Blaster6 wrote in post #16604542
First of all -- great shots! More than anything else I love how the colors pop. I am impressed by how the photos look but not really that shocked a 6D was used. If you can't sell at least one of those... well I don't know why.
After reading this entire thread I am convinced some of you don't even know why a cross type point is better.
As simply as possible, a focusing point works best when it sees something contrasty at a 90 degree angle to the point. Think of your focusing point located by the little boxes looking like this ---> [|]
Put that on a wrinkle in a jacket, a strap going across the chest, or pretty much anything that crosses it and it will lock on. The higher the contrast the faster it will lock. If you try to focus on something that only has contrast vertically the outer points are going to have trouble. I don't see an extreme lack of horizontal contrast in these photos.
Now what if you are trying to focus on a row of fence posts in the distance that look like this --> IIIIIII
That is where the cross type sensor that looks like this will help ---> [+]
Since it can look for contrast either horizontally or vertically it should, in theory, lock on twice as fast or twice as often.
Is the center point better? Yes, some might say twice as good. Are the outer points useless? Certainly not if you know how they work and understand their limitations.
As for AI Servo & AI Focus -- Servo "expects" a moving subject & Focus "expects" a still subject. Use them in the wrong situation and the focus may freak out a litle. The AI stands for Artificial Intelligence so the focus trys to predict where the subject will be in addition to where it currently is.
Sure, you can spend an extra $1000 for the 5D3 or you could get results like the OP if you understand what the 6D is really capable of.
Good post. but sometimes it's not that easy. If you have contrast in the ||||| orientation, and you wanted to focus on with the outer points, you could use the turn the camera to a vertical position, focus, and then recompose, but what if your subject was moving, or you didn't have much time, or you moved a little therefore your DOF was off. So while you understand the limitations, sometimes it's very hard to overcome them.
Not taking anything away from the OP, those are very nice shots, but they are not terribly taxing on the AF.