They were hand held, but the light was very good, so if I remember correctly I used a fairly high shutter speed. In addition, the subjects were not moving very quickly, if at all. The rhino, lion and owl were certainly not going anywhere fast. The peacock was gracefully walking around, but getting that shot took a few tries.Antonio, are those hand held?
I have a 135 in M42 mount and tried it on my Nex3 once. Composing with it was so wobbly that I haven't used it since:-(
But your results are lovely, will have to try and brace it on something.
I think what helps with this particular 135mm is that it really is very light and small, and therefore relatively easy to hand hold, even if the image does jump around a bit in the viewfinder. I think it's a four element lens, and the filter size is 52mm, so that gives you an idea of its size. It's actually smaller than any DSLR normal kit zoom lens that I have tried.