[Part one of the Photography Fundamentals series, be sure to check out all 10 posts!]
The human eye is simply amazing.
Our sensitivity to light allows us to see objects in nearly pitch dark that are a billionth of the luminance they would be in full sunlight.
We have yet to produce a piece of technology that can render the full spectrum of colors our eyes can see.
Photographs have always been a reproduction of the lightness and darkness the eye can see (color was added to the equation later). The scientific measurement of how light or dark something is is called luminous intensity. We’ll just call it luminance.
Luminance: The measurement of how light or dark something is.
As a photographer you have the power to use luminance for good, or for awesome. What you will likely be more concerned with is the total amount of luminance you allow onto your sensor (or film if you’re old school and extra cool), which is called exposure.
Exposure: The total amount of light allowed onto your sensor.
Obviously, not everything in your shot will have the same level of luminance: some things in your frame will be lighter and some darker. The difference in luminance is called dynamic range.
Dynamic Range: The difference in luminance between the lightest and darkest areas of your image.
Identifying and (if possible) controlling the dynamic range of your images is essential to producing good work. Photographers must train their eyes to look for contrast in their frames and be able to adjust to achieve a particular feel. Ansel Adams, for instance, is renowned for his high dynamic range pictures, using pure black and pure white to great effect.
Let’s move from the academic to the practical here. I could talk all day about defining these principles, but if you never see them in practice, it probably won’t do you much good.
Let’s take a more in depth look at exposure:
Probably the most common mistake amateur photographers make is not controlling their exposure properly. Under expose your image and it looks dark and noisy, over expose and lose all the detail in your shot. It’s a constant battle for photographers to get the perfect exposure for each shot. Luckily a photographer has three tools in his camera for controlling exposure.
1.) Shutter speed: the opening and closing of a physical (or virtual) shutter to allow a controlled amount of light onto your sensor (film). Shutter speed should be the first thing a photographer goes to when trying to adjust the exposure of a frame. The faster the shutter speed, the darker the image. The slower the shutter speed, the lighter.
Simple, right?
There are some subtleties of shutter speed for the advanced user, but the most important one to keep in mind is motion blur. The slower your shutter speed, the more likely it is to capture movement of an object, or a blur effect. It can look pretty darn cool, but most of the time you’ll want to avoid motion blur, so try to keep your shutter speed above 1/30.
Film/Video Note: If you’re shooting moving images, you don’t have a real choice about your shutter speed, it needs to be a multiple (usually half) of your frame rate. IE Shooting 24FPS with a shutter speed of 1/50.
2.) Aperture: Having written a complete post on aperture, I’ll keep it simple. Your aperture is the opening at the back of your lens that lets light on to your sensor and can be changed by making the opening wider or smaller (changing your f-number). Opening your aperture wide with a close-up subject can give you a cool looking shallow depth-of-field, but can make your images harder to focus. Use a low F-number to focus your image on a single subject. Use a high F-number to keep everything in the frame in focus. More on this later.
3. ) ISO: ISO refers to the sensitivity of your film stock – but wait. You’re probably not shooting on film. Digital ISO still refers to sensitivity, but it refers to the sensitivity (and usually size) of your chip. ISO best practice is really, really easy.
Keep your ISO as low as you can.
In digital photography, cranking up your ISO means adding “gain” to your image and gain = noise, and noise is a very very bad thing (most of the time). If you have a choice, keep your ISO as low as possible.
But what about my flash?
Turn it off. Break it off your camera if you have to (actually don’t). Flash photography is a separate art unto itself, and most consumer and even pro-sumer stock flashes simply… well… they suck. Turn them of if at all possible and use the previously mentioned three methods for controlling your exposure.
What about lighting?
More on this in another post. Again, it’s an art unto itself. Most amateurs don’t have the capacity or tools to do elaborate lighting setups, so do what Stu Maschwitz suggests and use God as your gaffer. Shoot outside or near a window using available light.
Whew, exposure was a big one. What about the others?
Dynamic range is mainly controlled by changing your light, and since you can’t dim the sun or add clouds to the sky, you’re at the mercy of whatever light you have that day. Just keep this in mind.
Direct sun means harsh shadows which = High contrast images (high dynamic range).
Cloudy light usually means diffused light which = low contrast images (low dynamic range).
We can’t add clouds to the sky on a whim to diffuse the sun. But as photographers we have one guaranteed option for softer/more diffused sunlight. That is:
Magic hour (or Golden Hour): The hour before sunrise and sunset. As the sun hits the edge of the horizon, sunlight becomes diffused and soft. It also becomes warmer, changing to a gorgeous gold color.
Be aware that unless you live in Lapland, Magic Hour only last for an hour (or less). Trying to cram all your shooting into those precious minutes can be extremely frustrating. I’ve learned that from experience.
Well there you have it. The single most important post I could ever write on photography. A good understanding of luminance, exposure and dynamic range can launch your photography skills to a new level.
That said, there are a few other important subjects to cover in the basics of photography.
But no amount of reading on photography can replace getting just out there and doing it. Take pictures experimenting with exposure and dynamic range. Try to get a shot in at magic hour and evaluate your work; come up with ways to improve.
Photography, at its most basic, is just a reproduction of light and shadow, so understanding and manipulating exposure and dynamic range are key to producing great images.
[Part one of the Photography Fundamentals series, be sure to check out all 10 posts!]
Rob Elder says
I’m loving this series and the blog. This was probably one of the most concise articles I’ve read on the subject. Thanks!
BrianNotess says
Awesome Rob,
Thanks!
Eric J says
“But what about my flash? Turn it off. Break it off your camera if you have to…”
Yeah that is what i am talking about!
BrianNotess says
🙂 I have yet to see a great picture taken with a built-in flash.