Photography Part 2: Exposure
It’s been about 2 weeks since my first post, photography basics, which reviewed the equipment you need in order to start taking better photos. So, I think enough time has passed for everyone to save up a few thousand bucks, and make their purchases, right? Either way, onto the next logical topic: Creating a proper exposure.
Your exposure is essentially how light, dark, or just right your photo is. You obtain this by combining the proper aperture, shutter speed and ISO setting. (external light source or flash will also play a role in proper exposure, but I’ll cover that another time).
Each one of these variables (aperture, shutter and ISO) play a factor in your exposure. They each represent something unique, but need to work together in order to get a desirable result.
The quickest and easiest way to calculate the proper combination of these factors is by utilizing your cameras built-in light meter. In most cases, you’ll see the light meter towards the bottom of your display while looking through the viewfinder. Your cameras light sensor will judge the required settings by what is currently in focus. In other words, if you aim your camera at the bright sky, your light meter may tell you that your settings are over exposed and that they need to be altered. Similarly, if you aim your camera in a shaded area your light meter may tell you that your settings are under exposed and that you’ll need to, again, alter your settings. You can alter these settings by changing any one or all of the three factors mentioned above. Once the indicator on your light-meter is directly in the middle, you should have a proper exposure. However, there are many ways to obtain this exposure, and the one you choose might not be accomplishing the “look” that you were initially going forâ€¦ When I first started taking pictures I would only adjust the shutter speed in order to create a proper exposure. Unfortunately though, that technique was short lived until I found out that the slower my shutter was, the blurrier my photos became. Therefore, I needed to find a good balance between all of the factors involved in order to create a desirable photo for every specific instance.
When you understand the role that each factor plays within your exposure, you’ll have much more control over the results of your images. I’m going to walk through some of these factors to help give a better idea of what to expect when altering your aperture, shutter speed and ISO.
Click the link below to read the rest of the post!
Aperture: Your aperture is commonly referred to as the “F-Stop”, and is defined by the amount of light that you’re letting through your lens, to your light sensor. The lower the aperture (f/1.4, f/2, etcâ€¦), the bigger the opening in which you are allowing light to travel through. However, the aperture serves a dual purpose. It will also dictate how much or little an image is in focus. If you have a very low aperture, the background of your image will be very blurry (see the image below of Jen below).
On the contrary, if you have a high aperture (f/11 – f/22), the background of your image will be very sharp and in focus (see the image below of Jen in the field). (Note: a high aperture will also help you achieve a killer lens flare like the one in this example)
In terms of fashion photography, the focus is primarily the clothing rather than the background, so it makes sense to have a low aperture to blur out any distracting background imagery. On the flip side, however, sometimes your surroundings may compliment your outfit, so it makes sent to have it more in focus. Regardless, your aperture is going to have a direct effect on your exposure. The more light that you’re allowing through the lens, the faster your shutter must be in order to compensate (and vice versa). In other words, if you’re shooting at an f/2 because you want a really blurry background your going to need a slightly faster shutter speed. Otherwise, you’re going to end up with an over exposed image.
Shutter speed: Shutter speed refers to how fast the actual shutter opens and closes. The longer you leave your shutter open, the more light you’ll allow through. An example of a typically slower shutter speed would be 1/15 s, while a faster shutter speed would be 1/250 s. While keeping your shutter open longer allows more light to hit the sensor, it also creates more risk of motion blur. If you’re the type of model who likes to dance around moving quickly from pose to pose, your going to need a slightly faster shutter speed. The faster you move, the faster you’ll need your shutter to be (see the image below of Jen jumping. There’s no motion blur because my shutter was at 1/3200 s)
Typically speaking a shutter of at least 1/40’s should stop general motion. However, (for the sake of an extreme example) if you’re photographing a sporting event you’ll probably need to shoot closer to 1/250 s. The faster the motion, the faster your shutter should be. (Example: turtle racing: 1/40 should suffice â€“ Car racing: 1/1000 should suffice). Keep in mind, the motion you’re compensating for is not just within the subject itself but also within the steadiness of the photographers hands.
ISO: Your ISO setting is determined by how light sensitive your film (sensor â€“ in the digital sense) is. The higher your ISO, the more light sensitive your sensor will be. In other words, if you set your ISO to 400 it will receive more light than if you set your ISO to 100. As a reference, think back to when disposable cameras were a hot commodity. The camera would say ISO 400 â€“ good for indoor shots. OR, ISO 100 â€“ good for out door shots. However, you should think of your ISO setting as a last resort. Far too often photographers crank up their ISO as a crutch in low light situations. As a rule of thumb, I always try to keep my ISO at 100 and rely on external light sources to ensure my images are properly exposed. I know that we’re not quite there yet though, so if you find your self in a dimly lit room and you need to adjust your ISO, I won’t be upsetâ€¦ for now anyway. The problem with adjusting your ISO to compensate for a dark setting, is that you’re camera will degrade your image. You’ll start to notice a much grainier image when your ISO is set high. This grain is known as digital “noise”. Most new DSLR’s have great noise reduction capabilities, but the fact of the matter is, the lower your ISO, the better your overall results will be.
So you can see how each factor will not only determine your exposure, but also the appearance of your photograph. If you find yourself consistently shooting indoors or in dark areas, you’ll quickly notice that you have very little control over the artistic aspects of these settings and that you’ll be resorting to very undesirable settings simply to get a decent exposure. This is where an external light source (flash) comes in handy. It add’s another (seemingly confusing) element to the equation, but it certainly is the remedy for good indoor (or dark setting) photographs. Due to it’s complex nature, I’ll save it for another post and dedicate the entire article to it.
I hope you’ve found this explanation of exposure to be insightful, and not too confusing. Worst comes to worst, just remember that you have the benefit of a digital camera which will allow you to see instant results. So play around with your settings and see how one setting verse another will drastically change the look and exposure of your photograph.
If you find this series to be helpful, consider following me on twitter where I sometimes say other helpful things. You can also check out my portfolio/blog at encourageothers.com to see some of my personal work and confirm that I’m not just making this stuff up as I go along.