I have a sony DSC-P200 and i am trying to manually configure the exposure setting and there are only 2 setting that i can go to and that is 2.8 and 5.6. I dont know how to chose the F value for the right settings. Some times when i put F as 2.8 then the picture gets brighter. I know F is the aperture value but how does having a smaller aperature value makes the picture brighter. The smaller the f-stop value, the larger the aperature. This means the blades of the aperature itself are closest to the outside of the lense. When the camera is "stopped down", and the f-top is increased (to 5.6 for example), these blades close in making the hole through which light can pass smaller. You should be able to do an experiment on your camera if it is capable (requires a half-press shutter release for focus).
Set it to 5.6, and turn the camera towards you (quite close) and look straight into the lense. Press the shutter button half way down, and you should be able to see the aperature close a bit inside the lense.
A smaller f-stop (2.8 for example) will produce a brighter image (depending on the shutter speed), but will reduce your depth of field (the area in focus). A larger f-stop will increase your depth of field. Of course there a thousand other factors to consider - I would suggest doing a search for online tutorials - you will be able to make the most of your camera in a short amount of time. go here> http://www.dpreview.com/learn/?/key=aper... | 