Well the situation that tested me - and at which I failed - this weekend was a fashion runway show (Chattanooga Fashion Week) in which my daughter's designs were included. The lighting was very low, I used a flash to help, but focusing was a challenge. I'm sure my eyesight is not as good in low light. The lens was a Nikkor 35 - 135mm f3.5-4.5 which contributed to the challenge because of the relatively small maximum aperture. I think it is right that some "focus planning" is important - I could have pre-focused on more spots to have a better idea where on the lens barrel I should be at various stops along the runway; I should have used more power in the flash for a smaller aperture and more depth of field, etc. It seems the digital guys just set their cameras on ISO 6400, everything else on auto, and have auto-focus. They get great results but I don't think I would enjoy photography that way. I prefer to make mistakes and learn from them, rather than make no mistakes because I'm not really doing anything.