No, it isn't. Jimmy Carr , the comedian, was acquitted of using the phone when driving because, according to his evidence, he was using it as a 'dictaphone' to record thoughts on scripts. When this topic came up before on AB, we researched the law and discovered that the law was worded to forbid the use of telephonic devices only and using the phone as, for example, a camera , was no more illegal than using a camera was.
Of course, if you use a camera when driving you may be committing an offence in that you may not have proper control of the vehicle.