Testing has progressed, the lens has no real defects, it is like new in every way. I cannot recommend this lens enough, very even illumination, very flat field, very sharp fully open, balances fantastic on the gimbal tripod head, smooth focusing, the real question is can you use one?
Here are some tests with TELEConverters. I do not have a TC20EIII like Jose, just lowly TC14b, TC16a and TC301. It works great with the TC14B and the TC301, it autofocuses with the TC16a with a sharp image in the center that quickly deteriorates. The TC14b and TC301 need a little axial aberration correction. Jose's TC20EIII must be better but these are 'eminently usable'.I was using higher ISOs, thereby a little grain.
Here is the evidence, if you are curious about the lens look at the 100% size in flickr.
The sky was hazy due to the fires. Processing of the two moons is copy paste, therefore the color and contrast difference is the converter's. I can get similar pics of the moon with other lenses, but getting them with the 800mm and on TC-301 was easy, instead of 1 in 20 being sharp, 80% were.
Testing has progressed, the lens has no real defects, it is like new in every way. I cannot recommend this lens enough, very even illumination, very flat field, very sharp fully open, balances fantastic on the gimbal tripod head, smooth focusing, the real question is can you use one?
Here are some tests with TELEConverters. I do not have a TC20EIII like Jose, just lowly TC14b, TC16a and TC301. It works great with the TC14B and the TC301, it autofocuses with the TC16a with a sharp image in the center that quickly deteriorates. The TC14b and TC301 need a little axial aberration correction. Jose's TC20EIII must be better but these are 'eminently usable'.I was using higher ISOs, thereby a little grain.
Here is the evidence, if you are curious about the lens look at the 100% size in flickr.
