DIWA Labs tests Pentax smc DA* 50-135mm f/2.8 ED IF SDM lens with Pentax K20D DSLR camera
DIWA Labs has tested the lens Pentax smc DA* 50-135mm f/2.8 ED IF SDM with a Pentax K20D DSLR camera. This telephoto zoom seems pretty interesting with the constant f/2.8 throughout the zoom range.
DIWA Labs says that the Pentax lens is produced by Tokina and it is pretty similar to the Tokina AT-X Pro DX 50-135mm f/2.8 lens
Read the tests of the Pentax smc DA* 50-135mm f/2.8 ED IF SDM lens here.
The tests done by DIWA Labs are very technical so you need to read their test guide to understand the test results.