Virtually all our travel is dictated by what I feel the need to photograph, and now its my wife's turn . I've booked two winter workshops to Iceland and the Lofotens for us both- because that way she won't be worrying about driving in difficult conditions. Whilst we will both enjoy photographing in snow and ice, the biggest objective for her is to see and photograph the aurora borealis. She usually uses a compact, but here she'll be using a 5Dii that till recently was my prime camera, working from a tripod. The question is what lens to put on it. She's been loaned quite a bit of stuff by kind friends and one candidate is a relatively elderly but little used 28-135 EF IS. She'll also have access to a 17-40 L from my bag if she needs anything wider. Alternatively I can buy her a 24-105L and sell it on after the trips. Question is whether there will be a big difference in IQ. I know the 24-105L has better IS but of course all the Aurora work - which is where mainly she'll use the 5Dii - will be tripod -based so IS will be switched off anyway. I'm a bit torn, can you help please?