I guess mine would be the 100-400 L; it took most of two days to get the whole push/pull thing going right (which I'm convinced is just a dust bellows anyway) and it's heavy as hell (after back surgery). One of the pictures I love most dearly was taken with that lens on a 30D, though...
ocean7 wrote:
I'll sound like an alien but I would say 35mm f/2. That was a wonderful lens on a crop body but now that I have a 5D I can help noticing the sharpness falling apart in the corners, and that's until f/8 or something.
I absolutely love that lens on FF, I simply don't look at the corners at 100%
I would say my MP-E 65 lens, it was torture at first. I hated this thing, even put in the closest for a while. I picked it up again and actually figured out how to use it. Now it is my favorite for macro work.
The MP-E 65mm 1x - 5x f/2.8 lens. There's no AF or even manual focus in the usual sense. You basically just choose a magnification and move towards or away from the subject until it's in focus, there isn't even any focus confirmation beep/light. How sharp the focus is depends on how sharp your eyes are. Now try it with a moving subject.
Using this lens really gives me a different perspective when it comes to AF. It really teaches me how to anticipate a moving subject and not to rely too much on AF. Now FTM is a very important feature for me.
I have a love-hate relationship with my 200/1.8L. Love the bokeh, sharpness and speed. Hate to carry the darn thing anywhere - it qualifies as self-inflicted pain in my books.
I bought when our dollar was low, and shelled out $2200 for the beast. I couldnt help but feel all of my images from it were soft - told myself I was just pixel peeping too much.
Sent it in for calibration *twice*. The first time, it came back just as bad, if not worse. Fortunately, the second time they actually replaced hardware inside the lens, and it is now razor-sharp. It is by far my favourite lens.
My 50/1.4
It is a constant source of frustration/joy as well. More often than not, frustration when used nearly-wide or wide-open. The CA's and halation are very difficult to control.
It is a constant source of frustration/joy as well. More often than not, frustration when used nearly-wide or wide-open. The CA's and halation are very difficult to control.
I understand that one all too well. Canon Canada kept mindlessly focus-calibrating mine while I've been only complaining about softness f/1.4 to f/2.8. Focus was dead on all along. In the end, although the lens was apparently "within their specs", it certainly was not within my specs, so they refunded the cost of the lens in order to make me go away.
Subsequent to that I got lucky with the 50 f/1.2 .....however, let's not digress.
Mine was the 28-80 3.5-5.6 lens that came with the Elan II kit many years ago. I never figured out whether it was my skill (was a beginner) or the lens. Patience got the better of me. I sold the 28-80 3.5-5.6 lens after experiencing the 50 1.8 Mk I.
Then came the 28-105 3.5-4.5 to replace the 28-80. While the 28-105 has been okay, I have always wished for something "better" that didn't need me to re-mortgage my house.
You can pretend if you like. 
