I consider myself a very amateur photographer but I do love fast lenses. However with fast lenses unfortunately my most common mistake is misjudging the depth of field of my subject! nothing more frustrating than taking a load of photos and missing that ever so slight depth of field that is just slightly shallow of your intended picture!
In this short video Mike Browne explores the mistakes most commonly made by beginner photographers, why not post your most comment mistake in the comments below?