range to capture the bright highlights.
The dynamic range of a camera sensor is much smaller than your eyes. If you had to exchange your eyes for two modern digital image sensors you would live in a world of blinding highlights or impenetrable shadows. Walking in the park would become an adventure. You would have to choose between seeing in the shade or seeing in the sun. You can look at this as limited dynamic range as a shortcoming of photography or as an invitation to creativity.
Many of my photos use deep black shadows to create drama.
Or, I’ll use pure white over exposed areas to simulate a level of brightness no man-made medium can recreate. In later lessons I’ll show you how to control these effects.
In addition to limited dynamic range, another major difference between your eyes and your camera is the perception of color temperature. Every light source has a different color temperature (color cast created by the frequency of the light emitted from the source). Incandescent lights cast a yellow-orange light. Florescent lights give off a blue-green glow. The sun is mostly neutral, maybe a little yellow. And, the light in open shade is blue. Our world is full of color casts but we rarely notice them because our eyes combined with our brains do a fantastic job eliminating color casts. When was the last time you walked into a florescent lit store and said to yourself, “Man, these lights have a horrible blue cast?” Probably never. Your eyes adjust for color casts instantly, and they can even adjust for multiple casts in the same viewing area. Digital cameras handle color temperature much less gracefully than your eyes. To mitigate color casts your camera uses a setting called “white balance”. Your camera’s white balance can be set to auto, tungsten, sunny, cloudy, florescent, ect. These settings will eliminate a color cast from a standard tungsten or fluorescent bulb, but they don’t work well if your light source is anything other than what your camera’s engineers called average. That means almost every non -standard light source is going to give you a some amount of color cast. Fortunately there is a great solution to this problem. Shoot in RAW format. When you shoot in RAW you set the white balance in Photoshop or Lightroom. Rather than relying on the rigid in camera white balance presets, you set your white balance via the RAW converter. You can easily tweak the settings and get exactly the right white balance. Sounds complicated, right? Don’t worry – I already wrote a lesson on how to set white balance in Photoshop. Some photographers use color casts for artistic effect. Maybe you like to have color casts in your photos or maybe you like perfect white balance. It’s a matter of taste. For now, as a beginner, all you need to know about white balance and color temperature is your camera sees color temperature and your eyes don’t.
Above is an example of a color cast caused by an artificial light source. Our kitchen is lit with those new florescent light bulbs that try to simulate the warm glow of incandescent bulbs. My camera’s auto white balance can’t figure out the situation and the original photo (the one on the left) is filled with a yellow-orange cast. The photo on the right was quickly corrected in Lightroom. Notice that the white plates are actually white in the corrected photo.
Before I end this lesson I’m going to give you an assignment. The assignment is to play a visual game with yourself called “White Point Black Point”. You can play this game while looking at anything. When I first got into photography I really paid attention to how I saw the world and I came up with my “white point black point” rule. Here is the definition of the white point black point rule: for every scene you view (with a few exceptions) your eye automatically sees the darkest spot as black and the brightest spot as white. What does that mean? No matter what you look at you are going to see the darkest area as complete black and the lightest area as completely white. Your eye is constantly adjusting contrast to its maximum so the the brightest spot of whatever you might be looking at is white and the darkest shadow is black.
Here is a sample of what I am talking about – the cup of ice water is sitting on a glass topped desk and lit by nothing other than window light. I marked the white point and the black point. Now, try it out for yourself. Look around your room and see if you can spot the white point and black point as your gaze moves around. No matter what your field of view you should be able to pick out a white point and black point. Practice picking out the white and black point whenever possible. You can do it when you’re walking the dog, brushing your teeth, or sitting in a boring meeting. Once you’re really good at it you will be able to pick out the black and white point without even thinking about it. It will be second nature. When you are really, really good you’ll be able to pick out the black and white point and know how far apart they are in terms of dynamic range. You’ll know whether a scene will fit inside you’re camera’s limited dynamic range with just one glance. That’s the goal. The next couple lessons will explain exposure so practice finding black and white points for now and get a jump on the competition.
Like every rule my black and white point rule has some exceptions. In certain situations you won’t be able to find a black or white point. There is no black point when you are looking at a polar bear in a snowstorm, and there is no white point in dimly lit areas. I’m typing this at night – in a room lit only by a 40 watt bulb. There is no white point when I look around the bedroom right now. It is important that you learn what type of situations will be missing a white point or black point. Play the “find the white point black point” game a lot. Get good at finding the exceptions to the rule. It will help you later when we start talking about exposure, and it will really help you when we start working in Photoshop and Lightroom.
Above is an example where there is no white point. It was too dark for anything to be white.
The above photo is an example where there are multiple black points, and only one white point.
Are you understanding this? Practice as much as you can. Look for the white point and black point in every photo you see. You should get so good at finding white and black points that you don’t even think about it anymore. You’ll see a photo or a scene and you will know what is the darkest spot and what is the lightest spot without thought. The next couple lessons will explain exposure. If you aren’t understanding these concepts yet, my exposure lessons should clear everything up. Feel free to leave a question or comments. It’s hard to write about abstract concepts. I want to know if I’m getting the point across.Facebook and Instagram. Order prints of the photos featured on this blog by clicking on the image or visit our website at photos4u2c.com Support this site by using one of my links to Amazon.com. Thanks!