iPad as camera - external hardware

[iRaynor SK]

Hello,

In future, I plan to get 4K camera. But for now, I want to record something with iPad. 4K cameras are very expensive, so I want to try it with iPad first.

Can you recommend me some lenses? And external flash, like iBlazr? Or something othet what I should use?

I have iPad Air 2, my computer is MacBook Pro Retina 15-inch Late 2013 (with nVidia GT 750M). I use Final Cut Pro X with Motion and Compressor. And HandBrake.

Thanks.

Lukas.