View Full Version : Auto Knee?

07-05-2011, 09:08 AM
In the limited testing (and shooting) I've done, I have found manual knee settings can be hit or miss - if you're set correctly for the lighting and exposure it helps with highlight detail, but it can also mess with other parts of the image. I think I understand how manual knee control works, and if I have time to set up a shot to this level of control I'll do so. But most of the time that's just not workable for me.

So that leaves me with the Auto setting. I've been happy using auto so far, but I would like better understanding of this setting so I can possibly predict when it may break down. Does anyone know what the camera is measuring and/or calculating when it sets the knee in Auto? Am I correct in assuming that it is just changing the slope, since there is still a manual set point? Is the camera basing it's decision on the picture profile settings (gamma curve) when calculating the knee? Or is it somehow evaluating the metering in the scene? Or both?

Sometimes in the field you just have to accept blown highlights. I'm just trying to get a sense of what situations might warrant taking the extra time to try a manual knee setting.

07-05-2011, 09:40 AM
If you have a variable power light you could try getting a cylinder of white paper and side light it

As you turn the light up watch the tonality