BirdForum is the net's largest birding community dedicated to wild birds and birding, and is absolutely FREE!

Register for an account to take part in lively discussions in the forum, post your pictures in the gallery and more.

Reply to thread

Message: <blockquote data-quote="Chosun Juan" data-source="post: 3760941" data-attributes="member: 92780">I must say, I am finding these new lightweight MkIII (both 600/f4 and 400/f2.8)  MTF charts a bit puzzling ........ :brains:It looks like more than just a small hit compared to the MkII's ...... so perplexed was I that I checked the 400 too, and it's showing a similar drop off in theoretical IQ like the 600.I mean these new MkIII charts look more like they belong to a Tamron than an uber dollar Canon supertelephoto ...... they are definitely not a Tamron price though!  :eek!:Even more puzzling is when you look at the new lightweight Sony 400 f2.8 G-Master (which is essentially the same lens design concept as the new MkIII's) and it has a stellar MTF chart - more like the highly regarded MkII Canon's ......Curiouser and curiouser   :cat: :cat:Chosun   :gh:</blockquote>