• what is iso

What is ISO – Understand ISO and get out of the Auto mode


ISO is one of the most important camera settings, you will significantly improve not just the quality of your photos, but also the variety of them too by making good use of the ISO setting. Years ago, in the days of film, now being lost in the midst of time, the film manufacturers used to print a number on the side of the box. This number represented the speed of the film, that is, how sensitive the film was to light, and the higher the number, the more sensitive was the film to light. Using a higher ASA film made it much easier to take photos in low light or to take fast moving subjects, i.e sports or birds in flight. The problem was, especially in the early days of film, the higher the ISO, the more 'grain' was introduced to the negative and consequently the prints. In this digital age, the term ASA has been replaced with ISO, and 'grain' is now referred to as 'noise'. With film, yo were locked into the ASA for the whole roll of film, the only way of varying the ASA while shooting was to carry another camera body loaded with a different film. How times have changed, we are now able to vary the ISO on a frame by frame basis, plus in my opinion the quality of high ISO images is now better than it was with film. [do action="tl-linktocurriculum1"] [/do] Here's a simple analogy showing how the sensitivity of the camera sensor changes when you adjust the ISO. If you arrive at a cinema show a bit late, everything looks really dark when you go in doesn't [...]

What is ISO – Understand ISO and get out of the Auto mode2017-05-29T16:22:15+01:00

The Exposure Triangle – Aperture, Shutter Speed and ISO


There's more info on this topic at www.pixpa.com. The exposure triangle explains how the individual aspects of exposure, i.e aperture, shutter speed and ISO, affect the final exposure of the photo. It's a useful way of describing the relationship between the three aspects of exposure. Each side of the triangle represents one of the three variables, aperture, shutter speed and ISO. Adjusting just one of these will will change the appearance of the photo based on your settings. It's important to understand that unless you are in the Manual Exposure Mode, changing any of the three settings will not make the image darker or lighter. That's because in any of the semi auto modes (such as A/AV, S/TV, or P), the camera will automatically compensate by changing one of the other settings. Aperture The aperture, which is part of the lens not the camera, controls the quantity of light entering your camera. Just like the pupil of the eye, the larger the aperture, the more light is let in. The aperture is set using what is known as F numbers, i.e f2.8, f4, f5.6, f8 and so on, and the smaller the number, the larger the aperture (only a small elite of quantum physicists know why this numbering system is so perverse!!). These numbers are sometimes referred to as a 'stop', and each stop allows in twice as much light as the previous one, so or example f4 lets in twice as much light as f5.6 Shutter speed The shutter speed, measured in fractions of a second, controls the duration of the exposure. Just like window shutters, the longer the shutter is held open, the more light is let [...]

The Exposure Triangle – Aperture, Shutter Speed and ISO2020-06-11T18:48:49+01:00
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