There are four basic building blocks that make a photo: light, the image sensor in your camera, the setting of that camera, and you, the photographer. All four of these are key to a photo. By breaking each of these down we can see how a photo takes shape.
Photography is literally translated painting with light. Think of what a camera does, scientifically. A camera simply records the light bouncing off the objects within its field of view. Every beam, every color abortion, every distortion, is captured at the moment the shutter snaps. And so, without light, there is no photo.
Even though there is no photo without light, likewise, without something to capture it, there is no photo as well. The image sensor is the plane on which the light creates its image. A digital image sensor is comprised of thousands small light sensors. Each of these sensors corresponds with a pixel. A pixel is a digital measurement of one point of light. Because of that corresponding relationship, camera’s sensors are measured in pixels, this measurement is called: resolution. For instance, the Canon 5D Mk II has a resolution of 21.1 megapixels (MP) — or 1000 pixels multiplied by 1000 pixels, equalling 1,000,000 pixels. This measurement is achieved by taking the horizontal pixel count: 5616, and multiplying it by the vertical pixel count: 3744, making a grand total of 21,026,304 pixels. Rounding that up for marketing purposes, you get 21.1 MP. Each sensor is comprised of three filter layers, a blue filter, a green filter and a red filter. When the light hits these sensors it records the luminance value of each of these three color wavelengths and coverts that to a numerical value. That numerical value can then be reproduced to recreate the original image.
Digital image sensors are often compared to the standard of film. In measurements ranging from light sensitivity to color accuracy to physical size. The standard of 35mm film is what digital single-lens reflex are most often compared to, and ultimately what they aim to replace. Perhaps the single most differing factor is sensor size. Since in a 35mm camera the image sensor is the film, the typical frame size is 24mm tall, by 36mm wide. This size is referred to as “full frame”. Up until recently, full frame DLSRs have been quite expensive, and even though they are becoming more reasonable, they are still fairly rare within the pro-sumer level of cameras. DLSRs can have frame sizes ranging from as large 28.7mm by 19mm to as small as 17.3mm by 13mm.
Noise is a problem unique to digital recording, but can be compared to the concept of grain, which is unique to film. Noise is a random variation of brightness or color information. It’s an unfortunate side effect of using digital equipment, but like a stereo with a buzz, is usually drowned out by color information with strong values. Because of that, noise is much more common in low light pictures, where there isn’t the “volume” of light to cover it up.
There are many file formats associated with digital photography, the three most common are: JPG, RAW and TIFF. JPG, while being the most ubiquitous is a “lossy” format and will degrade the image every time it is manipulated. Because it’s compressed each time it’s saved, the formate creates small files, which is the trade off for losing quality. TIFF is a lossless format, although it can be compressed within the container it typically is not. TIFF’s file sizes are usually quite large, due to the fact it retains most of the original information. RAW is a container file. It can house a myriad of compression types, but it’s used to house the most color information possible from the camera. The reason is that the only compression a RAW image has is the camera’s internal compression. It cannot be manipulated and must be converted to be so.
There are many different types of memory cards. The most common is compact flash, but the benefits of each type are typically less influential in their use than the political war between each camera maker.
Now that we’ve covered the two fundamental building blocks, light and the image sensor, we’ll move on to the less fundamental, but still vital ones. The camera settings will make or break a photo. ISO, shutter speed, aperture and white balance are the core of your camera’s settings. ISO is a measurement of the sensor’s sensitivity. The lower number, e.g. 100, requires more light, but produces a higher quality image. The higher numbers, e.g. 800, 1200, use less light, but you start having problems with noise. Shutter speed is how long the camera’s shutter is open. The longer it’s open, the more light it lets in, this is typically in balance with the aperture. Aperture is the size of the lens opening. The larger the hole, the more light comes in. White balance, also called color temperature, is one of the more interesting settings. Our brains are fantastic creations, they calculate complex equations without us even realizing it. In this case, most people don’t realize that light is never purely white. Light has a “warmth” or redness, or a “coolness” or blueness, depending on it’s temperature. The white balance setting is used to tell your camera what temperature your light source is, so it correctly interpret what “white” is.
A few, less core, settings are: lens focus, lens zoom, digital zoom and stabilization. Quickly, lens focus is a setting to determine at what distance things are in focus. Lens zoom is using glass and optics to make objects magnify upon the image sensor. Digital zoom is a terrible invention, don’t touch it. Stabilization is a computerized algorithm to counteract a shaky hold on your camera. Do not use stabilization if possible. It can sometimes help you get a crisper image, but more often than not, creates a slightly soft image. Either hold your camera so there’s no shake, or use a tripod.
There are typically three types of lenses: wide-angle lenses, normal lenses and telephoto lenses. Wide angle lenses have a focal length of 24-35mm and cover a 84° to 64° viewing angle. Normal, or standard, lenses cover 36-60mm lengths and 62° to 40° viewing angle. Telephoto lenses have viewing angles from 30° to 10° and are quite long.
There are many different types of filters and camera accessories, all of which have a purpose and a use, but more often than not, you’ll use the basic camera settings and no more. A polarizer is a great filter, it filters out all but one angle of approaching light, thus eliminating reflections and refractions. A graduated neutral density filter can come in handy for landscapes where the sky is blowing out and the ground is too crushed. An extension tube can be used to create macro shots with a non-macro lens.
The basics of digital photography remain very similar to those of traditional film photography. Some new limitations have cropped up, but are balanced with benefits, such as the vitally unlimited shot quantity. Being reminded of the basics from time to time is always a good thing.
Journaled Time: 2 hours – reading and taking notes
Total Class Time: 2 hours
