During photographic history a lot of focal ranges for zooms have been introduced, but it seems that, today, the most common "professionally accepted" ranges are very specific. Mainly 24-70mm and 70-200mm (35mm equiv.). It's no coincidence that Panasonic came up with this exact pair of equivalent lenses for their "pro" offering. Personally I don't feel especially comfortable with this pair of ranges and I'd appreciate your input on this matter. The 24-70 offers a good wide to "slightly longer than standard" range, but, for me at least, it is wider than I usually use and I can't use it as a standard portrait lens. As a walkaround lens, it's also quite limited IMHO. I'd rather have a 35-100 personally. The 70-200 is OK as a portrait lens but has limited far reach to be used a true telephoto. Again here a 100-300mm would be much more useful, always for my taste. So I'm thinking that perhaps a future 12-60 from Olympus, together with their rumored 40-150 f/2.8 would be a more suitable selection for me. I guess the crucial parameter is this: for your type of photography, if you only had two zoom lenses, what would be the pair that forced you to make the least amount of lens changes while shooting?