Originally posted by Class A I was surprised by this
Pentax, Tamron, Sigma comparison. According to this test, the Pentax would the least preferable option.
It is a shame that many have FF issues with their first Tamron copies, but note that the Pentax 16-50 also had a bad history regarding decentering. Not sure to what extent this has been ironed out.
That's a brilliant test for side to side comparisons ! I can't understand the text but from the shots this is what I got (although this could just be sample variation too) :
Sharpest at 16/17/18mm @ F2.8 : 1. Sigma 2. Tamron 3. Pentax
Warmest Colours at 16/17/18mm : 1. Pentax 2. Sigma 3. Tamron
Sharpest at 16/17/18mm @ F8 : 1. Sigma 2. Tamron 3. Pentax (noticeably darker too).
Warmest Colours at 16/17/18mm : 1. Sigma 2. Pentax 3. Tamron
Sharpest at 30mm @ F2.8 : 1. Sigma 2. Pentax 3. Tamron
Warmest Colours at 30mm : 1. Sigma 2. Tamron 3. Pentax
Sharpest at 30mm @ F8 : 1. Sigma 2. Tamron 3. Pentax
Warmest Colours at 30mm : 1. Pentax 2. Sigma 3. Tamron
By 50mm Pentax & Tamron seem to have taken over as #1 in the sharpness and colour warmth.
In PF Tamron is a clear winner, followed by Sigma and then Pentax.
Ghosting & flare : 1. Sigma 2. Tamron 3. Pentax
Bokeh : the Sigma seems smoother and isolates better (@2.8) with nothing much between the Pentax & Tamron.
Of course this is just one test I we can't vouch for the conditions / accuracy but it's interesting to see real life side-by-side comparisons nevertheless. One thing is clear, these lenses are so closely matched in IQ that I couldn't go wrong with any of them.
Thanks for posting that Class A.
If anyone can comment on the test or disagrees with my observations - please come forward and say why, I'd love to hear other people's opinions.