BetterPhoto Q&A
Category: Problems with Images

BetterPhoto Member		photography basics What do these terms mean??? ISO,F-number,Focal length, aperture Exposure time,etc. To love this question, log in above April 30, 2011

- Carlton Ward Contact Carlton Ward Carlton Ward's Gallery		Hello Varun, ISO is a simulation of film speed so ISO 100 is less grainy (known as "noise" in the digital realm) than ISO 800 but sometimes you have to use a higher ISO setting to get the shutter speed (exposure time) or DOF (Depth of Field aka F-Stop) to capture the image the way you want to. Focal length is the lens measurement and there are fixed lengths (also called Prime lenses) such as a 24mm 50mm or 85mm and telephoto lenses like a 24-70mm or a 70-200mm which are adjustable with a zoom ring so you can zoom in and frame your shot while looking through the viewfinder. Proper Exposure is the basis of all that IS Photography and you would really do yourself a huge favor if you signed up for Jim Zuckermans "Perfect Digital Exposure" class or one of the many other Exposure classes Better Photo offers. It will give you a solid foundation and take the mystery out of what these terms mean and teach you how to make it work more artistically so you can capture an image the way you want to capture it. Learning Photography is a wonderful journey and as you learn, practice & experiment - your skills will develop and you will see improvements as you go. Enjoy the ride :) Carlton To love this comment, log in above April 30, 2011

Alan N. Marcus		ISO - The value assigned to film or the setting of the imaging chip in a digital camera. This number tells us how sensitive the film or chip is to light. The higher the number the more sensitive or "faster" the film or chip setting. ISO is an abbreviation --International Standards Organization. Based in Switzerland, the ISO maintains standards used by science and industry. f/number - A number used to indicate the size and light-passing ability of the lens opening. We adjust by changing the aperture size. Most common f/numbers are f/2.8 - f/4 - f/5.6 - f/8 - f/11 - f/16 and f/22. f/2.8 passes lots of light, f/22 is a tiny aperture passing a feeble amount of light. Focal length - The distance from the camera lens to a point behind the lens inside the camera where the light rays come to a focus. If the distance is short a wide-angle view results. If the distance is long, the image obtained will be highly magnified. Aperture - The opening in a lens system through which the light passes. The diameter of the aperture in modern cameras is adjustable. The number value assigned is calibrated in f/numbers. Exposure - The quantity of light allowed to act on the film or digital chip. Too much and the picture will be over-exposed, too little and the picture will be under-exposed. Exposure time - The camera shutter is a gate that block light from acting on the film or digital chip. We press the shutter button and the shutter opens briefly. The length of time, usually measured in fractions of a second, is the exposure time. Etc. You must ask or pick up a book on the how and why of the camera. To love this comment, log in above May 06, 2011

John H. Siskin		Hi Varun, This article might help: www.siskinphoto.com/magazine/zpdf/basic.pdf It is also hosted here at BetterPhoto somewhere. I hope it helps. Thanks, John Siskin To love this comment, log in above May 08, 2011

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