What is an SLR Camera

Unlike the latest trend of small and sleek cameras, we still see the professional photographers carrying huge cameras around their neck. Most of the people are surprised and amazed by these, but they have no clue what these are. Let's try to solve this curiosity.

These are SLR cameras. These are the cameras that are used for professional photography. SLR stands for Single Lens Reflex. Now, that wasn't really self explanatory. So let's dig a bit further.

In a normal camera, light passes through camera lens and hit the film. However, viewfinder does not gets the same set of light that is passed to film. Viewfinder gets a separate set of light. See the attached image for normal camera (I have made this image as simple as possible for purpose of understanding):

1. In this, light(marked in Red color) passes through the camera lens (the long protruding rectangle in front).

2. This light then hits the film (marked in blue) placed at the back of camera. This generates the photograph.

3. Viewfinder (highlighted in Yellow) is present at the top of the camera. As you can see, it does not gets the same set of light as is reflected onto film. It gets a separate set of light (marked in green), and this is what you see through viewfinder.

As is obvious from above, the image that you get might be slightly different then what you see in viewfinder. This is acceptable for casual photography. However, it's a problem for professional photography. And that's where SLR cameras come into picture.

An SLR camera is WYSIWYG, that is, What you see is what you get. SLR camera works on TTL (Through-the-Lens) principal. TTL means that the image is viewed, focused and metered directly through the lens. In an SLR camera, film and viewfinder get the same set of light and so the image generated on film is same as what you had seen in view finder. Lets understand the anatomy of SLR camera through a simple diagram:

1. In an SLR camera, light (marked in Purple) passes through the camera lens (the long protruding rectangle in front).

2. This light hits a mirror (marked in Blue). The mirror is tilted in such a way that it reflects the ight to a pentaprism (marked in Green).

3. This Pentaprism is placed in front of viewfinder. It gets the light from the mirror and reflects it onto viewfinder. So, a viewfinder gets the same set of light that comes through camera lens.

4. When you want to take photograph, the mirror flips up and the shutter (marked in light Blue) opens. This lets the light hit the film (marked in Red), and the image is generated.

So, the image generated in the viewfinder is same as the image generated on the film. That's what an SLR camera is.

Apart from this, there is a lot more jargon that we hear about SLR camera. I will try to touch upon them a bit.

Aperture Control: Aperture is the lens opening. SLR camera allows you to control how much you want to open the aperture. The more the aperture is opened, the more light can enter the camera, and lighter is the exposure.

Shutter Speed Control: Shutter speed controls the duration of time for which you want the light to enter camera. The faster the shutter speed, lesser the length of time the light enters the camera.

Interchangeable Lenses: SLR camera allows you to change lenses. You can chose any kind of lens that best suits the scenario you are planning to shoot. Lenses can be both manual as well as autofocus. So, you get complete choice on that part too.

There are a whole lot of more terms associated with an SLR camera, but you would need to refer to a camera dictionary for that, and this small article won't suffice.

SLR cameras offer you a great creative control over the picture you are taking. They have almost zero lag time, and this makes them ideal for action photography. If you have been playing around with a normal point and shoot camera till now, you may start thinking about moving onto an SLR camera. You'll be stunned by the difference. The cameras are also available in different categories, such as Beginner SLR, Intermediate SLR and advanced SLR. I would suggest you start with a beginner one. They offer you a very good stepping stone, without burning much of a hole in your pocket. You may refer to my article "Top Digital SLR Camera Products Below $1000" to find a good Digital SLR.

I hope now you understand what are those freaky huge cameras hanging around the photographer's neck.