Matching an AE 3D camera and 3D comp to the perspective of an existing photo

Question

I searched the forums for "3D," "camera," "match," and "perspective," but I didn't find the answer I'm looking for.
I have a 3D comp I have created in AE. Animation is all done of layers moving in 3D. I have a still photograph that I want to composite my 3D comp into, and I need to get the perspective to match as precisely as possible. I do not need to move/animate the camera. Just a simple still shot for my background plate and I want to "place" my 3D comp (or the 3D camera looking at the 3D comp) so that it will animate on top of the still background and match in perspective.
What technique should I use to get these elements to line up? I tried to "eyeball" it by just pushing the 3D comp around in 3D space and rotating it and the camera, but I don't think I was ever going to get it right. Too many variables. Seems like there should be some way to do this "properly." I'm using AE 7.0 and Photoshop CS2.

Answer 1

Hi Rick,
Thank you very much for the response and for providing the camera and 3D solid data. Quite nearly a perfect match. Thank you, thank you thank you.
Regarding focal length / angle of view. We're talking about two different things. You're absolutely right that focal length is "only a cropping tool" and does not alter perspective. However, angle of view is very different from focal length and absolutely changes how edges converge at vanishing points, etc. But I now see that we we're talking about different things.
For what I was doing, I definitely needed to position a 3D camera and work with a 3D comp. Corner pin would not have done the trick. I wish it had been that easy.
I'd love to know what process you used to arrive at this combination of camera position and 3D solid position. I would push things back and forth, up and down, here and there, and I just wasn't getting close. Curious to know what your method was. I was trying to be intelligent about it (figuring out the horizon line... making sure the camera was on the same plane... tilting the camera up slightly... placing grids in 3D space to try to get a match... etc.) and it just seemed to be a nightmare. I've been working in 3D for over 15 years and know what I'm doing, but I couldn't get over how difficult this was. Just seemed like way too many variables. I'm much more of a "figure it out the correct way" kind of person, and I don't do well with "guesswork." If you have some thoughts on how to simplify the effort, I'd love to hear them.
Thanks again.
BTW... I look forward to upgrading to AE CS3 and PS CS3 Extended just as soon as I can. Until then, you may hear from me again on this topic.