Go to View|Camera|Properties and UNcheck "Perspective view."
Well that's very exasperating, because I need Perspective view to make it look real, but TC is slightly fooled by the angle of the view, so the center of the View is usually a bit left of the center of the object, so I have to include more background than desired.
Guess I'll have to experiment with turning Perspective view on after I specify the view.
Nope... that doesn't work (the object ends up too small).
TC Pro Platinum 2018, 2017, 2016 & 2015 (all with LightWorks & RedSDK) & V21
System: i7-5820K @ 3.30GHz, ASRock X99 Extreme4, 16GB DDR4-2133 RAM, Gigabyte GTX 970, Samsung NVMe SSD 950 (256GB), Windows 7 Pro (64-bit) SP1