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LBgirl36
Guest
If I am on f4.0 and I switch to 2.8, is that letting in more or less light, and how much? How about with 5.6? =]
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.fired77
Guest
The smaller the number, the more light comes in. It's usually referred to as a "large" aperature (i know, confusing.)..you can also say a "big" aperature. Big/large in reference to the size of the aperature, not the number, which is small. Example= at f/4 the "hole" is smaller than f/2.8. So, at f/2.8 more light is let in because the "hole" is bigger.
naturally, 5.6 is a bigger number, so less light is let in.
The difference between those numbers- 2.8, 4, and 5.6 is called a "stop". You may have "EC" settings (exposure compensation). The +1 indicates a plus one to a stop of light, while setting the 'EC' to -1 would lower the exposure by a "stop". So, if a properly exposed pictures requires f/4, but you set the EC to -1, it would change the equation and make the aperature f/2.8 because it is one stop below f/4
To complicate things more, this also means when you change the aperature- say from 4 to 2.8 (more light), you can then change either the ISO or the shutter to compensate for more light. To compensate for more light, a faster shutter will need to be used. Because it is one stop higher, you will need one stop of a shutter to compensate. Or, you can change the iso to a lower number- say, from 200 to 100. ISO goes by one stop at a time, so 100 to 200 is one stop, 100 to 400 is 2 stops..etc.
The math gets easier the more you get comfortable.
naturally, 5.6 is a bigger number, so less light is let in.
The difference between those numbers- 2.8, 4, and 5.6 is called a "stop". You may have "EC" settings (exposure compensation). The +1 indicates a plus one to a stop of light, while setting the 'EC' to -1 would lower the exposure by a "stop". So, if a properly exposed pictures requires f/4, but you set the EC to -1, it would change the equation and make the aperature f/2.8 because it is one stop below f/4
To complicate things more, this also means when you change the aperature- say from 4 to 2.8 (more light), you can then change either the ISO or the shutter to compensate for more light. To compensate for more light, a faster shutter will need to be used. Because it is one stop higher, you will need one stop of a shutter to compensate. Or, you can change the iso to a lower number- say, from 200 to 100. ISO goes by one stop at a time, so 100 to 200 is one stop, 100 to 400 is 2 stops..etc.
The math gets easier the more you get comfortable.
E
EyeCandy
Guest
Going from F/4 to F/2.8 lets in more light (twice as much) - the opening gets bigger
Going from F/4 to F/5.6 lets in less light (half as much) - the opening gets smaller
Going from F/4 to F/5.6 lets in less light (half as much) - the opening gets smaller