Frustration with Canon 50mm f1.4

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garywoods

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Purchased a Canon 50mm f1.4 in November last year and initially was using this on my old 300d.

In the first couple of outings with the lens I was generally happy with the results. Images were sharp from f2 as suggested in most of the reviews and I had a huge improvement in IQ over the kit lens.

Few weeks, and not a huge amount of shooting later, and I seem to start "missing focus" on a large portion of the shots the magic somehow seemed to have disappeared. This was particular apparant at distance.

Initially suspecting my technique I persevered.

I had reasonably consistent front focus both in real world shots and on various test charts etc.

Having no MA adjust on the 300d I sent the lens into repair under warranty at just two months old. The repair centre agreed with me and carried out some electronic adjustment on the lens.

When the lens was returned I had just upgraded to a Canon 7d and again with the first weeks shooting I was pleased. I Repeated a load of focus tests on this body to my satisfaction and real world pictures were all sharp.

Few weeks later and again im now getting mushy images from it.

So I set the 7d up on a tripod, focus target on the wall parallel to the sensor at 2.5m. In live view contrast detect focus is spot on (as you'd expect).

The minute I switch to phase detect (quick mode) the lens distance indicator moves when AF is activated, i.e. sends the lens out of focus.

I'm now needing the full -20 MA adjustment with this lens to just about get focus in line with contrast detect. This was previously not the case.

Has anyone else had this apparant shift out of calibration with this lens in such a short time?.

I'm reasonably disapointed with it. I've repeated exactly same test with the kit lens and between contrast detect and phase detect the lens barrell does not move and the image is of equal sharpness with no MA so it's not a body issue, you simply get the focus confirmation beep.

I'm thinking of sending it in again but this time to Canon Ellestree rather than one of their approved suppliers?.

Be interested as to your thoughts.

Gary
 
Hi,

Yes I bought a hood with the lens after reading the reviews about AF trouble with knocks to the barrel.

Its only ever been off the lens when it was sent in for repair!.

One further piece of information i missed out from the above post is when I use EOS utility and shoot in live view through the screen, you can advance the focus back and forward with the arrows.

On my old 18-55 kit lens the adjustment for one click of the button seems very fine adjustment, whereas on the 50mm one click seems to make a huge difference, its like its very coarse in comparison.

Gary
 
so once the repair centre had carried out the electronic adjustment of the lens, did they give you a repair report to indicate what exactly the problem was and, why it may have happened in the first place?
 
That is a very good question, and one which I posed to the repairer after they sent me the invoice, which just had a note to say AF checked and adjusted.

I would have preferred more information than they just checked and adjusted it electronically but they would not provide me it.

The answer basically was that if it wasn't out they wouldnt have adjusted it.

They claim to keep no records. When asked if they could just speak to the technician who repaired it only the day before they basically couldnt be bothered.

This is why i'm thinking of sending it directly to Canon rather than an agent.

Gary
 
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garywoods said:
They claim to keep no records. When asked if they could just speak to the technician who repaired it only the day before they basically couldnt be bothered.

This is why i'm thinking of sending it directly to Canon rather than an agent.

Gary
Click to expand...

Canon will be no different in that regard, speaking from personal experience.
 
Thought i'd follow this up.

After sending to Canon Ellestree for calibration the lens now behaves properly.

One of their technicians actually rang me to talk through the problem.

Once he had worked out that I had tried lots of things before sending it in he calibrated the lens on their 7d body.

He did highlight some of the weaknesses of the focus mechanism on this lens i.e. lash in the gearing, non ring usm.

Repeating the above tests after the lens was returned to me shows that the contrast detect and phase detect now match. i.e. no movement of the barrell when switching between the two.

One thing to also point out is that the focus adjustment ring feels much more free and when clicking the advance focus button in eos utility the focus adjustment is now much finer for every click. So I don't really know what they have done but it seems to have worked.

I will now get out and do some real shooting and monitor its progress.

Gary
 
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