I book a lot of sessions for kids outdoors - mainly in parks in South London. If the weather is terrible on the day the session is of course rescheduled, but that is rarely necessary. Until I was booked to photograph these little girls - I think we had to reschedule three times until we managed to book a day when it wasn't bucketing down! I met the sisters and their dad in a park in Dulwich and we had a great session - in sunshine.
