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Archive 2010Post your 50L failures please
p.3 #1Post your 50L failures please
I haven't owned either and you won't hear me saying the the 50/1.0L is amazing... I just don't think the bokeh in samples I've seen is all that good... but I was shooting Canon back when the 50/1.0L was released so it wasn't "mythological creature" when I first looked into it... so I was more logic in my assessment of it...
the documented problem zone of the 50/1.2L are right in the area that *I* want to shoot so I'm not trying one... (I don't need f1.0 or f1.2 either)...
PetKal wrote:
In addition, everyone seems to feel qualified to utter verdicts on the 50 f/1.0 performance. 
the documented problem zone of the 50/1.2L are right in the area that *I* want to shoot so I'm not trying one... (I don't need f1.0 or f1.2 either)...
PetKal wrote:
deepbluejh wrote
The 50/1.0L is a mythological creature. It's something that practically no one has ever used, yet everyone seems to think it's amazing. Truth is, the current 50/1.2L is better in almost every way (including optical quality in most situations). Additionally, copy variation was a *serious* problem with the 50/1.0L. May 23, 2010 at 11:29 PM
p.3 #2Post your 50L failures please
Actually, this isn't really true.
mttran wrote:
Man with best light always win
mttran wrote:
Man with best light always win
May 23, 2010 at 11:30 PM
p.3 #3Post your 50L failures please
Based on my experience with 4 copies of this lens, everything in this thread is correct (well, except for the focus shift part).
An improperly working copy of this lens can indeed produce rubbish, but one that is working "as designed" can be magic.
Still haven't seen a focus shift at different apertures though.
An improperly working copy of this lens can indeed produce rubbish, but one that is working "as designed" can be magic.
Still haven't seen a focus shift at different apertures though.
May 24, 2010 at 06:56 AM
p.3 #4Post your 50L failures please
garyvot wrote:
Still haven't seen a focus shift at different apertures though.
Did you ever test for it?
And I have to ask - why four copies?
Still haven't seen a focus shift at different apertures though.
Did you ever test for it?
And I have to ask - why four copies?
May 24, 2010 at 07:37 AM
p.3 #5Post your 50L failures please
Link to a series of shots I took from f/1.2 to 8.0. You be the judge of the focus shift issue. I've never experienced any unsharpness, color fringing or glowing edges at any apertures.
https://www.fredmiranda.com/forum/topic/752137/0#6858481
https://www.fredmiranda.com/forum/topic/752137/0#6858481
May 24, 2010 at 08:02 AM
p.3 #6Post your 50L failures please
J. Allen wrote:
Link to a series of shots I took from f/1.2 to 8.0. You be the judge of the focus shift issue. I've never experienced any unsharpness, color fringing or glowing edges at any apertures.
https://www.fredmiranda.com/forum/topic/752137/0#6858481
+1, great test Allen and thanks for sharing
In real life with high contrast or busy background, Light at f2.8 or larger (with short focal length) does make the AF sensor hiccup and cheapo AF firmware choke then some unexpected results as some (F/B) shifting. See my comment and samples last post. So, don't be confused with focus shifting term in these cases.
Blamed it on your camera
Edited on May 24, 2010 at 01:06 PM · View previous versions
Link to a series of shots I took from f/1.2 to 8.0. You be the judge of the focus shift issue. I've never experienced any unsharpness, color fringing or glowing edges at any apertures.
https://www.fredmiranda.com/forum/topic/752137/0#6858481
+1, great test Allen and thanks for sharing
In real life with high contrast or busy background, Light at f2.8 or larger (with short focal length) does make the AF sensor hiccup and cheapo AF firmware choke then some unexpected results as some (F/B) shifting. See my comment and samples last post. So, don't be confused with focus shifting term in these cases.
Blamed it on your camera
Edited on May 24, 2010 at 01:06 PM · View previous versions
May 24, 2010 at 12:51 PM
p.3 #7Post your 50L failures please
mttran wrote:
https://www.fredmiranda.com/forum/topic/752137/0#6858481+1, great test Allen and thanks for sharing
In real life with high contrast or busy background, Light at f2.8 or larger (with short focal length) does confuse the AF sensor and cheapo AF firmware sometime choke then some unexpected results as some (F/B) shifting. See my comment and samples last post. So, don't be confused.
Are you suggesting that the focus shift is simply a coincidence experienced by a large number of users at specific distances and apertures and is more likely due to AF sensor and or firmware issues than a design flaw?
