I don't know if I have the vernacular to accurately describe my thoughts, but I'm going to try....
The numbers I've been working with are Edge: 3 Middle: 23 for everything. I can't prove this, I admit up front I could be wrong, but the shape you chose for your capture areas matters.
We also know that there is some kind of "right lean" to Ambi.
If you pick 4:3, you'll get a picture, and if you pick 16:9, you'll get a picture. What matters is that you pick the correct location and factor in the "right lean." The "right lean" suggest that neither ratio is exactly correct. And I'll try to explain what that means.
Going back to my numbers: 3/23 (everything). This gave me a letter box shape and IMO, an extremely accurate TOP. My right was NOT accurate. I wanted to try Twat_The_Douche's right side numbers.
I tried Right 5/11, but kept the rest of my numbers 3/23.
First, "Right, 5/11" is significantly better that my 3/23. However the "Right Lean" showed up. What happened is, as I made the Right side more accurate is, the colors of heads no longer aligned with the tops of their heads. The color leaned (you guessed it) right.
What that means is, if Superman is in the center of the screen and his forehead is the top edge of the screen, the Ambivision leaned the skin color to the right. That means it didn't match up with his head. That's... SUPER frustrating.
It seems like as you make one side accurate, other sides slides into inaccuracy. And that's because of the dreaded "Right Lean!"
So how do you adjust the screen to make the right more accurate, AND keep the other sides accurate?????
I had to figure out some kind of compromise between my 3/23 accurate TOP and TtD's accurate RIGHT 5/11
Rather than bore you with the details of my trials and errors, based on my numbers and TdD's numbers, this is what I came up with:
Top: 4/24 Left: 3/18 Bottom: 5/27 Right: 6/11
I'll add my opinion on the dreaded "Purple Haze."
Purple Haze is a combination of two different things. First, everyone should color correct their Ambivision to their TV. That can be a huge PIA, but I don't think you can run the gammas and colors out of the box and have no purple haze. Second, if your capture area is to 'wide', you grab 'nothing' and Ambi reads that as purple haze. You need to tighten up capture area AND adjust your colors to reduce Purple Haze. Key word: REDUCE. I've got it small, but haven't removed it. And the place it remains- TOP RIGHT. Imagine that.
Why am I talking about Purple Haze when we are talking about capture areas? Because I had more accurate capture recognition ratios, but Purple Haze crept in. The numbers I listed helped reduce Purple Haze, but compromised accuracy in the process.
The whole project is a series of averages and compromises, broadly speaking- I'm happy with mine. Not "hyper" accurate, but every time the red Marvel card comes on my screen- I'm totally happy.
I've only run these numbers for a few hours, but I'm happier. I'll run them for a few days and report back my thoughts. Right now, I think I have a more accurate top and right and that makes me happy.