Back in the heyday of the nightvisionforumuk, following the discovery by a chap in Australia, we were improving them no end by converting them to what became known as the Extreme by removing the stock lens and fitting an M42 Pentax Takumar camera lens.. 55mm for rats n rabbits and a 105 for foxing. I got SRB Griturns in Dunstable to produce the adapters.
This coincided with the Osram AS LEDs coming out and resulted in a seriously good, camera quality image giving good detail out to 100’s of metres. The ability to close the shutter right down gave a good daytime picture too….
The weak point was the shutter petals meaning .223 was about as big as you’d want to go… I shot a lot of foxes with them on the .17 Rem and .20Prac.
Still got one with a 50mm lens for the air rifle or the Finnfire
Sadly, you had to hunt for a lens in good condition but they were about and could be serviced by Dave Boyle at the Camera Repair centre in Bletchley for a very reasonable rate. He used a slightly thicker grease on mine to make them a bit more resilient.
As mentioned above, the Pard008 really put paid to it.
Photons go for about £70-£75 at auction.
As it ‘’appens , I tried to zero one on a mate’s air rifle this morning but ran out of vertical adjustment


In the dim and distant, I have taken one apart and shimmed the corners of the camera board to get it to point in the right direction it was that far out of alignment.
Cheers
Fizz