« on: October 27, 2014, 05:13:22 PM »
There are several comments here about the Tamron being soft at 600mm and slow from individuals who clearly don't have any first-hand experience of the lens and just rely on mythical hearsay or lens test from TDP, which actually shows it sharp at the centre.
I regularly use the Tamron 150-600, have used extensively the 100-400 L and have the 300/2.8 II.
The Tamron is not soft at 600mm, and it is reasonably fast at AF at 600mm. My first hand experience fits in well with the extensive reviews on ePhotozine and Lenstip. Here is the MTF analysis from ePhotozine, which has measured the values at 600mm to be on the edge of excellent at f/8, and the Lenstip's of the 150-600mm and the 100-400mm, which shows that the Tamron at600mm and f/8 to be similar to that of the 100-400 at 400.
Don't knock cameras or lenses based on hearsay, second-hand and inaccurate information.
No one is saying it's soft at 600mm and f/8, just at 600mm and f/6.3.
The sample images in the links above from fredmiranda.com might indicate otherwise. Isn't it true with most telephoto lenses that wide open and max focal link sacrifices some sharpness?
It really depends on price of the upcoming 100-400mm, and one's willingness to forego Canon L for similar performance across the same focal length. Tamron looks to be a strong contender.
No, it doesn't have to be true that it softens up at the long end. Many do, but the better ones don't. For a telephoto where resolving power is its while reason to exist, this is a major problem for people that lime to get the most from their equipment.
You made a blanket statement it was soft at 600mm, and you didn't qualify it with an f number. The current 100-400 is at its weakest at 400mm. Here is a selection of bird photos that some of us have taken with the lens at 600mm. Soft are they?
This I what I said:
I've seen plenty of full-sized shots at 600mm to know that it is soft at 600mm wide-open, even on full-frame.
I'm not a sharpness nut, except on telephoto lenses, where it's common to crop like crazy. When I can properly frame, I find my 17-40L and 24-105L to be quite excellent. But on telephoto, it's not uncommon for me to crop 2x into a shot that was shot with a 2xTC on a 1.6-crop camera. That's only 15% of the size of the image circle, enlarged to a full-frame. That requires critical resolving power.Have a look. This is the Tamron against itself (400mm versus 600mm). There's a substantial difference.
The TDP test has the lens at different distances so that the chart completely fills the frame. That is a useless comparison for comparing the resolution of a lens for a subject at a fixed distance away - the target is 50% further away at 600 vs 400mm in the TDP tests. I have posted images of the iso chart taken at the same distance away using 400, 500 and 600 mm. The Tamron at 600mm clearly outresolves itself at 400mm.