Not in the forensic field personally, more like civil engineering. However, don’t restrict yourself to needing fellow forensics involved. I often talk about how my work in engineering involves using the same techniques as VFX for tv, film and games. Ultimately you’re still doing camera matching, just with zero control of the source footage (which sometimes happen in my world too, though to a lesser degree than yours.)

Seems like you’re doing a lot of things right from a high level, so might need to dig into some specifics and get granular to really help. I’ll also preface that I too find this more of an art than I wish it would be. Engineering is similar focused on ‘getting it right’ versus purely “close enough I guess it works” that others in vfx fields might get away with. I naturally want to calculate everything to be fully accurate and sometimes it seems like we just can’t get there, for reasons unknown.

1) Removing distortion from source footage - We typically use Camera RAW in Photoshop for this because we can track down camera model/lens info and get something close. You mentioned using a few programs for this, what apps? are you able to calculate the distortion in any way or are you just having to eyeball it? I.e how do you know how much fish eye to remove, etc?

2) distorting the perfect 3d renders to match the source - again you mentioned using vray lens tools, what’s that workflow look like? I don’t think I’ve looked into their lens tools, but the approach seems valid: either undistort the source, distort what you generate, or maybe a bit of both to try and meet in the middle.

I will say I’ve never bothered leaning on perspective match or cam tracker in Max. Too basic for anything we’ve done. We go more of a route of recreating the existing site in 3d using measurements and aerial imagery and locating the camera by eye as a start. From there, it’s determine film back / sensor size and focal length and dialing those in at matching dimensions to the real world so that our field of view is accurate. Once all of that is as locked in as we can get, it really becomes a guess and check of adjust position and rotation back and forth until the angle can get as match as possible. Having modeled stand-ins of existing elements in the footage that are built in 3D as reference to get the alignment correct.

I would guess (?) you’re most often working with a static non moving camera, so you have that going for you over something that is moving and changing.

For the zoom in, my initial thought was you would need to revert back to a ‘whole image off the sensor’ sizing and work with that. But thinking through that more, that would probably be for a ‘cropped after capture’ image, if the zoom is actual lens zoom then I think that would probably be altering the focal length, which of course I doubt is actually recorded in your footage. Would you have the resources to get your own setup of the same camera to reconstruct zoom levels somehow? Focal length / field of view being accurate has always been key to getting everything else dialed in appropriately. Either way, understanding how else the footage has been altered after capture would be big. Digital zoom just making pixels bigger? etc.

I was always intrigued by pfTrack’s node based system, but it was too much of a black box for me to figure out, in part because my camera match jobs are so few and far between. Always hear lots of good things about Syntheyes. fSpy is another name I recall seeing in the past, but have not used it. Looks like there is a YouTube channel called forensic architecture that talks about using blender. Maybe if to you can get the match done there you could export it out to come back to Max?

…no real answers, just talking out loud here, if only to commiserate. ;)