[dave9t5]

I wait and wait to see if Photozone do some tests on lenses by Sigma, Samyang, Tamron and other manufactors for alpha mount lenses. But it seems that i´m waiting in vain for this. So whats the reason for this ?

 

The reason is that you can simply check the Sigma, Tamron, Samyang results in the Nikon or Canon sections.  The lenses and their properties are the same, just different mounts.  The results will be very similar (*) whether on Nikon, Canon, Alpha, Pentax, etc...if it's good on one, then it will be good on another, etc.  There is no point in re-testing them on every mount...that would just take a valuable opportunity to test more interesting native lenses on the less popular mounts such as Alpha and Pentax.  

 

*These comments apply to the mirror-box-mount full-frame and APS-C results.  The basic mount geometry and pixel pitch is really similar between all the systems.  With the smaller sensors (i.e. Nikon 1) or very short flange distances (NEX, Leica) then some other issues come up.