Thanks Richard.
So in terms of image quality only, are you saying that the L lens would be false economy and I should look at EF-S lenses given the camera I have?
I wouldn't say false economy necessarily, it depends. But one of the things about all L lenses is that they are designed for full frame, and you pay a lot for that, both in terms of reduced spec and cost, and you're paying for sensor coverage that you cannot use.
Compare the 17-40L f/4 and humble EF-S 18-55mm f/3.5-5.6 kit lens. For a fraction of the price you get more range and IS. Or the EF-S 15-85mm, massively more useful and just as sharp.
Compare the 16-35L f/2.8 and the superb EF-S 17-55mm f/2.8 IS - cheaper, more range, and IS. The combnined demands of an f/2.8 aperture and full frame coverage are very restricting to lens design.
The advantages of the smaller format run out very quickly after about 50-60mm, so there is no real point in making longer EF-S lenses.
The thing about upgrading to full frame in the future is a red herring IMO. For a start not many people ever do it, mainly because it costs about double, but if you do, your full frame lenses will behave completely differently so you'll have to shift around and replace your focal lengths anyway.
And then there's the cost. What you loose selling on a
good EF-S lens is a fraction of what you'll lose on the camera body, and in the overall scheme of things, not that significant anyway.
I just did exactly that - sold my entire 40D outfit on here (in just a few days). The biggest cost was that I only got £400 for my 40D - great camera, mint - and the new 5D2 cost £1500. Not too worried about a hundred quid on lenses here and there. If you buy
second hand in the first place, selling on might cost you nothing at all.
My 40D outfit was basically EF-S 10-22, EF-S 17-55 2.8, and 70-200L - very good it was too
