Hello again Everyone
Paul (the OP!) here…
I really appreciate the input on this thread, there have been a number of really useful contributions (just as I hoped for). Thanks CR Guy for promoting this thread on the front page of CR!
The aspects discussed about potential systemic problem of certain testing techniques with UUWA (ultra ULTRA wide angle) lenses, and shorter focussing distances I can understand the logic of. So that this impacts both distortion and corner sharpness (particularly for a zoom) – yes, may be one contributing factor why those respective figures are not ‘great’ in Photozone’s tests (and potentially other reviews / tests out there… or soon to be released). But it may not be nearly as much an issue in the real world (where most photos taken at further focussing distances).
The analysis / thoughts / breakdown about different lenses I think is very important. For example- each lens is ‘fit for purpose’ – and targets a different user, which also helps us to realise we should not place too much emphasis on any comparison between Canon’s 11-24mm L with any other lens (either the Canon 16-35mm f/4, the Canon 16-35mm f/2.8, the Tamron 15-30mm f/2.8, or the Nikon 14-24mm f/2.8). I do think size/weight, functionality (e.g. filters and/or IS) and aperture speed definitely define each of these lenses as different.
For the record, I really dislike fisheye lenses (or ‘effect’) – that’s why I am super excited about the Canon 11-24mm L – but really have hardly much interest in the Canon 8-15mm f/4 L fisheye!
I have found it great to read some more ‘real user’ reports here on CR (there were a few on other places, e.g. Fred Miranda, DPReview, B&H, etc) – and this is very encouraging that overall ‘real world users’ think the 11-24mm L is a great lens, even though (for various reasons – the 11-24mm Photozone report might ‘highlight’ certain hurdles – at least, in certain situations). Very interesting that most users say it is very sharp (some even specifically say ‘corner to corner’) and that distortions well controlled given the extreme 11mm possibility, and chroma not really a huge problem. (Naturally, most people who spend about USD $3k won’t want to be disappointed with their lens… initial indications are that most are v happy with it).
I have a lot of time and respect for how Klaus at Photozone does his lens tests. He is thorough, clear and I like that his results are so easily comparable (within the 1 ‘camera / system’). I look forward to more ‘benchmark’ tests / pro reviews too – from others, e.g. SLRgear, Lensrentals, DxO, etc
My own situation is that I own the Sigma 8-16mm, which is a great lens – in fact – I feel it, in some ways heralded in the UUWA zooms. (Previously I owned the Sigma 10-20mm, and I have used the Canon 10-22mm). The Sigma 8-16mm on my 7D is equivalent to 12.8 – 25.6mm (in 35mm / FF format). (Nikon owners of the Sigma 8-16mm would get 12mm at FF equivalent). The difference between 8mm and 10mm (on APS-C) really made a huge difference for me. But more importantly – the sharpness edge to edge and low CA really made this lens be a real winner for me, as I love UUWA photos – mainly of landscapes or interesting perspectives of ‘everyday things / scenes’ and rather occasionally of architecture / buildings too! So I really don't need f/2.8 in an UWA/UUWA.
If I ever move to FF (at this stage I don’t plan to) – the 11-24mm L would probably be too much for me (in terms of what I would like for size / weight and price). That’s another reason I love the 7D / Sigma 8-16mm combination – a relatively small package still delivering great quality down to 12.8mm. I think it’s great that Canon has now made two UWA lenses with IS – the EF-M 11-22mm IS STM (for EOM cameras) – and the 16-35mm f/4 L. IS would probably realistically be the only thing that might make me choose another UWA/UUWA over my current Sigma 8-16mm… i.e. if it had IS. (Of course, should Canon ever incorporate IBIS, then that would be a great benefit too… but I doubt Canon is going down this path – at least not for EOS DSLRs at this stage!
So… I look forward to receiving / reading some more posts on this thread about the amazing Canon 11-24mm L lens. Again, well done Canon – and thanks to all who have contributed so far.
Paul