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Does / did your 50L backfocus and what happened?
Bought one, love it, no problems		19	4%
Bought it, no problems, but not that impressed		6	1%
Mine had the focus problem, I returned / sold it		15	3%
Mine had the focus problem, but it was possible to sort it		6	1%
I would have bought one but am waiting because of the focus problem		41	9%
Just show results		391	82%
Total Votes		478	100%

Archive 2007 · Where are we with the 50L?

ansye
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p.2 #1 · Where are we with the 50L?

I got my 50L and I am still looking for the issue people are talking about. I haven't encounter any issues taking pictures close and far and with abundant light as well as dark kitchen etc. How do I make sure that my copy is indeed not suffer from this issue, or otherwise?

thank you
ansye

Jun 27, 2007 at 08:03 PM

Roy Pertchik
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p.2 #2 · Where are we with the 50L?

I e-mailed a Canon insider and learned that there is no new word from Canon since a month ago when they said to expect a public announcement. He recommended:

.... contact our Customer Support Center directly if you wish to pursue the matter:

* E-Mail: Send an email to carecenter@cits.canon.com.

* Telephone: Call Canon’s Customer Support Center toll-free at 1-800-828-4040. Kindly provide the service representative with your contact information, your EF 50mm f/1.2L USM serial number, and details about the focusing issues you are experiencing.

Sounds like it would be productive to remind Canon that there are Canon users who would like to hear a statement.

Jun 27, 2007 at 11:06 PM

cactusclay
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p.2 #3 · Where are we with the 50L?

ansye wrote:
I got my 50L and I am still looking for the issue people are talking about. I haven't encounter any issues taking pictures close and far and with abundant light as well as dark kitchen etc. How do I make sure that my copy is indeed not suffer from this issue, or otherwise?

thank you
ansye
Try taking a head shot of someone at about three and a half feet away. Focus on their eyes or one eye at F4. If the nose looks shaper than the eye, you may have a problem, or shoot the eye at 1.2 to 2.0 and see if that is sharper than the F4 shot is. Or, you can shoot a ruler or one of the test charts

Jun 28, 2007 at 12:09 AM

tmr4
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p.2 #4 · Where are we with the 50L?

cactusclay wrote:
ansye wrote:
I got my 50L and I am still looking for the issue people are talking about. I haven't encounter any issues taking pictures close and far and with abundant light as well as dark kitchen etc. How do I make sure that my copy is indeed not suffer from this issue, or otherwise?

thank you
ansye
Try taking a head shot of someone at about three and a half feet away. Focus on their eyes or one eye at F4. If the nose looks shaper than the eye, you may have a problem, or shoot the eye at 1.2 to 2.0 and see if that is sharper than the F4 shot is. Or, you can shoot a ruler or one of the test charts

The second test, see if the wide open shot is sharper than one stopped down, is the test. The first would be ok for a face shot at an angle.

Here is a crop of the problem I posted earlier in the thread:

http://www.fredmiranda.com/forum/topic/547792/2#4761537

and a link to my tests:

http://www.pbase.com/tmr4/distance_test

Jun 29, 2007 at 04:34 AM

jm42
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p.2 #5 · Where are we with the 50L?

I have seen posts suggesting that there is no focusing problem with the XTi. However, they did not elaborate. And if the problem is focus shift I cannot really see how the XTi could be more successful.
Still, this is high-tech world and almost anything is possible, and clearing the 50L for use with my XTi would be wonderful, so I thought I should take the opportunity to try to get a more definite comment on the subject.
Anyone..?

(Could it be so easy that you are further away when you are shooting with a crop body? I.e. less likely to be within 5 feet.)

Jul 01, 2007 at 10:50 AM

tmr4
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p.2 #6 · Where are we with the 50L?

jm42 wrote:
I have seen posts suggesting that there is no focusing problem with the XTi. However, they did not elaborate. And if the problem is focus shift I cannot really see how the XTi could be more successful.
Still, this is high-tech world and almost anything is possible, and clearing the 50L for use with my XTi would be wonderful, so I thought I should take the opportunity to try to get a more definite comment on the subject.
Anyone..?

(Could it be so easy that you are further away when you are shooting with a crop body? I.e. less likely to be within 5 feet.)

I shoot with the XTi and it has the problem within 3 feet or so. I've posted links to my test shots in the post above this.

