Auto Focus lights on DSLRs - do they cause any problem?

[Welly]

I gave my Nikon D40 DLSR to my friend and recently he asked me how to turn off the AF light on the front of the camera.

I pointed out that it only comes on in low light conditions to assist with the AF and that I have used that camera for photographing trains without problems as it is nowhere near as bright as flashes.

Can any train driver on this forum tell us if they have any problem with AF lights on cameras or not please?

 

[richa2002]

I would turn it off as it pretty much serves no purpose when shooting trains which will pretty much always be illuminated by something more than a puny AF light. Whether it's natural light or artificial light. If your AF light is bright enough to provide more illumination than the lighting already available, then it is probably dazzling for the driver.

On the flip side, the whole 'no flash' thing does seem a little questionable now that drivers have to put up with insanely bright LED signals and the new-style 10 trillion candle train headlights. Perhaps it is the unexpected nature of a flash that is the problem though. Regardless, as a photographer, I can't imagine any situation where I'd want to use the flash, especially on the railway.