Poser uses the width, always.

And as for the 12.7 versus 12.75, I tested this with some extreme precision. I buit a procedural shader for my environment sphere that created little bars all around the equator. I had white bars every 10 degrees, green bars every degree, and black bars every 1/10th degree.

I then positioned my camera at 0 0 0 and rendered with dozens of focal lengths. This was how I arrived at 12.75.

If you compare the apparent fov from Poser with that of a 35mm SLR, Poser's focal length is just about a 1.414 crop factor, as far as I can tell to a precision of 4 digits. What I mean is, Poser at 100 mm looks like an SLR at 141.4 mm. My guess is that somebody did an extra sqrt somewhere that they should not have done.

I am building the camera roll pitch yaw right now. Will be done shortly.

I'll let you guys figure out the portrait/landscape problem.

By the way, in order to deal with that, the camera exporter needs information from the film exporter. And I suspect that the material exporter is going to need information about the world transformation should we decide to actually convert Poser units to meters so that other content can be combined with Poser content in Lux. (Unlikely, though) The material exporter deals in Poser inches for bump and displacement and the P node. (Firefly is entirely based on inches.)

---

Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)