<p>We evaluated a new Tamron 150-600 G2 and Canon 100-400. As an initial test, we made shots on a star pattern on 15 meter distance. Unfortunately, the Tamron had poor performance along one diagonal axis, 135 deg. Along the 45 deg. axis the sharpness was good and in parity with the Canon 100-400. We tried various apertures and both 400 and 600 mm, but the results very always the same; heavy color misalignment along one diagonal axis. All photos were taken with the same camera EOS7D mk2 mounted on tripod. Live view focusing was used to avoid possible focus offsets with the phase detection AF in these tests.<br>
Below are a small crop 512x512 from the middle of the image:<br>
Please zoom 300-400% and the color misalignment along one diagonal is obvious. It is worth notice that the misalignment is not possible to correct with the normal chromatic aberration setting in PS Camera Raw. In fact, the Debayer algorithm is having trouble near the center of the star.<br>
Tamron:<br>
<a href="https://farm1.staticflickr.com/421/32051995375_ed51f9c50d_o_d.jpg">https://farm1.staticflickr.com/421/32051995375_ed51f9c50d_o_d.jpg</a><br>
Canon:<br>
<a href="https://farm1.staticflickr.com/284/32051995465_417497c851_o_d.jpg">https://farm1.staticflickr.com/284/32051995465_417497c851_o_d.jpg</a><br>
We expect (and hope) is is something wrong with this lens sample and will test another one when available. However if that 2:nd sample show very different performance, the need for truly testing of each lens before buying is obvious.</p>
<ol>
<li>Has anyone seen anything similar on the Tamron 150-600 G2?</li>
<li>Should you expect large performance variations on Tamron lenses?</li>
</ol>
<p>Please avoid unnecessary comments such us “You get what to pay for” or “Do not use test patterns do shots on real pictures”.<br>
The bottom line is if the lens would perform as good in 135 deg. as it does along the 45 deg. axis then we can take the next step to do testing of all other aspects of the lens.</p>