J. Allen wrote
Link to a series of shots I took from f/1.2 to 8.0. You be the judge of the focus shift issue. I've never experienced any unsharpness, color fringing or glowing edges at any apertures.https://www.fredmiranda.com/forum/topic/752137/0#6858481
In real life with high contrast or busy background, Light at f2.8 or larger (with short focal length) does confuse the AF sensor and cheapo AF firmware sometime choke then some unexpected results as some (F/B) shifting. See my comment and samples last post. So, don't be confused.
Are you suggesting that the focus shift is simply a coincidence experienced by a large number of users at specific distances and apertures and is more likely due to AF sensor and or firmware issues than a design flaw?
May 24, 2010 at 01:06 PM
p.3 #8Post your 50L failures please
M Vers wrote:
https://www.fredmiranda.com/forum/topic/752137/0#6858481+1, great test Allen and thanks for sharing
In real life with high contrast or busy background, Light at f2.8 or larger (with short focal length) does confuse the AF sensor and cheapo AF firmware sometime choke then some unexpected results as some (F/B) shifting. See my comment and samples last post. So, don't be confused.Are you suggesting that the focus shift is simply a coincidence experienced by a large number of users at specific distances and apertures and is more likely due to AF sensor and or firmware issues than a design flaw?
It is not 100% proof, I have no F/B focus shift at any distance with my 1Ds2 at all but trouble some with my 5D and 5D2
mttran wrote
J. Allen wrote
Link to a series of shots I took from f/1.2 to 8.0. You be the judge of the focus shift issue. I've never experienced any unsharpness, color fringing or glowing edges at any apertures.https://www.fredmiranda.com/forum/topic/752137/0#6858481
In real life with high contrast or busy background, Light at f2.8 or larger (with short focal length) does confuse the AF sensor and cheapo AF firmware sometime choke then some unexpected results as some (F/B) shifting. See my comment and samples last post. So, don't be confused.
It is not 100% proof, I have no F/B focus shift at any distance with my 1Ds2 at all but trouble some with my 5D and 5D2
May 24, 2010 at 01:14 PM
p.3 #9Post your 50L failures please
i want the last two minutes of my life back.
May 24, 2010 at 01:21 PM
p.3 #10Post your 50L failures please
abam wrote:
i want the last two minutes of my life back.
Do you want the few seconds it took you to type that out back, too?
i want the last two minutes of my life back.
Do you want the few seconds it took you to type that out back, too?
May 24, 2010 at 01:31 PM
p.3 #11Post your 50L failures please
Sorry everyone gets so hot under the collar about this. It certainly wasn't my intention to cause any harrumphing.
Many thanks to those who've posted such useful pictures and links, and special thanks to J. Allen for quantifying the focus shift.
My feeling now is that this lens is something that would suit me, and its minor failings are things I should be able to work around without too much hassle. I'm off to try the lens at a dealer tomorrow.
Many thanks to those who've posted such useful pictures and links, and special thanks to J. Allen for quantifying the focus shift.
My feeling now is that this lens is something that would suit me, and its minor failings are things I should be able to work around without too much hassle. I'm off to try the lens at a dealer tomorrow.
May 24, 2010 at 01:40 PM
p.3 #12Post your 50L failures please
M Vers wrote:
Are you suggesting that the focus shift is simply a coincidence experienced by a large number of users at specific distances and apertures and is more likely due to AF sensor and or firmware issues than a design flaw?
An optical design flaw can be easily compensated with a response curve flashed by factory. IMO, 50L mystery is more than the lens itself. So, it depends what body you have integrated with...
Are you suggesting that the focus shift is simply a coincidence experienced by a large number of users at specific distances and apertures and is more likely due to AF sensor and or firmware issues than a design flaw?
An optical design flaw can be easily compensated with a response curve flashed by factory. IMO, 50L mystery is more than the lens itself. So, it depends what body you have integrated with...
May 24, 2010 at 03:56 PM
p.3 #13Post your 50L failures please
mttran wrote:
An optical design flaw can be easily compensated with a response curve flashed by factory.
Assuming you are speaking of focus shift and not "optical design flaws" in general, how exactly do you propose this compensation should work? In particular, do you suggest that the adjustment to the focus should be made during the AF search, while the lens is wide open, or after the search but just prior to exposure?
The focus shift issue doesn't go away by simply compensating in firmware because there isn't really a suitable moment prior and up to exposure that such a compensation could be made. If you do it "in advance"--i.e., during the AF procedure--then changes in f-number or subject distance that may occur may also require additional recalculation and adjustment. For example, how would the system handle Tv? Metering changes will change selected f-number. On the other hand, if the system waits until the shutter press to recalculate--i.e., you have committed to an f-number, shutter speed, and subject distance, and so the degree of focus shift is known--then any further focus adjustment introduces an additional delay which no matter how small, is undesirable.
