It's a feeling of comfort when you reach a point in your exploration of photography, wether it be a hobby or a profession, that you no longer have to worry about calculating proper shutters, f-stops and ISO levels. Finally, after much trial and error, the technical part of this wonderful art form has become a wonderful instinctual process. Long gone are the days of wondering how on earth is the aperture going to effect the image. Lying on the road behind, are the days past of scratching your head trying to calculate the inverse square law (I1 x d12 = I2 x d22). Ah, the formula is magical isn't it? Easy as pie, right?