I need to fix an iris change in the middle of a shot. I'm using color effect and setting key frames but I'm not getting the best results. What do others do?

 Count the number of frames that define the actual iris change. Place an add edit at the halfway point. Apply a centered dissolve equal to that duration and color correct each segment appropriately. Done.

Thanks for the advice Larry. That works for me some of the time but I just tried 3prongs Flicker Fix and WOW! Fast, effective and cheap!

 Yeah, I've been trying to get our people to acquire 3Prong for some time now. Maybe soon....

Ok, I've been waiting for ages for someone to ask this, cause I have the perfect answer.

But you have to have Sapphire.

In the TIME tab, select 'S2_FlickerRemove'.

Apply this to your shot.  Pick an area of the shot that doesn't change (i.e no one walks in front of it etc...).

Reize the OnScreen widget and place the box over that area.  If the shot is moving, keyframe the box.

Select all keyframes, park on the part of the shot that you want to match in Exposure and press the 'Set Hold Level' button.  The Hold Level parameter should change.  And Render.

This can be a little quirky in HD.  So if you press the button, and the parameter doesn't change in munber; or when you render the exposure goes insane.  You're best off staring again, and reducing any unnecessary tweaks.  If you get it right it can iron out all exposure changes.

(I once had a shot with 12 changes - some sharply on the 2nd field! - due to a faulty camera and this made the shot look perfect).

My absolute best tip!