Originally posted by stihlmania Sorry I did not get the exif data set correctly, its a SMC A * 400 f2.8 with the Pentax AF 1.7 adaptor. Technically a 680mm but I set the lens length on camera to 700 for the shake reduction [I have not really tested the SR at this lens length to see if it helps at the shutter speed I was using]. I used this set up today with the cardinals and this fox...
Oh, you set the EXIF data correctly, I just couldn't figure it out!
In my experience using the AFA 1.7x with a 300/2.8, I needed to stop down a bit to get decent results, not just for sharpness and contrast but also because depth of field is so thin, particularly when backyard birding.