Jul 01, 2007 at 11:18 PM

mbailey
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p.2 #7 · Where are we with the 50L?

tmr4 wrote:
jm42 wrote:
I have seen posts suggesting that there is no focusing problem with the XTi. However, they did not elaborate. And if the problem is focus shift I cannot really see how the XTi could be more successful.
Still, this is high-tech world and almost anything is possible, and clearing the 50L for use with my XTi would be wonderful, so I thought I should take the opportunity to try to get a more definite comment on the subject.
Anyone..?

(Could it be so easy that you are further away when you are shooting with a crop body? I.e. less likely to be within 5 feet.)

I shoot with the XTi and it has the problem within 3 feet or so. I've posted links to my test shots in the post above this.

I can demonstrate the problem with my 5D using the center focus point but not using the minor focus points. I could not get my XT to show the problem at all. This made me think that the f/2.8 sensitive points had the issue.

Jul 02, 2007 at 03:33 AM

jm42
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p.2 #8 · Where are we with the 50L?

tmr4, one couldn’t possibly get a better analysis of the subject. The effort you have put into the test is highly appreciated!
I guess the only way to overcome the reported discrepancy between chart and real-life results is by trying the lens yourself.

Thanks both of you for your comments!

Jul 02, 2007 at 09:17 PM

zhangp
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p.2 #9 · Where are we with the 50L?

Roy Pertchik wrote:
I e-mailed a Canon insider and learned that there is no new word from Canon since a month ago when they said to expect a public announcement. He recommended:

.... contact our Customer Support Center directly if you wish to pursue the matter:

* E-Mail: Send an email to carecenter@cits.canon.com.

* Telephone: Call Canon’s Customer Support Center toll-free at 1-800-828-4040. Kindly provide the service representative with your contact information, your EF 50mm f/1.2L USM serial number, and details about the focusing issues you are experiencing.

Sounds like it would be productive to remind Canon that there are Canon users who would like to hear a statement.

Any update?

Jul 04, 2007 at 01:58 AM

tmr4
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p.2 #10 · Where are we with the 50L?

mbailey wrote:
tmr4 wrote:
jm42 wrote:
I have seen posts suggesting that there is no focusing problem with the XTi. However, they did not elaborate. And if the problem is focus shift I cannot really see how the XTi could be more successful.
Still, this is high-tech world and almost anything is possible, and clearing the 50L for use with my XTi would be wonderful, so I thought I should take the opportunity to try to get a more definite comment on the subject.
Anyone..?

(Could it be so easy that you are further away when you are shooting with a crop body? I.e. less likely to be within 5 feet.)

I shoot with the XTi and it has the problem within 3 feet or so. I've posted links to my test shots in the post above this.

I can demonstrate the problem with my 5D using the center focus point but not using the minor focus points. I could not get my XT to show the problem at all. This made me think that the f/2.8 sensitive points had the issue.

Very interesting. I recall that you mentioned the XT result before. I also had much better performance using the outer focus points with my XTi and I was speculating that it was a result of some differential masking of problematic light rays before they got to the AF sensor.

Don't some bodies have non-center f/2.8 points. If so it be interesting to see if using them resolves the issue also. If not then that would bump it up as a cause. Not quite sure why it would work that way though, perhaps a problem with the software.

Jul 04, 2007 at 03:26 AM

Gochugogi
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p.2 #11 · Where are we with the 50L?

Don't some bodies have non-center f/2.8 points. If so it be interesting to see if using them resolves the issue also. If not then that would bump it up as a cause. Not quite sure why it would work that way though, perhaps a problem with the software.

Yep, the EOS 3, 1V and all the 1D series sport a cluster of 7 F2.8 cross sensors. The MK3 has even more...

Jul 04, 2007 at 04:52 AM

mh2000
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p.2 #12 · Where are we with the 50L?

>>and a link to my tests:

http://www.pbase.com/tmr4/distance_test

curious... how is backfocus supposed to work in manual focus

?? Your eye *should* be seeing the same thing that your sensor will see... so how is your eye being tricked? I can only image that either your eyes are faulty or your camera is not properly calibrated. AF is of course what it is...

Jul 04, 2007 at 07:02 AM

John P Mulgrew
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p.2 #13 · Where are we with the 50L?

Got the lens but never used it above f/2. Got other lenses for that

Jul 04, 2007 at 10:58 AM

johnastovall
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p.2 #14 · Where are we with the 50L?

I'm sticking with my 50/1.0.

