Re: Does Tamron pay DXO Mark?
Cameralabs did extensive testing of the G2 Tamron (A022), and found the results slightly better than the original (A011). They were not "terrible" in any sense of the word. Soft in the corners @ 600mm full frame, as were both Sigmas and the older Tamron.
Their final verdict was: "An improved image quality combined with a good image stabilization, improved sealing, shorter minimum focus distance, and an acceptable size and weight makes Tamron's new 4x super-telephoto a compelling package. It's a pity that Tamron didn't position it as the successor to their A011 model at the same price-point. But it certainly earns a Recommended rating."
They did extensive testing on optical quality and posted the target images at multiple focal lengths, f-stops, distance from center and for 5 models total (old & new Tamron, Sigma Sport and Contemporary and the Nikon 200-500). Useful because it demonstrates the limitations of long tele-zooms. None are as good as proper primes, equally none are as bad as wide to tele all in one zooms, which top out at 300mm anyway. If you're getting "terrible" images with any of the 5 long teles, it's likely failure in technique. None of the lenses are junk.
That being said, i agree with wondering why dxo's tests fare differently than others. Hence my question if multiple samples were tested. Roger Cicala tests ten samples of every lens. I'd think a minimum of three would identify an anomaly vs. systemic problem with lenses.
If this lens follows suit with other Tamron refreshes, i.e. the SP 90mm macro, similar optical performance with improved sealing, vibration reduction and the ability to use the Tap-in dock might be reasonably expected. I'd like to know if Tamron is relying on the Tap-in dock vs. factory tweaking as would be required for older lenses. Maybe dxo can run a 2nd sample of this lens pre and post Tap-in focus adjustment? (Preferably on the D810)