All Change!
After new standards of safety and operational efficiency were adopted by Network Rail, Pentax lenses have been selected as the eyes of the network's Driver Only Operation CCTV system.
CCTV cameras acquire images from the length of the platform and project them onto a colour monitor on the platform next to the driver's cab.
New rolling stock saw its introduction some 10 to 15 years ago. In order for the new trains to be compliant with safety requirements, visual surveillance needed to be upgraded from the existing black & white system.
According to Tim Walton from project engineers C.I.S. Ltd (Consultants for Integrated Security) in High Wycombe, it was vital to have the flexibility and image quality offered by high-resolution colour monitoring, so that the conversion from slam-door rolling stock and the introduction of sufficiently capable remote visual surveillance would succeed.
"Environmental conditions and performance requirements meant that only higher end solutions could be considered," recalls Walton. "Exterior cameras and monitors must consistently operate in conditions of extreme weather and lighting variations. Interrupted or unclear images actually impact directly on safety and therefore are unacceptable."
The C-Mount 8~48mm manual zoom lens with video iris is startlingly good in low light conditions with its f.1 stop at widest angle, its excellent light transmission and high resolution. 
This is the lens of choice for the Hong Kong Railway System and has been used on many Network Rail and London Underground projects in the UK.
The second of an 8-phase rollout has been completed on 24 stations in the South Central area, in a scheme that will eventually see in the region of 1800 cameras installed at project completion.
