50mm 1.2L

[KeeFy]

I picked up a 50 1.2L yesteday and am amazed with the DOF. I did some research and don't know if anyone faces the problems i have.

AF: Sometimes it back focuses.. some times it front focuses. I don't know what to expect out of it! I tried micro adjustment but still gives the same issue. It's definitely not due to the focus shift as the subject is more than 5 feet away and i'm shooting wide open.

IQ: It seems the images are a little "foggy". VS my 50 1.8 at f11. The 50 1.2L is softer. At 1.8 vs 1.8 it's a little sharper but still with a little bit what seems to be fog/halo.

[fabian628]

samples? not sure If I understand what you mean by 'foggy'?

When you tested the sharpness were you relying on the camera's AF?

[JM Tran]

its a very well known issue with the lens - as many consider it a hard lens to use with its focusing niggles

I have always preferred the 35L over the 50L anyway, not one of my favourite L lenses in terms of consistency and IQ

[pmack]

can you confirm that you are experiencing problems with repeatability of focussing on the same distance, or focussing at different distances.
as they are potentially two or more different issues (or a combination of)

point in case, my 50 1.4 works well for short distances (2.5 meters) when micro adjusted to +3
If i want to shoot distances of about 10 meters, i need to change the micro adjust +15.
obviously i am not happy with that so i put it up on ebay :th3:
hopefully i have more luck with my next copy

[camerasnoop]

I have a 50L, and no, it's not an easy lens to use at times. In fact I don't use it much any more, except when I'm deliberately going for a miniscule dof, or when I need f1.2 at ISO3200 to get anything at all. I haven't really sat down and worked out exactly when I have problems, but I can say I have noticed that on the 5D, it will focus on objects right on the edges of the frame that I don't even see in the viewfinder, but which show on the recorded image. These are well away from the 5D's nine focus points. I don't know why it does that, but it does. It even seems to do this when I am shooting with only the centre AF point selected. How the hell that works, I have no idea. It's not a front or back focus issue because whatever it seems to focus on, that object is sharp. If I could find some that I haven't deleted, I'd post some.

Still, when the images come off as planned, the images are sensational. That's why I still have it.

[kiwi]

Id say its your lack of experience more than anything, 1.4 is not for the fainthearted, let alone 1.2 !!

[pmack]

Id say its your lack of experience more than anything, 1.4 is not for the fainthearted, let alone 1.2 !!
people on here seem to love to jump to the conclusion that people posting here are the ones at fault. Yes that is often the case, but to jump to that conclusion is insulting.

[kiwi]

i can tell you then that I often struggle with 1.4 nailing focus, so I'm at fault

and i think that's the case most of the time

Maybe it's lens

[jjphoto]

The reality of using very fast lenses, ie 180-200/2, 80-85/1.2-1.4, 35-50/1.4-1.2, is that you really do need to know what you are doing and preferably focusing manually AND on a camera that is capable of showing you where the lens is actually focused. It's understandable that people do have trouble focusing such lenses because there's a bit more knowledge and technique needed to do it consistently well. Once you add AF to the equation then you have lost a certain amount of control and accuracy, because you are letting the camera do the work for you and what if it isn't doing it right?

JJ

[jjphoto]

i can tell you then that I often struggle with 1.4 nailing focus, so I'm at fault

and i think that's the case most of the time

Maybe it's lens

The sharper the lens (wide open) the easier it is to focus accurately. If the wide open image is a bit soft then it's much harder to judge perfect focus.

JJ

[TOM]

it is always going to be a challenge accurately focusing a lens that fast with a dslr. also, do you focus and the recompose, or do you move the focus point to the point of focus? This could be the issue, regardless of whether your subject is moving.

[I @ M]

KeeFy, to satisfy yourself that the lens and camera are working as they should I think that a bit of tripod mounted testing is in order using both auto and manual focus methods.
Compare the same shot taken focussed both ways and see if there are any differences between the two methods and then begin to analyse where the focus is occuring if it doesn't appear to be happening where you or the camera choose to set it.



people on here seem to love to jump to the conclusion that people posting here are the ones at fault. Yes that is often the case, but to jump to that conclusion is insulting.

pmack, I don't see anything insulting about any comments so far and in reality comments and advice from posters in this thread echo a consistent statement and that is that fast aperture lenses are hard to use accurately and consistently wide open.
I will also add the same comment about probable user error because I have a F/1.4 lens that delivers brilliantly sharp images at 1.4 ---- but ---- only when I get it right.

