If you "noticed" I was referring to the bad bokeh mentioned before. It can be controlled in a lot of situations. But now that you brought up the other type, it is not that hard to use either. I have or have had at least 6 or 7, both the 400mm version and the 500mm, of them. I have one currently. Depends on your back ground. If you were shooting during that era when all lens' were virtually 'preset' manual focus lenses, it's not that difficult. The current crappy screens are the bad thing.
The example of the bluebird house was a Nikkor 500mm cat lens and it has a tripod foot. I have the Canon version 500mm cat also but I couldn't find a recent shot easily do forgive the brand-N substitution. Are you going to want to use a cat for cityscape night light shots? Probably not but some night lights are shot millions of time each night with a cat lens. Think about it !
EB
EOS 1D, EOS 1D MK IIn, EOS 1D MK III, EOS 1Ds MK III, EOS 1D MK IV and EOS 1DX and many lenses.
