So I set up the tripod, set the bracketing at +/- 2 stops, and press the shutter. 

Here is my first HDR image. I’m not satisfied by the result yet. But I will spare more time to learn more about HDR photography

Now, the light is in front of you, no matter it’s just a natural light or artificial. And you will use the thing in your hand (your camera) to control the exposure. To get the exposure you want, you have some variables to control i.e. ISO, Aperture, and Shutter Speed. Now let’s take a glance at each…

I S O
This term used to describe your camera sensor or film sensitivity. ISO usually presented in number like ISO 50, ISO 100,  ISO200,  ISO 400,  ISO 800, ISO 1600,  ISO 3200, and more jut double the previous number. For each step forward or backward usually to be said 1 stop change.

The bigger the number means that the more sensitive your camera sensor or film is. But these number will also impact to your picture cleanliness from noise/grain. The lower the number, the less noise that visible in your picture.

Aperture
Aperture is a part in a lens construction. You can easily see the aperture of  a prime lens since the design is a lot more simple than zoom lenses. Aperture consist of some blades that create a circle in the center of a lens. That circle will control the amount of light entering the camera.

In terms of photography, aperture represented by f-number or sometimes called f-stop, for example f1.4, f2.8, f4, f5.6, f8, f11, f16, f22, … The bigger the f-number, the smaller the circle created by the aperture.

Aperture also have another effect, the depth-of-field. Depth-of-field is the part of the image that look reasonably sharp. This advantage usually used in portraiture to isolate the subject from the background. The bigger the aperture (small f-number), the depth become more shallow.

Shutter Speed
Shutter is the device that cover the camera sensor. When you push the shutter button on the camera, the shutter will open so the sensor or film will get exposed by the light that enter the camera through the lens. The duration of time when the light hit the sensor refers to shutter speed. The faster the shutter speed, the less amount of light will enter the camera.

Application
The control for exposure means that you controlling those factors above, making combination of those factors so you’ll get the exposure to your creativity. Change in one factor will change the exposure to the sensor and subsequently change the look of the final image.

For example, you set your ISO to 100 to lower the noise/grain in your final image. To get normal exposure of the subject at aperture of f1.4, the shutter speed shows a value of 1/500. If you want to get more depth, you need to closing down the aperture, let’s say f4. Stopping down to f4 will have the consequence to slow down the shutter speed to less than 1/500 to get the same exposure.

Metering

Metering is about how you “meter” your exposure.
Every modern cameras already have a built-in exposure meter. The metering system provided  usually consist of three type of metering, spot, center-weighted, and matrix metering.

Here’s the basic of metering. First of all, you have to be aware that the camera meter will consider the subject to have the luminance of middle gray (12% or 18% gray). So, if you point your camera to dark subject, the camera meter will set the exposure to brighten the subject so it has the luminance of middle gray. For example, if you point the camerea to a pure black subject, the camera meter will consider that the subject as middle gray which need more light. So the meter will set to slower shutter speed to capture more light, if you already set the ISO and aperture. So the final image will shows a gray image, not pure black.

The most sophisticated metering method is the matrix metering. This method will account for every part in the frame as we compose so the whole image have good exposure. But still, nothing is perfect. Even a matrix meter can be fooled by certain condition. In this case, you can set the exposure compensation value so your image will have the exposure as you want.

Well, that’s my idea of exposure and metering, I hope this can be a gateway to amateur like me, to understand more about exposure and metering.

Please correct me if I’m wrong…