It is significant to understand what is meant by ‘signing space' with regards to a Deaf person. This is the area that provides for optimum viewing of signs as they are formed. As a general rule, signs stay within the dashed circle, allowing for the movement of the signs. The shaded area is for fingerspelling and you need to be careful that you are holding your hand still, not bouncing it as you spell.
Of course, if you are addressing a large audience, your ‘signing space’ will increase and, if you are talking privately with another person, this area will decrease.