Originally posted by pinholecam There are not many if any recent Tamron lens that is worth worrying over.
Those that are good enough to consider are already in K-mount :
ie.
90/2.8 Macro
17-50/2.8
70-200/2.8
28-75/2.8
Sigma is a bit of another story. Their new lenses seem pretty good.
But I stay away from them due to 3 incidents of poor quality.
Somewhat true for now, but what about the future as lenses are replaced? It doesn't bode well that the lenses specifically designed for APS-C sized sensors (which all current K-mount Pentax cameras have) are not being introduced with a K-mount. Edit: Those are the lenses labeled "Di II."
Tamron lenses that are interesting to some degree but not available in K-mount:
Tamron SP 60mm F/2 Di II LD Macro 1:1
Tamron SP 200-500mm F/5-6.3 Di LD [IF]
Tamron SP 180mm F/3.5 Di LD [IF] Macro 1:1
Worrying because they don't exist, but not as interesting (to me):
Tamron 55-200mm F/4-5.6 Di II LD Macro (Close Focus would be a better label)
Tamron 18-270mm F/3.5-6.3 Di II VC PZD (If it were only this I might think that it was just because it was a Vibration Control model, although it is also the first lens with the new Piezo Drive silent focus motor)
Of course Tamron lenses are often made available in Pentax mount later than Canon or Nikon mounts, but some of these lenses have existed for a long time and are still not available as a Pentax mount. When was the last time Tamron made a lens newly available for Pentax cameras?