Digital Photography 101 - Part 1

Photography 101 – Part I

The Camera

1. Prelog - The world of photography contains many terms that we may not be familiar with, out of our everyday living, and we need to learn how to use them in order to fulfill the potential of photography. In this article, I will explain many of these terms and will describe (briefly) how they relate to the photos we shoot. I hope you'll enjoy and learn.

2. The Camera

a. Body – the camera's body is one of the few parts that's really hard to get along without. It holds all the essential parts and protects them from harm's way and other stuff like hits, moisture, drops etc. We can find plastic bodies and metal bodies, the plastic ones are lighter and usually cheaper, while the metal bodies are more durable, professional and expensive. The metallic alloys that make the skeleton of the body are usually magnesium, aluminum and other light metals – the choice of which determines the price tag.

b. Shutter – while shut, the shutter prevents the light from reaching the camera’s sensor, and dictates the length of time during which it reaches the sensor, while it's open. There are horizontal, vertical and aperture-combined shutters, the latter usually found in cheap compact cameras. The shutter is produced of light and durable materials and is meant to last for tens of thousands of cycles. When it's worn out it needs to be replaced. The shutter speed varies from 1/8,000 of a second in the more professional cameras, to 1/4,000 in the entry-level DSLRs, and 1/2,000 in the compact cameras, and for as long as 15 seconds, 30 seconds and even 'bulb' mode, in which the shutter is left open until told otherwise and can hold exposures of few minutes. Fast shutter speeds will "freeze" the motion in the frame, and slow shutter speeds will smear the motion. The guideline for avoiding blurry photos due to shaking hands is to use shutter speed higher than 1/(focal length); for example: if the focal length is 200mm, use shutter speeds of at least 1/200 to avoid smears.

c. Mirror – it's not to show how pretty you are, but to reflect the light which enters the lens upwards, where it enters a prism or a mirror system and exits into the viewfinder. The method in which the mirror system works strongly affects the brightness and other factors of the resulting image. The mirror system reflects the light through a semi-transparent mirror into two other sensors – the focus sensor (see focus) and the light metering sensor (see light-metering). When the shutter release button is pressed and the photography process takes action, the mirror lifts up, the shutter fully exposes the sensor, exposure occurs, and then the shutter closes and the mirror drops down. This process, in which the mirror is up and there is no light going through the viewfinder, is called Viewfinder Blackout, and it is critical in DSLR since the longer it is, the harder it gets to track objects in motion.

d. The Viewfinder – we already mentioned that light enters the lens and, by going through a set of mirrors, it eventually reaches the viewfinder. The main parameters regarding the viewfinder are its size, the magnification and the frame coverage. The size of the viewfinder says a lot about how comfortable it is, and of course - the larger it is – the easier it gets to take a look. The magnification factor implements the size of the projected image in the viewfinder, and the frame coverage suggests about how much of the frame is visible in the viewfinder (usually between 91%-100%). While looking through the viewfinder, we can find important information about the exposure, the scene, focus and pretty much everything we need to know (well, almost). Bear in mind that the distance from the viewfinder to the lens is exactly the same distance as the lens from the sensor, due to the fact that both need to be in exact focus. Compact cameras (not DSLR) use two main types of viewfinders: the optical VF (viewfinder) and the electronic VF or EVF. The optical VF uses a separate window and lens system to simulate the image received at the sensor, and it's main drawback is that there is some difference between the image in the viewfinder and that on the sensor because of the two different angles observing the scene. The Electronic ViewFinder (EVF) is, in fact, a mini-LCD screen inside the viewfinder; its disadvantages are that usually suffers from low resolution and that it lags behind the actual scene. Given these drawbacks, why use them on compact cameras? Good question; mainly because it saves the battery and some screens don't work as well in broad daylight. Tip: some viewfinders have diopter adjustments for those of us who wear glasses.

e. Bionet – that's the ring on the body of DSLR cameras into which we attach the lens. It is almost always made of metal and its job is to keep the lens tight on the body and to transmit, via electric contacts, information from the camera to the lens and backwards - regarding focus, aperture etc and provides electricity. The bionet also shifts torque from the camera to the lenses without an internal motor.

f. Flash – its job is to illuminate the subject under low light conditions or as fill flash to weaken shadows. It's recommended that you use external flash, which fits on the "hot-shoe" on top of the camera. The hot shoe holds the flash and transmits information from the camera to the flash regarding exposure. for further info read the Flash Photography article

g. Assist light – under dim light conditions and total darkness, the focus system needs some help illuminating the subject for focus. Some assist lights use an ordinary white light, some use a pattern and some project a grid on the subject. All flash units assist the focus using a red grid. Some cameras also use the assist light to reduce the "red-eye" effect.

h. Batteries – what can you do, digital cameras need electricity and they are demanding. The DSLR cameras and the more advanced compact cameras use Lithium-Ion batteries and the cheaper compact cameras use AA rechargeable batteries. Today Ni-MH batteries are the best AA on the market and hold more than 2,700 mAh of juice, more than ever before. And the chargers have reduced the charging times from several hours in the past to even less than an hour for a full charge (!) Battery life is affected by the amount of photos taken, usage of the LCD screen, usage of flash, etc. By using the camera correctly you can squeeze more shots from each pack.

i. LCD – that tiny screen at the back of your camera is one of the greatest revolutions of digital photography. LCD stands for Liquid Crystal Display, and today they provide excellent viewing quality with rich colors and low power consumption. The screen is used both for building a composition and reviewing the image after the shot was taken. Turning the screen off will save batteries when needed.

j. Light Meter – all cameras today contain a light meter, unlike in very old cameras. The light meter is a sensor that meters the amount of light which enters through the lens and onto the sensor, using various method: Matrix - covering the entire frame; Center weighted – which gives 90% importance to the center of the frame and 10% to the rest ; Spot Metering – which meters only from the tiny spot in the center of the frame. There are several kinds of sensors: from simple grey levels to the 1,005 pixels RGB sensor found in Nikon cameras.

I Hope you enjoyed part I of Photography 101.

Join me in the next episode – The Digital System

Yours truly,

Roie Galitz

For more photography articles – composition, Depth of field, Filters, Flash Photography, infrared photography, Sunset photography, Blue Channel, Panning