If you use AF-C the lens may give some AF problems, I think. I always use AF-S, centre point only. My copy does not misfocus. I use a Leica SL2-S and the camera automatically chooses a higher shutter speed when zoomed in.
no, I almost only use af-s, and only have misfocussed photo's at the long (dark) end, especially if the subject is darker or low-contrast. I think that s5ii gives focus confirmation, while the af actually did not achieve proper focus. It's not the lens it self. And it is only more common with far away subjects. In a zoo or whatever it works fine also with af-c, but a distant building or mountain (like >1km), especially with some haze/low contrast is very difficult for this lens/af combo. Used the lens for about 1/3 of my pictures in total in my last vacation, so fair amount.
so, don't take it as a blame on the lens, it's an observation I made and it happens only under specific set of circumstances. Luckily I found it out on the first outing last vacation and by being careful in those situations helped me out just fine. Going "back" to my 24-105 has more to do with that I don't seem to use it that much >100 anyway. And bringing less stuff with me removes choice anxiety on vacation. I like the rendering of the 24-105 over the 24-60 outdoors. 24-60 might be too sharp for me giving a more digital picture look. But not always, depends on stuff like angle and intensity of light, and how harsh the contrast is. Indoors I like the 24-60 more. Every lens is a set of compromises with a lot of variables:
- sharpness
- rendering (warm/cool/microcontrast)
- vignetting
- weight
- af / af speed.
- min/max aperture
- price
- etc.
And everybody prefer different things, so what I like or observe can be totally different except for things you can actually measure like contrast and sharpness. For every lens I own I can name multiple things I like and dislike. 24-105 flares easily, and lowers contrast when shooting into the light source (but if you know how it does it, it can be used as an advantage as well) and it's overweight. The biggest strong points and makes me keep the 28-200 for now is its versatility and compactness/weight but also it's rendering. Ideal for long/heavy hikes.
Why I would ditch the 28-200 for a 50-200 would be that I'd then take the 24-105 as an only lens on hikes, or 16-35 + 50-200 as a two lens combo (or 24-60 + 50-200). Makes more sense to me. A 20-60 + 50-200 could also be a very nice vacation combo.
On topic, a lightweight small 200/4 would be nice as well instead of 50-200/4-5.6..., same size and weight as the 100/2.8. I think it can be done. An aperture of 3.5 If they can squeeze it in the same size/weight constraints.