Saturday, May 2, 2015

Photography Basics

"Getting the technological foundation to make perfectly exposed photographs was easy, but amounted to nothing on its own. I simply had to commit myself, to express feelings about what I was undertaking." --Bjorn Rorslett
Capturing photographs is easy. Anyone can do it. Most cameras can do it completely on their own nowadays. But if you are not controlling the image and just letting the camera decide, you are a capturing pictures and not making photographs.
"The difference between an amateur and a professional photographer is that the amateur thinks the camera does the work." --David Hemmings
Cameras can do all of the work for you, but that amounts to nothing. In order to make meaningful images, you must take the camera out of auto-mode and force the camera to capture the images as you want them to be captured.
"You don't take a photograph, you make it" --Ansel Adams
In order to force the camera into capturing the photograph the way you want it to be, you must know what everything does. It occurred to me that not everyone reading The Urban Exploration Photography Blog has this basic foundation. So let's talk about some of the controls that are on your camera.

Broken Angels - Bodfish, California
A large aperture was used for this photograph.
Aperture is an adjustable opening in the lens that lets light into the camera. Adjustments are measured in "f-stops" and the exact f-stops available will vary from lens-to-lens. The smaller the f-stop number, the larger the opening (aperture) will be in the lens and the more light will reach the camera. The larger the f-stop number, the smaller the opening (aperture) will be and the less light will reach the camera.

The larger the aperture, the smaller the depth-of-field (amount of the image in-focus) will be. The smaller the aperture, the larger the depth-of-field will be. A small aperture like f-16 will have a large depth-of-field, while a large aperture like f-2 will have a narrow depth-of-field.

However, because of something called diffraction, generally speaking, the larger the aperture the sharper the image. This demonstrates that depth-of-field and sharpness are two different things. You can have tons of depth-of-field but a fuzzy picture and you can have very little depth-of-field but have a sharp image. So choose the aperture that gives you the depth-of-field and sharpness that you desire.

Purple Beretta - Tehachapi, California
A fast shutter speed was used for this image.
The shutter is a curtain in the camera body that opens and closes to allow light onto the sensor or film. Shutter speeds can be super fast or super slow or anywhere in between.

By controlling the speed of the shutter you control how movement is captured. A quick shutter speed will freeze motion while a slow shutter speed will show motion as a blur. You must choose a shutter speed that is appropriate for how you want motion captured. A slow shutter speed will likely require the use of a tripod to prevent camera shake.

Copy Machine - Mojave, California
A "grainy" high-ISO image.
ISO (sometimes called ASA or "film speed") is the sensitivity of the film or sensor. The lower the ISO number the less sensitive it is to light, while the higher the ISO number the more sensitive it is to light.

In order to achieve that greater light sensitivity, the higher ISOs will create a more "grainy" or "noisy" image. Lower ISO images look "cleaner" than higher ISO images. Maybe you want the cleanest image possible, or maybe you want a grainy-looking image. Choose an ISO that is most appropriate to how you want the image to look.

On A Brighter Day - Tehachapi, California
A challenging exposure situation.
Aperture, shutter speed and ISO work together to create an exposure. An adjustment to one will have an effect on the others. For example, if you increase the aperture, you are now allowing more light to enter the camera and perhaps you will have to use a faster shutter or a higher ISO setting.

Cameras nowadays all have pretty good light meters built-in, and will 99% of the time get the exposure correct. Under extreme or unusual lighting conditions you may find that the camera's light meter is incorrect and you may have to figure out the correct exposure yourself. You can change the exposure in manual mode by changing the aperture, shutter speed and/or ISO.

Something else that should be mentioned is dynamic range, which is the sensor's or film's ability to handle highlights and shadows. In a scene with bright highlights and dark shadows, you simply cannot capture the full scene because the sensor or film is not capable. There is not enough dynamic range to keep details in the highlights or the shadows (or sometimes both). This is a limitation that you should be aware of, and you should consider how this may effect the image. You may want to over-expose slightly to retain shadow details or you may want to under-expose slightly to retain highlight details.

Rusted Bolt - Loraine, California
Focus is what visually separates the bolt from the busy background.
Auto-focus works well on most cameras. I don't mind manually focusing to make sure that I have it where I want it. The smaller the depth-of-field the more accurate you must be with focusing.

Sometimes you may want something in the foreground to be in focus and the background out of focus. Sometimes it might be the other way around. You want to draw the viewer right to the subject and careful use of focus is one way to accomplish that.

Do Not Disturb - Mojave, California
This image is toned a little warmer than what the light naturally was.
Different lights give different hues. Some lights are warm (orange) and some are cold (blue). Auto-white-balance typically does a good job of correctly choosing the correct setting for the scene to give a natural-looking hue.

Don't be afraid to play around with the white-balance. Maybe you want the image warmer or cooler for some reason. There is no right or wrong white-balance setting, just whatever looks right to you.

"Your first 10,000 photographs are your worst." --Henri Cartier-Bresson
The best way to learn the basics of photography is to get your camera out and use it. Play around with it. Try different things with it and see what happens. There is nothing like hands-on experience.
"The single most important component of a camera is the twelve inches behind it." --Ansel Adams
Once you've got a good grasp of how a camera works, then you can start on the hard part of photography: creating art. To create meaningful images you must have photographic vision. You must dig into your mind and heart.

No comments:

Post a Comment