[pmack]

pmack, I don't see anything insulting about any comments so far and in reality comments and advice from posters in this thread echo a consistent statement and that is that fast aperture lenses are hard to use accurately and consistently wide open.
I will also add the same comment about probable user error because I have a F/1.4 lens that delivers brilliantly sharp images at 1.4 ---- but ---- only when I get it right.
i'm probably bringing in bad blood from a topic or two that i made here some time back complaining about what I believed to be problems with my own camera or lens. I spent the whole thread responding to people presuming I had no idea how to operate the camera or read a manual, consequentially it turned into a train wreck and i think it was even locked...
anyways what i meant to say was that to say that the OP's problem is due to their lack of experience in such a matter of fact way, without knowing how experienced they are, is not a very usefull comment, and can come across as (unintentionally) insulting in my view. offering that suggestion as a possibility on the other hand is better way to do it. i'm sure the OP doesn't mind at all and it's just me being over sensitive though ;)

in order to get some usefull advice for the OP, Keefy, can you put the camera on a tripod, set the center autofocus point, take a photo of something like a wall 2.5 meters away (preferably with some things around that you can use to help judge if things in front or past the wall are better focussed...). then manually defocus to infinity, autofocus and take another shot, do this a couple times. Then take a "control" shot by focussing using live view. from my interpretation of your post, the autofocus results of this test will give shots of varying results, some in focus, some front focused, some back focused. so it seems you're explaining random behaviour. If the results are consistant, then try it again at a different distance, such as 10 meters. If the results are worse at the different distance (or better), i suggest your lens has the same issue (or behaviour) as my 50mm f/1.4. I told canon about this behaviour, and they told me it sounds like it needed to be sent in for calibration.

If results from those two tests are consistant and you're happy with them, then yes you probably need to work on your focusing technique and camera settings

[fabian628]

as other have mentioned, try to break down each variable and test it in a controlled way.
my 35L is sometimes inconsistant with focus, occationally missing completely. I am not sure there is anything that can be done in this situation and may have something to do with the subject, distance and lighting conditions.
I do not have firm source on this but I did read somewhere the optimal aperture for the AF sensor is f/2.8-f/4 when light is not limited.

[kiwi]

Paul, I did take into account the op's relative lack of history and also the fact he'd had the lens only fo 24 hours.

[andylo]

I have recently got myself the 50L. And it is a very, very difficult lens to get a tad sharp result when it's at its widest Aperture.

(In the case of f/1.2) I often find that I need a tripod + really fast shutter speed + manual focus to get the best result. (And hopefully the subject is not moving neither)

On the internet there is (consistently) a piece of comment saying it has back focus problem when focusing in close distance, I do find it is the case, hence manual focus is required.

[KeeFy]

Wow. Thanks for all the replies.

I've used it some more and noticed that at over 10m. it will front focus if i leave the mico AF at 0. If not it's bang on before 5m. AI servo on the 7D works a treat VS one shot mode. Probably due to what a few of you guys mentioned, body movement. I don't intend to take too subjects over 10m so it's fine for what it is.

I compose and then use my joystick to get a focus point and with spot/area focusing. A good habit that i've aquired over the 2 years as i know the focus and recompose causes lots of problems with fast lenses due to the thin DOF. I have my AF-on button on my 7D as AF-off. I have gotten accustomed to manual focus (i use a rangefinder, AE-1 etc with decent success) and do use it to turn off AF and manual focus on the fly.

As for the halo. I realised it's due to LoCA. So again it's fine. :)

I did try the tripod test before posting, but only at 45 Degrees to a piece of paper with text to test for front or rear focus. I didn't try the tripod mounted at a fixed distance and defocusing to infinity. I shall give a shot with that today. I suspect the results will be that the focus is accurate.

I'm absolutely loving this lens and will be running around with it for the next couple to few weeks to get used to it. It is really a harder lens to get right when it's wide open.

I have had the opportunity to use a Sigma 1.4 with relative ease. I wouldn't have throught the 1.2L was so much harder.

[pmack]

Paul, I did take into account the op's relative lack of history and also the fact he'd had the lens only fo 24 hours.
am i missing something, where'd you get access to my name?

Keefy, looking forward to your results. I don't think a 1.2 should be much harder to use than a 1.4 if you're taking shots at the same aperture, and there does seem to be a common theme here of people having focusing issues with that lens

and what's LoCA? low chromatic aberration?

[kiwi]

Dunno, I thought it was paul, I'm not sure why, is it ?

Agree that there could be a few problems here.

[pmack]

Dunno, I thought it was paul, I'm not sure why, is it ?

it's the name i signed up with, but i never use my name in posts. Though mods like I @ M no doubt can see our names..

[kiwi]

There's another member paulmac so I probably just get muddled

I'm not a mod (I'm not an Australian citizen)

[pmack]

just when i thought i uncovered a conspiracy :P