Long exposures - risk if damage to sensor?

[steveatesh]

Me and a photography friend were out taking shots of a local landmark the other evening, hours of darkness.

After we’d been there around 15 minutes another photographer turned up and started to tell us he needed the scene as he was taking shots professionally as a paid job. It was obvious our presence wasn’t welcome, fancy having the temerity to take photos of landmarks!

Anyway, We were relying on a very low ambient light, so we’re experimenting with exposure times.

I took several shots of around 60 seconds and we were discussing the next shots when the professional interupted us to give us advice, which was that we shouldn’t take shots in excess of around 25 seconds as it would risk overheating the sensor and damaging it.

Anyway, we finished our session off and got some good results as mere amateurs.

My question though is does taking long exposure shots in excess of say 30 seconds damage the sensor, and if it does why does the camera have a bulb setting?

I’m sure I’ve seen very very long exposures taken by professionals, say Star trails. I took a 15 minute shot during blue hour with no apparent damage.

Was he right, or was it just bks?

[steveatesh]

Thanks everybody, I thought it sounded bks, I can carry on with my long exposure shots without a care in the world then