Samyang 8mm Fisheye Lens
There was a slight problem, in that the studio is very narrow, and long. Taking photos in there even with a decent wide-angle wasn't going to be pretty... So, as everyone knows a fish eye's view of the world is far better than reality anyway, I got hold of a Samyang 8mm Fisheye, which you can get with the respective fitment for all of the leading (still) camera brands.
You can find these for just over £200 new - something I wouldn't have considered worthwhile a few months ago as we do next to no paid still photography work, but since Canon started releasing recent models with HD video capability, having a fisheye on hand for more creative video projects is kind of a bargain at only £200. It would cost thousands, if possible at all, for us to purchase a suitable HD video camera which could accept a fisheye lens. Most cameras at the pricing level a studio our size can feasibly own (rather than the higher spec equipment you would typically rent on a per-project basis), generally don't even have an interchangeable lens - you are stuck with a 72mm filter mount to screw a 0.6 wide angle extra lens onto, costing £300+ and giving such a minimal inprovement in lateral range in reality.
I've posted some photos of our studio, which were quick snaps in low lighting (it was actually dark outside but the camera was set in lamer mode and so auto exposed a long enough exposure to see the blue skies underneath the darkness), and the obligatory 'shot of my dog', to give you an idea of the wild distortion and ultra close focusing (30cm) of this dang thing.
The lens looks like it was designed in communist Russia, and I believe they are made in Poland (though this may not actually be accurate at all), the build quality is extremely solid and it feels like a more expensive piece of glass than it is. It's fully manual, including iris and focus, but I don't bother with any of that stuff, it's pretty much point and shoot left on the widest aperture and a mid-to-short focus distance as the depth of field is so immense due to the short focal length.
I feel I should offer up some kind of mark out of 5 after my mini-review, but let's just say, if I had a choice of keeping the lens, or having my money back, I'd keep the lens.

