I'm trying to photograph a line drawn with a laser during a dark overcast day. My basic understanding is that 555nm is brightest in daylight and 100mw+ is strong enough to start a fire. So, I want something that is less than 100mw. Am I on the right track? Is this simply not possible with this low of wattage? I would ideally want something that I can easily mount to a surface. Can you recommend any online stores to buy this from?