Jul 04, 2007 at 04:21 PM

tmr4
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p.2 #15 · Where are we with the 50L?

mh2000 wrote:
>>and a link to my tests:

http://www.pbase.com/tmr4/distance_test

curious... how is backfocus supposed to work in manual focus

?? Your eye *should* be seeing the same thing that your sensor will see... so how is your eye being tricked? I can only image that either your eyes are faulty or your camera is not properly calibrated. AF is of course what it is...

Sorry, probably using the term manual focus loosely here. Yes my eyes aren't great so for the manual focus shots I did trial shots with manual focus until I got best focus on review at 100%. The difference from the AF setting was very tiny and totaly indistiguishable, to me at least, in the viewfinder. To do better than this I'd need a better focus screen.

Jul 04, 2007 at 04:35 PM

mh2000
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p.2 #16 · Where are we with the 50L?

ok, thanks! Very good test... I was just confused what you were saying about MF. God, why can't they just fix the damn thing!

Jul 04, 2007 at 05:25 PM

tmr4
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p.2 #17 · Where are we with the 50L?

mh2000 wrote:
ok, thanks! Very good test... I was just confused what you were saying about MF. God, why can't they just fix the damn thing!

I realized that I didn't explain MF very well. When I did the manual focus I did it at either f/1.2 or f/2.8 (here adjusting focus at f/2.8 until I got a centered DOF at f/2.8). Thus in MF mode at f/2.8 my XTi showed a forward focus shift (the exact opposite of what occurs with AF (which is of course wide open at f/1.2).

Of course if you MF at the appropriate aperture then you'll have ok focus. My tests were just to show that if you change apertures after achieving focus using MF (say you're using DOF preview button to focus) then you will see the same focus shift.

Jul 20, 2007 at 05:04 AM

wimg
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p.2 #18 · Where are we with the 50L?

Just went through the process of testing and selecting a 50 mm prime, as I have a need for one between the 28 F/1.8 and the 85 F/1.8, to be used as a low light, fast lens, at F/1.x to F/2.

1. 50 F/2.5 CM - very sharp from max aperture, but not fast enough
2. 50 F/1.8 Mk II - ok-ish, but build quality is appalling
3. 50 F/1.4 - only sharp from F/4 and upwards, although very sharp there, BQ not really very good: the inner barrel containign the optics wobbles quite a bit
4. 50 F/1.2 - lovely lens in daylight, object distances of 4-5 m and further away, from full opening, amazing IQ and BQ, much, much sharper and better IQ you'd expect reading all the reviews and tests. However, nearby, and low light, it is a disaster. Backfocus at any light except fluorescent light, where it goes to frontfocus, and MF is off at the nearby distances, and that is using an Angle Finder C at 2.5X magnification. This also seems to depend on the contrast of the frame you're trying to capture. Only medium contrast captures seem to do well.

BTW, I have tried several copies of the 1.8, 3 of the 1.4, and also 3 of the 1.2, shooting > 1000 test shots, and getting so desparate I even re-calibrated the 400D myself, and got a second body that wasn't calibrated except to standard factory specs.

I gave up, for now anyway. I may try a last time, with a lens from a different supplier, to see if it wasn't just a bad batch.

Kind regards, Wim

Jul 20, 2007 at 07:32 PM

mh2000
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p.2 #19 · Where are we with the 50L?

hahaha! I like your assessment of the 50/1.8 as being "ok-ish"

...I tend to think of it as "fine" as in "it's *just* fine," nothing more... but over a lot of photos I find it more reliably "fine" than my 50/1.4 was. FWIW, my TS-E 45 is very nice.

in the same boat...

Jul 21, 2007 at 12:04 AM

SoundHound
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p.2 #20 · Where are we with the 50L?

I had the same reactions as wimg to Canon's 50mm line-up. But I never shot with my 50L in dim light ML under controlled conditions (I shoot fast moving dancers and get a lot of OOFs).
I bought my 50L to use with my 5D which I must MF focus in very dim light (can't use the central AF sensor of the 5D which is the only one to work).

Now that I have the MkIII and use its wonderful AF I haven't used the 50L much because the (effective) FL of 64mm is not useful. Neither is the F 1.2/1.4 stop required because I set the MkIII's ISO one stop faster (3200). So maybe I should replace my 50L with a 1.8?

Jul 21, 2007 at 03:54 PM

mh2000
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p.2 #21 · Where are we with the 50L?

I ditched my 50/1.4 for the 1.8 and am happier with the results. Low light focusing is better, I don't get the hunt cycles that the 1.4 is so good at getting into... and I just prefer the look, even if it isn't quite as sharp... I just find it more pleasing for the subjects I shoot.

Jul 21, 2007 at 06:32 PM


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