I just bought a 24L after viewing the results with the 85L at 1.2.
The question is if this 24L is so "hard" to use at 1.4 as the 85L is at 1.2 becouse I am getting differnt results in sharpness specially when focussing far.
While I don't actually own the 24L, I doubt it has such a steep learning curve as the 85L, since at 24mm you have much more DOF than at 85mm.
Besides, the 24L being a wide angle lens, most of the time you shoot from a greater distance to your subject, thus increasing DOF.
The 85L's learning curve comes mainly from the minimal DOF, where focus accuracy is indeed critical.
With a 24mm lens, and a slightly slower on top of that, it should be easier.
I have both lenses and have found that the focus is critical on either at maximum aperture. I have also found that I get more accurate results focusing manually than relying on the single-point AF on both of my 1DsMkII's.
A wide angle lens will yield a greater range of "acceptable" focus than a telephoto, but there is still only one plane of exact focus on either lens. If you're off at 1.4, you'll definitely notice it on either lens.
The 24L is really hard to focus for different reasons than the 85L (I have both, on FF). The magnification on the 24L is so low that the AF of the camera (in my case 1Ds3) has a really hard time to decide what's in focus and what's not, esp. in moments when you need it most: low light, wide open and thus shallow DOF.
In fact, the 24L is the only lens with which I didn't achieve better AF accuracy when switching from the 1Ds2 to 1Ds3. All others have shown sometimes remarkable improvements (esp. the 85L/II). Still, the 24L would be among my top favorite lenses (24L, 85L, 28-300L an I'd survive )
Yeah I also have trouble getting accurate focus on objects farther away as in your picture; I assume due to the reasons stated above. It hasnt really been an issue as my subjects are normally much larger in the frame and easier to focus on.
I think I will try another one or two copies at my dealerīs as the present one delivers very different results in terms of sharpness even when really filling the AF point frame.
Depth of focus is greater with WA lenses but the adjustment between the lens and body is critical because the. projected, image's depth of focus on the sensor is much less.
I own the 24L and also found there was a learning process, the depth of field at f1.4 is far smaller than I expected. The problem was caused by my expectations, nothing to do with the great quality of the lens.
I had to do quite a bit of practicing before using the lens for real at f1.4. If you are photographing static objects and can use a tripod, then I thoroughly recommend focussing the 24mm with Live View set to a large magnification. When you do this you can really see the image "snap" into focus, it brings it home how accurately this lens needs to be focussed.
The 24mm L is now one of my very favourite camera lenses, it delivers unique results, but it has its own "character" and needs some acquaintanceship before becoming your friend!
Jamie,
I just think your target is too small and you are too far away. The AF of you a camera is looking for areas on contrast within your target area. If your target is too small or you do not have enough contrast, your focus will suffer. It the above photo you have both instances occuring.
This is why most of the ultra wide angle zooms allow you to parafocus the lens. Zoom in to focus on your subject and zoom out to shoot. There is a big difference when you do this with the 17-40 or 16-35. Unfortuatly you cannot do this with a prime. That is just a limitation of the lens.
I only own a 85/1.8 and a Sigma 30/1.4 but those large appertures require much training.
Problem with the wider angel really is that you cannot point the camera so precisely at the point you want to focus at so the chance of missing it is much higher.
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