Bhargava,

I have never experienced image degradation when the 2x converter is attached to the 400mm f2.8 L IS lens. If the image is soft, then it can only be due to user error rather than the fault of the equipment. One can do testing of static subjects, but in field, it is not noticeable.

Having said that, I have to check the original image as I had processed it when I was in bandhavgarh. My images are processed with default sharpening. However, recently I saw that after the lightroom upgrade the default has changed to a soft setting.

When the tiger got up, I just aimed and fired and got about 2 frames. Didn't get time to bump up the ISO. The shutter speed was 1/200. I would have been comfortable at around 1/500 levels.

This scene interested me, as the tail, elephants leg and the tree nicely framed the subject.

Ashok,
Keep on learning here. I will organise a class for you later to bring you up to speed.

Cheers,
Sabyasachi