[White Rabbit]

I have been imaging m83 and have 4 hours for each channel but I forgot to take flats for the red channel. Is there anything I can do or should I chuck the lot?

Second question, at the moment I've been taking the same amount and length of subs for RGB (unbinned) as for my lum. If I bin my RGB what length should my subs be in relation to my Lum subs. I'm using asronomiks LRGB type 2 filters.

Thanks
Sandy