Thanks,Brian. Btw. the 70-200 f2.8 IS can be put on a tripod with the IS still on. Is it sensitive to the stability and switches itself off or is it designed to overcome the problems that comes with leaving it on ?
The answer to my question then, is that the 70-200 f2.8 is sharper than when you allow two stops of light on the 10-400 to compensate for the two stops of aperture difference simply on the issue of glass quality. So that's sorted that out. I would go for the f2.8 non IS . The f4 non IS - £ £414 and with IS..£719. The f2.8 non IS - £758 with IS £1178..( source..Pricebuster)
My neighbour also has the excellent 70-200 f4 IS (every photographer should have one, lol) I've used it a couple of times but I'm not very good at handheld (maybe I should practice more) and it only weighs 26.8 oz. (1.7 lbs.) I read many reviews on the 100-400 and was aware, as you've mentioned, it is soft at f5.6 and it likes light - but I needed reach, I don't photograph sports but I do like to photograph birds in flight - the Red Kites for instance,I think I'v posted a couple on here when I first came on.I took my neighbour's 70-200 but quickly realised it didn't have enough reach so I wouldn't be getting the f2.8 for reach but quality. I also love aircraft, I go to Farnborough and the one near us at Fairford only 24 miles away.
The 300mm f2.8 IS is £2874 (the f4 £874 - what a difference for 1 stop of light,such a difference I had to double check this) Here's a review of the 300 f2.8 and before I got this review up I was about to write that we have to do what we can with what we've got here in the UK but if I lived in the US or Africa with it's diversified wildlife and wonderful scenery, especially so in the US , I'd definitely be looking at a prime lens like this and then I saw that the photos in this review were taken in Africa but here I would have a job justifying it tbh for what I do.
The 300m f2.8..
http://www.the-digital-picture.com/Reviews/Canon-EF-300mm-f-2.8-L-IS-USM-Lens-Review.aspxHere's the review on the 300mm IS f4 and it looks very good indeed. I really can't justify the 300mm f2.8 IS (I see there's no non-IS with either of them) at almost £3000 though. An awesome lens,indeed. I particularly like this reviewing site.
http://photo.net/equipment/canon/300-4Here's a couple of reviews on the 100-400 which you may find interesting.
http://www.the-digital-picture.com/reviews/canon-ef-100-400mm-f-4.5-5.6-l-is-usm-lens-review.aspxhttp://www.wildaboutbritain.co.uk/reviews/showproduct.php/product/297I read several reviews when researching because reviewers (I know a tester..rather than a reviewer and he told me.. lol) get 'goodies' from the companies - not bribes of course but maybe good offers SO.. I look around and take an average.
The problem with prime, as you'll appreciate , is that it's fixed. I've often wondered about this when you want to shoot wildlife yet many bird photographers carry round the huge 600mm prime and now there's an 800mm prime f5.6 (£7700) What if it's a wader for instance , I assume it would have to be the right distance away ? This has baffled me for a while. With the zoom you just pull back or extend with the lens. I've never tried a prime so I can't answer this for myself (I do have the 28mm f2.8 for the stars but I've yet to use it but this is different to a bird that can come closer or go further away)
