Correct exposure using a greycard

Exposure is an issue, particularly if you don't have a light meter.  While DLSR's have internal meters they don't always give the results that you want.

The following blog explains the use of a greycard:
http://photosmadesimple.blogspot.com/2007/12/technique-18-gray-card-exposure.html

Apologies for not updating or keeping the blogs simple but I've had to deal with an operation and food poisoning in the space of two weeks.