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Eos 24 1.4 II focus issues?

turtle

New member
I just bought this lens and a brand new 5DII and have had no issues at all with the 70mm Sigma macro (smack on focus, etc), but the 24mm is another story:

It seems to focus erratically. I can shoot five identical frames at infinity and at least half will be out of focus; some by a lot. I cannot predict when it will lock on accurately. Same prob at middle distances. Sometimes every frame is sharp. Sometimes every frame is soft even when I refocus for each one!

It focus shifts a hell of a lot up really close. Like many inches (front).

It seems not to need any micro adjustment at most distances, but if I adjust for up real close, it is out at infinity and middle distances.

It repeatedly grabs accurate focus on crisp detailed subjects at middle distances and is very sharp by f2 and very good at 1.4.... but point it at a human face and it usually misses focus. Even at 1-2m and f4 frames are usually soft. Put a beer can at the same distance.... perfect focus.

I dont get this. It can focus accurately one minute then two hours later I can do some more shooting and it consistently misses. Its as if lighting, subject colour, light levels are messing with it.

The sigma, you guessed it, smack on. Always.

I am figuring the issues is not withe the body but the lens. Its so inconsistent I dont even know the cause or even factors for sure. Optically its incredibly good, but if I cannot be remotely sure of accurate focus, whats the point?

Any thoughts? Head of this erratic focus before?
 

ReeRay

Member
A thought.

I only use the centre AF single focus point.

Maybe the drive is set at A1 Focus or A1 Servo and not One Shot.
 

turtle

New member
I found it poor on the outer focus points so switched to the central one only on single shot.... and better but still bloody awful.

I can use the Sigma 70mm with the outer ones and they are nice and accurate in decent light.

I am returning the lens. I think something is wrong with it.
 

Helena

New member
Sorry to hear about the problems! Maybe you should send it back and try another? My 24LII focus perfectly at all times and distances, so it's not a generic fault with this lens.
 

turtle

New member
I have just tried that body with my sigma 24-60 ex DG and it gets the focus consistently right at the 60mm end and consistently all over the place at the wide end, focusing (on an infinity distance) at anything from infinity to 3m.... Seems like there might be nothing wrong with the lens and something about the body that just gets everything wrong with wide angle lenses?
 

pfigen

Member
Autofocus with wide angle lenses is notoriously difficult, but you should be getting better results than you are. Part of what you may be seeing is one of the real reason people still prefer 1 series bodies. The AF is really that much better. If you're not happy with the lens, by all means, send it in to Canon with detail information and sample files demonstrating the problem. That's why you have a warranty. It's entirely possible it's a simple internal adjustment.
 

Sharokin

New member
I bought my first 24 1.4L II from J&R in New York. It was easily the most defective lens I've ever purchased!
My second copy is exceptional!
I did a test against the Zeiss ZE 21mm using a 5D MK II and found the Canon sharper at F/2.8 middle only, while the Zeiss has slightly better corners.
 

turtle

New member
Well, I have my replacement through and it is spectacular. I am seriously impressed. Focus is very accurate at all distances and while 1.4 is a touch hazy/soft, it is still very usable and much better than one might expect. Its only when you get into trying to read small text at distance and with the subject very small in the frame. It very quickly improves and before f2.8 there is not a lot more sharpness to come on centre and not that much more in the corners after f4. This lens is worlds apart from the first one which seems to focus (or not) on whim and without rhyme or reason when it didn't feel like hitting the mark. I am going to enjoy using this lens a lot... It will be a great compliment to my 85 1.2 L II and in time I am sure I will add the 35 L, but hope they introduce a Mk II version before too long with less CA at wider apertures.
 
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