Where or how do you find the keyframes for properties in the Dope Sheet? I have some keyframes for the Radius of DoF on the camera. Let's say I want to change the interpolation on the value changing from Linear to Bezier or the other way around. 

I know I have show only selected in the dope sheet, but otherwise it gets way too cluttered, and would take minutes just to find it, and I'm not sure if it is there. 

How do I find the keyframes of properties so that I can edit them?
You can also filter by type, in this example I have turned off all dope sheet keyframes except camera:



To change interpolation of keyframes select the keyframe that you want the change to occur after, then press the T key.

However changing interpolation will not be apparent without showing the animation in the Graph or F-Curve editor.