I’m a frequent visitor to parks, zoos, museums, and gardens and so there are many opportunities to photograph strangers. I typically focus on the children or families for my shots.

So in these situations, I almost always ask first. It might be surprising that this exchange is often non-verbal. I always make eye contact with the parents/guardians and greet them with a smile and a gesture asking for a photograph. A quick return smile and a nod is often all that is needed. This happens very quickly. Still, if a scene unfolds unexpectedly and a shot must be taken first, I at least let the parents know (either I show them the shot or I thank them or I compliment them or their children) that I took the shot.

I’ve never had a shot declined or argued over doing it in this fashion. Granted I don't go trying to shoot controversial type images. But I think people are intelligent enough to realize when a scene is photogenic. In fact, I typically hear (after I shoot a few frames) another stranger coming up to me and saying “that’s a great shot” – meaning the moment in general and not my shot in particular. I always find it rewarding (and sometimes very informative) that a few comments and a few images can make for a warm (yet brief) encounter with a total stranger.

Sensitivity and professionalism are paramount. If you act and look professional (not necessarily as in a “professional photographer”), people will treat you as such. With children and families, I think it is better to ask and shoot with a normal/wide lens up close than to not ask and look suspicious from afar with a long telephoto – even if the subject doesn’t see you, others around you will.

I’m a parent too and that’s just common sense IMO.