Posted by rick oleson on September 22, 2003 at 13:39:43:
In Reply to: help! posted by esther on September 22, 2003 at 12:57:52:
First, the Canon AE1 has a clever little button for overexposure, located on the left side of the lens mount... pushing this button gives you a +1.5 stop overexposure: http://www.mir.com.my/rb/photography/companies/canon/fdresources/SLRs/ae1/basic6.htm
Your other easy way to get a controllable over- or underexposure is to change the ISO (ASA) setting on the shutter speed dial. Setting it to a lower number will give you overexposure, setting it to a higher number will give underexposure. For instance, if you have ISO 200 film loaded, setting the dial to 100 will produce +1 stop overexposure and setting it to 400 will give -1 stop underexposure. The full range of tone from near-black to near-white in a photo is about the range of -3 to +3 stops from a standard reading, so if you want the card (whatever its real color is) to look white, go for 3 stops of overexposure.
The relationship between ISO numbers and stops is: doubling the ISO number equals a change of one stop. so from ISO 200, +1 stop overexposure would require setting the dial at 100; +2 stops would be 50; and +3 stops would be 25. Going the other way, 1 stop of underexposure would occur if you set the dial to 400; 2 stops would be 800, and 3 stops would be 1600.
You can also take your lens off the "A" setting and select the apertures manually, but it's more convenient in the AE1 to adjust the meter and leave it on AUTO.
rick :)=
end of archived message