Lens aperture is one of the key tools for photographers for adjusting the exposure and for achieving specific creative depth of field effects. The lens aperture is an adjustable hole created by a diaphragm within the camera lens. When you change the size of this hole, you change the amount of light allowed to pass […]
ISO (sensitivity)
This setting increases the camera sensor’s sensitivity to light, and it's used mainly so that you can still use fast shutter speeds even in low light to avoid camera shake or subject movement. The more you increase the ISO, though, the more the image quality degrades.
ISO (sensitivity) and how it works
ISO is the unit used to measure and adjust the camera sensor’s sensitivity to light. With film, the ISO setting (or film ‘speed’) is part of the film’s physical and chemical properties and can’t be changed. With digital cameras it’s possible to ‘turn up the volume’ on the sensor to make it more sensitivity to […]
Noise and noise reduction
Noise is the digital equivalent of grain in film. It’s random electrical signals captured by the photosites on the camera sensor, and usually this background noise level is so low compared to the brightness of the captured picture itself that you just don’t notice it. But if you start increasing the camera’s ISO setting, the […]
Flash photography basics
Sometimes the ambient light level is too low for successful for photography, or it’s the ‘wrong’ kind of light. This is where photographers turn to flash (or ‘strobe’, if you’re in the US). Flash works by emitting a very short, very powerful burst of light. Energy is stored in a capacitor in the flash head […]
Camera shake and how to avoid it
Camera shake is blur caused by camera movement during the exposure. It happens with indoor shots or outdoor shots in poor lighting or at night, when the low light levels mean the camera uses a longer exposure and hence a slower shutter speed. The slower the shutter speed, the more likely it is the camera […]
Exposure and how it works
Exposure is all about making sure the sensor gets the right amount of light. Without camera exposure controls, pictures taken at night would be pitch black, and those taken in bright daylight might be burned out. There is actually a fairly narrow ‘window’ of light intensities which sensors can record, and real-world lighting conditions vary […]