[this is not a test to compare among brands … just a plain test on tc effect]

many years back before I upgrade to Canon mark2 tele lenses … I always try to avoid tele-convertor 2x … max I used is 1.4x but than still minimum use due to the quality drop is too much to worry ..

since then I upgrade to CANON ef 500/600 F4 IS2 and tc 1.4x and 2x mark3 … I have my own rule to apply the tc to get my acceptable quality picture .. and here I would share some of my capture (and I am not trying to share 1-2 case picture .. pictures sharing here are based on my common standard of shooting result) …

to make good use of the TC mark3 version .. my own rules

– enough light condition.. I can make use of any TC either 1.4 or 2x

– low light condition , try to avoid 2x tc

– very bad light condition , no TC will be use and use crop picture for final output

Update 2014 April 20 :

Orange-Breasted Trogon 橙胸咬鵑

– when the quality of air consist of moisture/mist … we can see it affect the quality (this also apply without TC)