135/2 считается вторым по качеству портретником у Кэнона (после 85 1.2). А с покупкой телеконвертера 1.4 он превращается в 190 2.8.
Вот тут интересное сравнение 135 2.0, 100 2.0 и 85 1.8.
http://wlcastleman.com/equip/reviews..._135/index.htm
и вывод - Canon EF 135 mm f/2 L
This lens costs 2.3 times as much ($819 USD) as the EF 85 f/1.8. I consider it to be worth every penny I paid for it. It is an incredibly sharp in the f/2 to f/4 range and produces wonderfully diffuse, out-of-focus backgrounds. It is great for portrait and performance photography. It is a wonderful tool for candid portraits at events. This is one of Canon's top-performing lenses.