Is this called digiscoping? (1 Viewer)

The following picture was taken today using a D2X, a 200-400 / 4 zoom lens set at 400mm, with two TCs stacked between the camera and the lens - the TC-20EII and the TC-17EII. The shot was taken in high speed mode with a crop factor of 2. The total focal lenght was:
400x2x1.7x2= 2720mm. The tripod was a Gitzo 1348 and the head was an Arca Swiss ball head. The picture was not cropped, just a bit USM was applied to the small image. The exif does not report the TC-17EII, therefore only the TC-20EII is reported (Nikon didn't think that soemone will stack two TCs on top of each other...). The picture was taken MF, with the VR turned on. Quite amazing for so many elements of glass that were used. Obviously, it is not a quick and light-weighted solution. I'll stick to my CP4500 / 8400 and my spotters for real digiscoping work, but I was curious to try this combination.

Stacking T/Cs is an old standby if you use top quality kit, but it was usually tried with a prime lens so your zoom must be an excellent lump of glass to hold up the quality so well.