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| IMHO, the only safe way to reliably deal with lens distortion is to take a couple of mins out and shoot a grid with the same camera/lens (and even down to the focus setting) on set. most grip trucks have a 4x8 piece of plywood and most kinkos can print & laminate you a 4x8 grid to clamp to it. it's not as good as the laser etched grids that can be bought but it's a reasonable facsimile. watch out for glare off of that lamination. I like the WarpD module in 3d Equalizer for solving the distortion, but most tracking software has some equivalent and surely the values could be adapted for optics compensation. Nuke's lens distortion tools are pretty good too. the good news is, a lot of the modern camera/lens combos are darn near rectilinear. an 18mm on a Red Epic is surprisingly straight. it's when you get into the old pawn shop Nikon glass stuck on a 5D that you start to have to worry. oh god there was this one tilt shift lens that made my life very difficult on a few shots... adobe has a pdf floating around (i think buried in the photoshop or lightroom stuff somewhere) that introduces the idea of "lens profiling," which in theory could automate some of this type of stuff, and possibly be driven off of metadata. the way they were wanting to deal with the distortion seemed pretty cool - you could hold up a smaller grid and take 9 stills, with the small grid held up in the lower left, lower center, lower right and so on. photoshop would then stitch them together and solve the distortion for the whole lens. interesting! On Fri, Jun 29, 2012 at 9:47 AM, Chris Meyer <chris@crishdesign.com> wrote:
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