For the astrophotographer this is annoying but that's all it is. There are bigger events at the moment to get upset about. I share your frustration Nik, for I too was looking forward to some great conditions on Saturday night. My subs all turned out with a brown cast due to the smoke. This is just something we have to contend with this time of the year. I understand why they need to burn, it's necessary to reduce the fuel and there are limited days when they can do it. My astro fun can wait for another night - it's not important and doesn't match up to something done to reduce the risk of future bush fires.