Camera Guy wrote:
Hey Bob, what do you think of your EF 70-200mm f/4L IS USM? And what's your opinion on multiplier's?
I'm delighted with it though I don't give it as much use as its quality or price deserves. The timing of the purchase was accelerated slightly by that £80 Canon cash back offer.
As for multipliers (or extenders in Canonese) there has been quite a lot of discussion about these in other threads. Canon are quite restrictive about which lenses they say are compatible with their extenders (and the 2x extender's list is even more restrictive than the 1.4x). Extenders will show up the defects in any lens very nicely but as the EF 70-200mmL IS USM is as sharp or sharper than many primes (though at f/4 it wouldn't be as fast) I have no concerns about using it with a 1.4x extender should I purchase one.
If I had a need for a really long telephoto then the most affordable choice in Canon's pantheon would be the EF 300mm f/4L IS USM. Affordable maybe only in relation to other long Canon glass, of course, but it is readily available for under £900 in the UK (€1350/$1800), and while it only has first generation IS the PhotoZone test results
show it to be both optically and mechanically excellent. That report also gives the resolution figures when this lens is used with the 1.4x extender giving a 420mm telephoto and this combination still achieves very respectable resolution figures. In 35mm full-frame terms this is equivalent to a 672mm f/5.6 telephoto (long enough for the birders I imagine) for under £1100. Definitely a tick in the cropped sensor column in my opinion.