slrHQ.com

"Camera Basics"

This lesson is for people who know nothing really about camera tech and want to get a basic understanding.

The following lesson will cover the very basics, Shutter, Aperture, Lenses, and Frame Rate and detail how you can control these to produce better photography or video.

I) Shutter:

The shutter controls the length of time the sensor or film is exposed. In other terms it controls how long the exposure will be.

A very fast shutter will make fast moving object in motion appear very sharp. It will have a higher number on the bottom of the fraction 1/800, 1/1000 etc. This fraction is a measurement in time: 1/800th of a second.

A slow shutter will make objects in motion appear soft or blurry. They will have a number like 1/30, 1/48.

How can you use this in Video?

In video and film the shutter can be used to give the film a particular vibe. For example, in Saving Private Ryan, a very fast shutter speed was used during the combat scenes. This gave it a very fast crisp look with no motion blur and a vibe that felt very real and intense. The same was also done in Gladiator.

Now a slower shutter will do the opposite. It will give the image a lot of motion blur. Normally for a film that doesn't involve a lot of action it's very common to shoot at around a 1/48 shutter or 1/60 depending on the frame rate your camera shoots. 1/48 for a camera that shoots 24frames per second (fps) and 1/60 for a camera that shoots 30fps. However sometime's a 1/48 can make everything feel soft if your on a longer lens and shooting hand held because it will cause a lot of motion blur, so it's ok to turn it a little faster depending on your situation. But for starters try a 1/48.

In photography be sure to use a tripod if you shoot lower then a 1/60 shutter or you will get blurry images unless you are extremely steady.

II) Aperture, (f stop, iris)

The aperture often referred to as the "Iris," or F-stop, is the opening in the lens. Think of the iris in your eye when you shine a flashlight into and how it closes down to make it not so bright. Well the aperture in a camera lens does the same thing. It can open up or close down to adjust how much light is allowed in.

Now this is responsible for 2 very important things.
1, it can be used to control the exposure similar to the shutter the more open the iris the more light gets in.
2, it controls the depth of field.

Depth of field: is how much room you will have with your focus. For example, a very shallow depth of field will give you only a few inches of Focus, and a very deep depth of field will make almost everything in focus. So if you are filming someone talking and want everything behind them out of focus but their face in focus you will shoot with a shallow depth of field. Numbers like 2.4, 2.8, 3.2 or 4. Often called an F stop. f2.8, f3.2, f4 etc. To make everything in focus shoot at a more closed down Iris like a f11, f16, f22

A shallow depth of field is a very big part of achieving the "film look."

There are a few other ways to control your depth of field besides the aperture. One is the size of the camera's sensor. The bigger the sensor the shallower the depth of field. So a camera like the Canon 5d has a full frame sensor so will give you more depth of field. We will cover the physics of all this in later lessons.

III) Lenses

Another contributor to a shallow depth of field is the length of your lens. So zooming all the way in with your camera will also give you a shallower depth of field. So a lens that's longer, like an 85mm, 105 or 200mm will give you shallow depth of field, where as a wider angle lens, 10mm, 14mm or 24mm will give you a deeper depth of field.

The camera's lens can also control the compression of an image. Meaning a longer lens will make things feel very compressed. So if someone is standing 10 feet from a wall and you shot them on a long lens, the wall will seem closer to them that it really is. This is because the distance is compressed into a spatially flatter image. A wider lens spaces everything out. Think of a skateboard video shot on a fisheye lens, you can see a lot more of the scene, and objects feel very far apart from each other.

To get a nice film look use a longer lens on your close ups. Something like 70mm or 85mm. This will give you a nice shallow depth of field with the background slightly out of focus. Mix that with an f stop like an f2.4 or f4 depending on the size of your sensor and you'll have a beautiful close-up.

IV) Frame Rate

The final factor in the "film look" comes from the frame rate.

Most films shoot at 24 frames per second. This means the camera exposes 24 frames or snaps 24 pictures every second. This gives the picture what some people say a dream like look. I however think it's overrated.

V) ISO

ISO is basically your film or sensors sensitivity to light. So the higher the ISO number the more sensitive it is to light giving you a brighter exposure. The draw back is the higher the ISO the more grainy your image will be. When possible try to shoot a lower ISO to eliminate grain. Especially with digital cameras. With a film camera shooting with a fast ISO can give you a different type of gain which makes for an interesting style. Film grain looks a lot better then digital grain which on some camera's like the "RED" it will cause weird looking blue grain like scratches that can ruin the image.

Please visit http://www.slrhq.com/forum for further discussion.