The basic exposure thread

[Marko]

Hi Members,

I wanted to put out a thread to explain basic exposure and have people give their own input as well. Basic exposure is a stumbling block for newbies; one that they must understand in order to progress.

I'm copying and pasting some stuff from previous threads and members should feel free to do the same. When it comes to basic exposure DO NOT USE FLASH WHEN YOU ARE LEARNING. Flash is a level 2 element turn it off. YOU MUST fully understand basic exposure before adding a new variable.

Here are some notes on basic exposure.

All a camera is, is hole with a flap over it. When the flap is lifted light hits film or a sensor. On modern cameras, depending on the setting you use, the camera's meter suggests an exposure. This suggestion is good one in the following condition;

- When there is a good representation of light and dark tones. This is called a normal scene

AT THIS POINT WE MUST SAY THAT THE CAMERA IS BLIND. IT DOES NOT KNOW WHAT IT IS LOOKING AT BECAUSE IT HAS NO BRAIN. ALL IT DOES IS AVERAGE OUT THE TONES IT SEES AND SPITS OUT AN EXPOSURE. ALTHOUGH THIS IS NOT INTUITIVE (FOR COLOUR PHOTOGRAPHY) THE COLOUR MID-GREY IS THAT MIDDLE TONE THAT THE CAMERA USES AS THE AVERAGE.

This example below is perfect.

This is an image of snow by casil403 (thx in advance)
Snow is white but this shot is grey - BECAUSE THE CAMERA IS BLIND. It has no idea what it is looking at so it averages out the white snow and turns it grey.
There is only white in the scene, so it is NOT normal.
Therefore if you use the meter's reading in this case you will NEVER EVER get white snow. You have to make adjustments to the meter's reading.

That's the end of the first note - More to come.
Thx - marko