Exposure in Digital Photography

Exposure in Digital Photography - Shutter Speed

Exposure in Photography is determined by the Shutter Speed, the aperture of the lens, the sensitivity of the ISO and the lighting of the scene.

In this post I'm going to talk about Shutter Speed.

Shutter speed refers to how fast the shutter on the camera fires in order to capture the picture. The shutter is like a curtain in front of the sensor that opens when the user presses the button which allows light into the sensor. With a faster shutter speed you can freeze the pinwheel as if its not moving, with a slower shutter speed you can get a smooth effect on the pinwheel.

Shutter speed is measured in fractions of a second. For example a shutter speed of 1/10 means a tenth of a second. Most modern camera's are able to take pictures up to 1/4000th of a second.

Shutter speed is set differently on every camera but there is always an auto option for general photography. In order to customize the shutter speed you need to set the camera into manual mode. from there you will be able to use the dial in increase or decrease the speed.

High Dynamic Range

High Dynamic Range other wise known as HDR, is a process that is applied to the image by the camera to compensate for colour loss, it gives an image a higher Dynamic range. Below you can see the effect in practise, The picture on the left shows how a camera usually captures an image and the image on the right shows a picture with HRD enabled. The way HDR works is by combining three or more photos, one with normal exposure, one over exposed image and one under exposed image. Depending on the lighting of the area it can make an image look more blown out. HDR is very useful in low light areas. If the camera is unable to take a normally exposed image it will instead combine the images to create an effect of normal lighting. Before taking a photo with HDR enabled you have to remove any movement from the shot otherwise the image will come out blurry and you will get a ghosting effect. Some advanced forms of HDR are able to to combat the effect of ghosting. To take a good H

Composition in Digital Photography

There are a few rules that have to be considered when it comes to the Composition of a shot. You have to think about the Simplicity of the shot, the Rule of thirds, lines, balance, framing and avoiding mergers. When it come to taking a shot you have to consider what it is in the shot you are focusing on. Taking a shot of a something basic such as a daisy allow the viewer to only focus on the one item. This shows a simplistic composition. Below is an image that shows the rule of thirds. The image is divided into three equal parts both horizontally and vertically. You can see in the image a butterfly along the vertical line. Lines make the viewer look into the picture more. Horizontal lines give a calming look to the image and the diagonal lines on the tracks give a dynamic look to the image. Balance gives an impression of equality to the image Framing gives a look through something to focus on the item. It's important to avoid mergers in photography

How sensors work in Digital Photography

When you press the shutter release button the shutter is lifted and light is allowed into the camera and hits the sensor. This is the way it worked in traditional camera's aswell but instead of a sensor the light would be projected onto film. There are two types of sensors CCD (Charged coupled device) and CMOS (Complementary metal oxide semiconductor). Both sensors measure light and convert the analog signal into a digital signal which is then saved to the camera's SD card. Advantages of CCD over CMOS: CCD sensors create high-quality, low noise images. CCD sensors give greater sensitivity and fidelity. CCD have 100 times more power over CMOS sensors. CCD require a specialized assembly line to be made. Advantages of CMOS over CCD: CMOS sensors are more susceptible to noise. CMOS have a lower light sensitivity compared to CCD. CMOS consume a lower amount of power compared to CCD. CMOS sensors are easy to manufacture and are therefore cheaper to be made

Digital Photography

Search This Blog