[Tamanegi65]

I’ve read that article – mainly it discusses the Ultimatte and Chroma Key keyers and what they can do. It does touch briefly on paints – but doesn’t have any info to help me decide which paint to use for keying with Keylight?

[Tamanegi65]

I think that’s always been a setting when queueing a render – whether or not to use the current cache or rerender everything. I’m not in front of AE at the moment, but take a look through the render settings, pretty sure its there.

[Tamanegi65]

I really haven’t noticed it too bad either – but there was one outdoor shot where we composited a building into a field and the shot began with a long dolly/pan to reveal the building. I was tracking the ground and other FG objects, as well as large tracking markers we put where the building was to go about 80-150 feet away, as well as far distant (300-1000feet) buildings in the background. I had a real hard time getting a clean track and I’ve been wondering ever since if it was due to lens distortion. It was shot with a VariCam – just stock lens I guess (not a prime, etc.)

So in general do you just track and not really worry about lens correction unless it seems to be causing problems?

[Tamanegi65]

I was just thinking some more about this – what about a green screen shoot? Yea, I put in tracking markers, but I don’t usually make sure they are in a line. I usually measure their location and take some picts on set for reference later – but typically there won’t be anything in frame that has a straight line….????

[Tamanegi65]

The .ma importer in AE is buggy though – seems it never gets the zoom factor right on the camera. Anyone know of a workaround other than just adjusting it by hand until the 3d markers match the rendered sequence? I always put in a few extra nulls in maya just so I can correct the AE zoom factor. Not too big of a deal if the lens was fixed – but would be a pain if the camera zoomed while shooting.

[Tamanegi65]

When I first started playing with 3D renders in 1993 everyone made such a big deal about rendering in fields – how much smoother and more fluid the motion was. It seemed that rendering progressive was considered amateur back then.

Now – I do a lot of VFX work and compositing and motion graphics – all of it would be a nightmare if I had to deal with fields – I do everything progressive. The only time fields come into play is when I work with 24p footage and need to do 3:2 pulldown at the very end of the project to get it to NTSC.

That all said – it seems the industry has flipped on whether true interlaced footage (and or CG rendered elements) look better as progressive then fields?

I totally don’t disagree with anything posted here – Its more of an observation and wondered what other people thought of it?

[Tamanegi65]

Check out this book: “Matchmoving The Invisible Art of Camera Tracking” by Tim Dobbert, published by Sybex.

[Tamanegi65]

Ah, ok – makes sense. Thank you.

So, is there any use to shoot a calibration card with a grid on it during the shoot?

And also – if I re-write out my footage after being corrected in the tracking software and render my CG stuff with the camera it creates – do I really need to reverse correct the CG elements to composite on the original plates? Couldn’t I just use the corrected footage? Wouldn’t it look a bit cleaner without the distortion? Or does the correction of the distortion create more artifacts due to smooshing pixels around?