Hi, Scott.
When i made that comment, i was probably thinking more of working with SLRs, and their faster lenses. I don't know that this holds true for the G2. But, with the N1 and a 50mm 1.4 or the 85mm 1.4, if your subject (for me, portraits, not macro) is close and you want to selectively focus on an eye, and have the rest of the face fall out of focus.... If you first focus on that eye, and then change the composition so that the eye no longer is set where the sensor is, you may have changed (very slightly) the distance between the lens and the eye. With just a slight rotation, that distance may change a matter of millimeters or a few centimeters. With an 85mm 1.4, depth of field is not forgiving of those minute changes, so you have to be conscious of keeping those distances equal. With the multiple focus point sensors of some cameras, that's a bit easier. But i don't really like to use all five sensors, as it requires using the joystick to navigate to them and the constant switching keeps me thinking about things other than composition. It's like playing a video game while photographing.... And, the G2 only has a center sensor, right, so you always have to focus lock and then recompose unless you like your subjects always in the middle of the picture....
So, as i said, it's less critical with an f2/45mm lens except at the closest focus ranges, and not at all critical with the 35mm or wider. I'd be careful with a 90/2.8....
These are just measures that can ensure more 'keepers.' It may also be the reason why there's such a thing as focus bracketing in the N1. For ex&les of the extreme with shallow depth of field, check Mark Tucker's site (
www.marktucker.com). He now favours a Canon 85mm 1.2 lens, and he shoots everything wide open. Focus is so critical with that lens that he can't even rely on the amazing EOS AF. He works manually, and has to bracket focus.... and that's with everything locked down on a tripod, and stationary subjects....
