Fast at f/2.8. Sharp, contrasty, good bokeh, low distortion.

VERY heavy. With a 6008i, prism it is back breaking. QC sometimes spotty. I had two bad samples before I got a good one. Difficult to use handheld, need sturdy tripod. Hard to focus accurately (very shallow DOF) with prism. Need the WL finder with its magnifier, but this causes lateral inversion. This is true for all fast teles, so it is not a weakness of this design, strictly speaking.

Excellent lens, very fast, very sharp. I had the misfortune of getting a couple of bad samples initially, but finally I got one that is just fine. This lens is a monster - weighs over 1500 grams, takes 95mm filters, Bay 104 hoods and is six inches long. If you are thinking about handholding this, forget it. You will need a sturdy tripod. With a good tripod and mirror locked up, its true perfomance potential comes out. The lens is very sharp wide open, but depth of field is so tiny that the slightest focusing error will give you soft pictures. You have to be really careful. By f/4 the lens is fine, and very little additional improvement occurs till f/11, after which there is some sharpness falloff because of diffraction. However, all this loss of sharpness is insignificant compared to the potential unsharpness you can get because of vibrations. And the 600x mirror does cause some slap, even though it is very well damped. Contrast is fine, distortion is minimal, the lens is fast. A great portrait lens.

Customer Service

Poor in the USA. International warranty is not honored, even if you purchase it from an authorized dealer abroad. Quality control is spotty. See my experiences with this lens in the MFD archives of ph