The only thing that disappoints me about the 12-40mm is that it's not an internal zoom lens. You hardly ever see photos of it at max zoom and then I saw it one day and thought 'why?'; this is a design feature that I'd expect from a variable f stop zoom, not a constant f stop, pro, zoom. But then, maybe this is the only way to keep the size down on these lenses, something has to give. I do need to caveat this with the fact that with the 14-35mm f2, the front does move in and out slightly, but not like the 12-40mm, which reminds me of the 14-54mm f2.8-3.5.
I guess I am a bit spoiled. I suppose that's why the 4/3 lenses are so expensive compared to the likes of equivalent Canon/Nikon lenses, it must take a lot more effort and expense to build fast lenses that don't telescope.
I'm not sure which 4/3 lenses you're talking about - the only fast internal 4/3 zoom was the 35-100/2.0, and that's just what every fast 70-200-equivalent lens is these days. I'd rather have a lens that was short most of the time and telescopes, than one that has to be 50% longer to accommodate the internal zoom mechanism.
The 35-100mm and 90-250mm are fully internal zoom lenses, the 7-14mm and 14-35mm move 'in and out' (out at the wide end, then inwards and then out again at the long end) a very small amount (the 7-14mm has to be viewed inside the lens hood for the mm of movement). What I meant was that I was surprised that the 12-40mm moved out so much.
Well, it's a 3.3x constant-aperture zoom that goes from ultra-wide to moderate telephoto - something 4/3 never had. No doubt they could have made it an internal zoom at the expense of making it much bulkier and heavier - but I think most people prefer the current arrangement.
I must admit that I've never understood the desire for internal zoom lenses. Given a choice between a lens that goes from 'small' to 'big' or one that's always 'big', I'd choose the former. I've not owned a lens yet where internal dust has affected the image.
One reason I've always preferred low multiplication factor zooms ie under 3x, is because they tend to be a lot better optically across the entire zoom range. You do pay for it with a size penalty, but that's something I'm happy to live with.
Many of the 4/3 HG lenses were excellent in their own right, but there has been comment by a number of photographers etc who have suggested that the SHG lenses were designed for much higher resolution sensors than were available with 4/3s. I suspect that much of that speculation was true. Ideally, I would have preferred the 14-35mm to be wider, say12-35mm, and I believe that Olympus considered this, but that the lens would have become so large that it would have drawn adverse criticism.
Uhh... I think the size of the 14-35/2.0 already did attract a lot of criticism. That thing was bigger than my Nikon 24-70/2.8!
It'd be really nice if photozone or lenstip were to do a review of some of the SHG lenses on a modern m4/3 body so that we could reasonably compare with the 12-40/2.8 and other new high-end m4/3 lenses. I suspect the results would surprise a lot of people.
But remember, all these old 4/3 lenses were made to be tele-centric in design; whereas, the new m4/3 lenses are not