subject: Photo 101 - How To Use The F Stop [print this page] Shooting with a camera and adjusting the settings manually can be an intimidating task to the new photographer. Veterans of the craft will no doubt remember pictures that they ruined by reading the light wrong, or the irreplaceable moments in time lost behind a lens cap. As photographers our job is to be the conductor to a symphony of moving components, gently influencing each element to ensure that the end result is more than just the sum of the parts.
Without understanding the elements of photography individually, it is impossible to understand how they relate to the whole. So, lets start looking at the inner workings of our images with one of the most unfamiliar subjects: Aperture.
Defining Aperture
Aperture is simply what controls how much light is exposed to your film (or your digital camera's sensor). It can be opened and closed using your camera's F-Stop on your camera which is usually found on the ring around your lens between the body of the camera and the focus ring. If you've ever looked into someone's eye as light was shone into it, you have a pretty good idea of what the aperture does - it works just like a pupil.
Most cameras have an F-Stop range of 1.7/2.0 to 22 or so; the range of values usually increase with the cost and quality of the camera. By looking at the numbers around your lens, you can see your camera's range. Lower F-Stops expose the film to more light and are more open while high F-Stops shut the light out by closing down the aperture.
How Aperture Impacts Images
Using your F-Stop to purposefully manipulate the aperture of your camera will allow you to change the depth of field shown in your photographs. If you don't know what "depth of field" is, it describes how much of your image is blurry and how much is sharp. Aperture directly affects the amount of time a frame is exposed; the longer the film (or sensor) has to absorb information, the greater the depth and clarity of the image.
For instance, if you were to take a photograph of a line of dominoes from one end using a low F-Stop number (an open aperture), you would probably see one or two dominoes clearly and the background ones as blurry. Open apertures create a shallow depth of field. If you were to then take the same photograph with a high F-Stop (a closed aperture), you would see many more dominoes clearly down the line and get a much greater sense of how far away they might be.
Fun Aperture Experiments
Playing with the aperture on your camera can be great fun once you have a bearing on what it does. Here's a couple of ideas to try the next time you're out shooting and you want to test it out:
1) Take every photograph twice - once at a high F-Stop, and once at a low F-Stop.
2) Challenge yourself to shoot an entire roll at one F-Stop, then switch it up.
3) Put your camera on full manual and adjust the F-Stop on the fly to adjust for light
Don't forget to adjust the shutter speed of your camera to allow for more or less light (faster speeds for more light, slower speeds for less), or you may end up with overexposed or underexposed images. Many digital cameras have a fantastic option called "Aperture Priority Mode" which allows you to choose an F-Stop value and will then adjust your shutter speed automatically. It is worth pointing out that the best conditions for experimenting with aperture are overcast or cloudy days. When faced with bright or low light, your options for F-Stop values will become limited.
Of course, the best way to improve your photographic skills is to continually take pictures. Get out there and find those photographs!