An optical design flaw can be easily compensated with a response curve flashed by factory.
Assuming you are speaking of focus shift and not "optical design flaws" in general, how exactly do you propose this compensation should work? In particular, do you suggest that the adjustment to the focus should be made during the AF search, while the lens is wide open, or after the search but just prior to exposure?
The focus shift issue doesn't go away by simply compensating in firmware because there isn't really a suitable moment prior and up to exposure that such a compensation could be made. If you do it "in advance"--i.e., during the AF procedure--then changes in f-number or subject distance that may occur may also require additional recalculation and adjustment. For example, how would the system handle Tv? Metering changes will change selected f-number. On the other hand, if the system waits until the shutter press to recalculate--i.e., you have committed to an f-number, shutter speed, and subject distance, and so the degree of focus shift is known--then any further focus adjustment introduces an additional delay which no matter how small, is undesirable.
May 24, 2010 at 04:23 PM
p.3 #14Post your 50L failures please
wickerprints wrote:
Assuming you are speaking of focus shift and not "optical design flaws" in general, how exactly do you propose this compensation should work? .
Zeroed out the USM loop errors that’s reported by the cam body to stop the motor outside its spec to compensate the optical focus shift. This compensation curve can be plotted in the lab based on (aperture, distance, …etc) of the lens then re-flash back to the lens to work with body AF firmware.
mttran wrote
An optical design flaw can be easily compensated with a response curve flashed by factory.Assuming you are speaking of focus shift and not "optical design flaws" in general, how exactly do you propose this compensation should work? .
Zeroed out the USM loop errors that’s reported by the cam body to stop the motor outside its spec to compensate the optical focus shift. This compensation curve can be plotted in the lab based on (aperture, distance, …etc) of the lens then re-flash back to the lens to work with body AF firmware.
May 24, 2010 at 05:42 PM
p.3 #15Post your 50L failures please
mttran wrote:
Zeroed out the USM loop errors that’s reported by the cam body to stop the motor outside its spec to compensate the optical focus shift. This compensation curve can be plotted in the lab based on (aperture, distance, …etc) of the lens then re-flash back to the lens to work with body AF firmware.
You didn't address the heart of my previous post, which is not how the correction takes place but when. To say that this kind of compensation can be done as a part of the usual AF system algorithm is incorrect, for the reasons I already provided.
AF microadjustment at present doesn't even take into account focus distance or focal length variation within a single lens. You think it is more feasible to rewrite the AF algorithm for a focus shift issue in one lens when the sensible thing to do is to simply redesign the optics to correct the focus shift in the first place?
Canon deliberately designed the EF 50/1.2L with the focus shift, not because they wanted to cut corners. It's not like the lens would have been twice as expensive had it been designed with floating elements. The reason they did it was because the intentional spherical aberration gives it the most pleasing background blur. They discontinued the EF 50/1.0L but in order to create an f/1.2 successor that had comparable blur quality, they let it have more pronounced focus shift. That is why it exists the way it does.
Zeroed out the USM loop errors that’s reported by the cam body to stop the motor outside its spec to compensate the optical focus shift. This compensation curve can be plotted in the lab based on (aperture, distance, …etc) of the lens then re-flash back to the lens to work with body AF firmware.
You didn't address the heart of my previous post, which is not how the correction takes place but when. To say that this kind of compensation can be done as a part of the usual AF system algorithm is incorrect, for the reasons I already provided.
AF microadjustment at present doesn't even take into account focus distance or focal length variation within a single lens. You think it is more feasible to rewrite the AF algorithm for a focus shift issue in one lens when the sensible thing to do is to simply redesign the optics to correct the focus shift in the first place?
Canon deliberately designed the EF 50/1.2L with the focus shift, not because they wanted to cut corners. It's not like the lens would have been twice as expensive had it been designed with floating elements. The reason they did it was because the intentional spherical aberration gives it the most pleasing background blur. They discontinued the EF 50/1.0L but in order to create an f/1.2 successor that had comparable blur quality, they let it have more pronounced focus shift. That is why it exists the way it does.
May 24, 2010 at 05:46 PM
p.3 #16Post your 50L failures please
wickerprints wrote:
"You didn't address the heart of my previous post, which is not how the correction takes place but when. To say that this kind of compensation can be done as a part of the usual AF system algorithm is incorrect, for the reasons I already provided."
