Well, what I thought was a simple question has certainly given me a lot to think about!!! Thanks everyone with your ideas - that's one of the things that I love about this forum, the fact that there is always someone out there who can guide you in the right direction.
Now, if it would stop pouring here in SE Queensland then I might be able to actually try out the QHY5!!!
Cheers,
Mario
PS Please don't tell the people at the Queensland Astrofest that I've just bought a new piece of equipment as I'll get the blame for the rain!!!
