You are correct. The cutoff is actually closer to 1125nm.
So the SWIR is photographed using a fluorescent screen that upconverts SWIR photons into NIR photons. Physically, it is the anti-Stokes effect. The converter tube and screen are the CamIR Adapter, which is the same as the Edmund Optics version, which I obtained on eBay. I paid about 12% of Edmund's price!
(I believe this to be the cheapest SWIR camera setup in existence! ...and it was still too damn expensive. )
This is with the Cine Velostigmat 25mm/F1.5 (20", F/1.5, ISO1600)
With a Thorlabs 50mm SM1-mount lens (F/2)
Edited by Andy Perrin, 10 February 2017 - 02:31.