Tamron 150-600mm f/6.3

[neuroanatomist]

I think an affordable 600mm lens with AF and VC could be a great thing for many photographers. I do worry that 600mm is a gimmick, though - that too many optical compromises were made to bring a 600mm lens down to that price point.

It seems at least possible that at 600mm, a shot from the current 100-400L will have similar or better IQ. With Sigma's affordable xxx-500mm zoom lenses, the cropped 100-400L delivers better IQ.

[Dave Throgmartin]

... I do worry that 600mm is a gimmick, though - that too many optical compromises were made to bring a 600mm lens down to that price point. It seems at least possible that at 600mm, a shot from the current 100-400L will have similar or better IQ...

If at 600mm the image quality is equivocal to the cropped 100-400 I think there's a lot of people who would be satisified although they hoped for me. If image quality is outright worse despite 2.25x as many pixels then I think the lens would be a disappointment, especially if the difference is sizable.

3rd party makers have certainly come a long way in the past few years. This may be Tamron's shot -- show us a quality 600mm for a value level cost and much more business could come their way in the future for other lenses.

$1,069 is surely inexpensive for a 600mm lens, but is still a lot of money to many people. It will need to deliver performance, at least to some extent, if they are to sell a lot of them.

Dave