For a paid event, refusing to shoot because it rained sounds reasonable IF the event also stopped. Weather conditions dictate the fate of most outdoor sports. I say most because not all sports observe this rule. Golf, for one, does not and seasoned golfers play on come rain or shine except when there's imminent life threatening danger such as thunder and lighting. In one golf tournament here in Brunei, lightning struck Hole 18 at one of the popular courses, thankfully that did not mean the LAST hole ever for a flight.
Last weekend, I shot the
2008 Lexus Golf Classic where it drizzled on the second day right before the group photo and it got progressively heavier. My 5D and 24-70 got more than its fair share of water droplets from waiting for the group to get ready, I just put a towel over it. By the time my partner and I reached our designated Hole # for the individual flight photos, rain got heavier and we had a lot of equipment still in our Lowepro bags ... both 5D and D3 were out and about.
We had a problem that weekend far more dangerous than rain. The D3 was corrupting images and we lost about 21 photos from the registration and thankfully not one from the critical group photos. If you follow the link above, my partner Anthony wrote his piece about the incident.