I am a professional photographer. It is very complicated with a lens to focus. 
Oh my goodness! I do photography for fun and I don't know much about it at all. I was actually looking today to get new lens for my camera! I couldn't decide if I should spend the money to get new lens because I am happy with the lens I do have and am not sure if buying these new lens would really make a difference in my experience taking photos. What camera do you have?
My camera was made in 1987. Standard lens mount. Which is very light sensitive. 
See! I see you saying these things and I am not quite sure I know what you are saying. Sometimes I feel as if I need to take a class just to fully understand what I'm doing with my camera and to really put it into its full capabilities. So if your camera was made in 1987, what made you choose that camera over newer generations?
Since it is a Canon EOS camera. The choice of this camera is due to that it can made a career in many possible areas of business.