==> I thought I did, since the USM compensation curve can be embedded in the lens IC to work with body AF in realtime.
AF microadjustment at present doesn't even take into account focus distance or focal length variation within a single lens. You think it is more feasible to rewrite the AF algorithm for...Show more →
+1, I am glad you point this out since i am not aware of it. Do we have any documentation from Canon about this feature and why so many of us against it.
like i said earlier, 50L mystery is more than the lens itself...
mttran wrote
Zeroed out the USM loop errors that’s reported by the cam body to stop the motor outside its spec to compensate the optical focus shift. This compensation curve can be plotted in the lab based on (aperture, distance, …etc) of the lens then re-flash back to the lens to work with body AF firmware.==> I thought I did, since the USM compensation curve can be embedded in the lens IC to work with body AF in realtime.
AF microadjustment at present doesn't even take into account focus distance or focal length variation within a single lens. You think it is more feasible to rewrite the AF algorithm for...Show more →
+1, I am glad you point this out since i am not aware of it. Do we have any documentation from Canon about this feature and why so many of us against it.
like i said earlier, 50L mystery is more than the lens itself...
May 24, 2010 at 06:40 PM
p.3 #17Post your 50L failures please
No, you did not address the issue. If you work the compensation for focus shift into the AF algorithm, it is highly nontrivial to do this if your subject distance is changing AND your f-number is not fixed. Furthermore, even if these things are not changing, once AF acquires focus, it may not appear to be focused when you look through the viewfinder, due to the fact that the VF shows you the image wide open.
It is not so simple to think that focus shift compensation via modifying AF is simply looking up a curve or a table.
As for documentation, I have no proof. But given that Canon is clearly able to design lenses with very large apertures with floating elements (EF 85/1.2L II), and that the 50/1.0L did not exhibit focus shift either, it is likely that a very intentional design decision was made to permit it in the 50/1.2L. It is not as if lens design just spits out something and only later do the engineers realize "oops, we made a mistake." These designs are created through extensive computer simulation. It is simply impossible that the engineers were unaware of the focus shift. And since it is not costly to correct for it, the only conclusion is that it was left in there intentionally.
Furthermore, note that it is undercorrected, not overcorrected, meaning that blur discs behind the plane of focus appear softer-edged, rather than the blur discs in front of the plane of focus. This lends support to the purposefulness of this design.
Those who dislike the focus shift are people who generally are not using the lens as it was intended. Judging from the results that some people are able to get from this lens, I can only remind people of the old adage that success is about the photographer, not the equipment.
It is not so simple to think that focus shift compensation via modifying AF is simply looking up a curve or a table.
As for documentation, I have no proof. But given that Canon is clearly able to design lenses with very large apertures with floating elements (EF 85/1.2L II), and that the 50/1.0L did not exhibit focus shift either, it is likely that a very intentional design decision was made to permit it in the 50/1.2L. It is not as if lens design just spits out something and only later do the engineers realize "oops, we made a mistake." These designs are created through extensive computer simulation. It is simply impossible that the engineers were unaware of the focus shift. And since it is not costly to correct for it, the only conclusion is that it was left in there intentionally.
Furthermore, note that it is undercorrected, not overcorrected, meaning that blur discs behind the plane of focus appear softer-edged, rather than the blur discs in front of the plane of focus. This lends support to the purposefulness of this design.
Those who dislike the focus shift are people who generally are not using the lens as it was intended. Judging from the results that some people are able to get from this lens, I can only remind people of the old adage that success is about the photographer, not the equipment.
May 24, 2010 at 07:22 PM
p.3 #18Post your 50L failures please
i really wish this lens didn't suck 
all @ 2.0:
all @ 2.0:
May 24, 2010 at 08:16 PM
p.3 #19Post your 50L failures please
That it can perform pretty well wide open, or nearly wide open, was never the issue.
That said, the charts at The Digital Picture seem to show the 50/1.4 a shade better at comparable apertures.
That said, the charts at The Digital Picture seem to show the 50/1.4 a shade better at comparable apertures.
May 25, 2010 at 01:17 AM
p.3 #20Post your 50L failures please
A well calibrated 50/1.4 is certainly worthwhile.
I'm defintely keeping mine, which is spot on even at f/1.4
At this price and quality level I'd be crazy to sell it.
Ruy
I'm defintely keeping mine, which is spot on even at f/1.4
At this price and quality level I'd be crazy to sell it.
Ruy
May 25, 2010 at 03:47 AM