Learning all the time: exposure.

I have recently begun to undertake a course which will eventually give me a diploma in photography.  Bizarre that I got my first SLR just over a year ago and now here I am taking it seriously enough to consider a qualification in it.  I have always played safe with exposure and stuck to using the aperture priority setting on my camera.  The setting is AV on my Canon camera and it allows you to control the aperture whilst the camera takes care of the ISO and shutter speed.  I love portraits with a shallow depth of field so this has always given me results I am happy with.

I have been challenged by my course, however, to begin shooting in manual.  Manual, or M on the exposure dial, allows you to control ISO, shutter speed and aperture, as well as other variables such as white balance. It really is a challenge to get the correct exposure.  You can think of the aperture like the pupil of an eye.  In bright light it needs to get smaller and in low light it needs to be wider.  The shutter speed is obviously the speed at which the shutter fires and the longer it is open the more light it allows through to the camera's sensor.  You need a fast shutter speed for bright light conditions to avoid overexposure and a slow shutter speed in darker conditions to allow more light onto the sensor.  ISO is basically the light sensitivity of the sensor, a setting which harks back to film photography where you would choose film with different ISO for different lighting conditions.  A low ISO such as 100 is perfect for shooting outside on a bright sunny day whereas a high ISO is needed where light is scarce.  My camera's ISO capability goes up to 12800.  

The challenge of all this technology is marrying these variables together to achieve the perfect exposure.  I am having some IT difficulties at the moment but as soon as I can I will post some of the manual shots I have taken and you can judge how I am doing.

Happy shooting.

Jo