Mitch W wrote:
I'm CPS Gold and ended up paying around $240 for the fix. Steep, but it went from being a barely used lens to my most used lens, so in the end it was worth it.
I did the same thing, I sent it in and they charged me to say it's up to specs. I even had a note in there that I used it on the MKIV, 1DsMKIII and 1DX and that it was very soft but they still said up to specs. Spent that money for nothing! They don't have anything to test these lenses on at the facility?
John P Mulgrew wrote:
I did the same thing, I sent it in and they charged me to say it's up to specs. I even had a note in there that I used it on the MKIV, 1DsMKIII and 1DX and that it was very soft but they still said up to specs. Spent that money for nothing! They don't have anything to test these lenses on at the facility?
the same experience to me. I send it in with 1D X, they said its perfect but to me, I'm not satisfied when using AF.
I consider to sell my 2e 50/1.2 again.
John P Mulgrew wrote:
I did the same thing, I sent it in and they charged me to say it's up to specs. I even had a note in there that I used it on the MKIV, 1DsMKIII and 1DX and that it was very soft but they still said up to specs. Spent that money for nothing! They don't have anything to test these lenses on at the facility?
I don't see any sense in sending lenses and bodies for calibration to a Canon facility. I am using the 50/1.2 on two 5D MkII camera bodies, and the MFA number is very different in each body with the same lens. There are very small mechanical differences especially in the camera bodies which change the distance to the film/sensor plane. The MFA is supposed to take care of those differences (including differences in lens copies). I assume that Canon does nothing else with a specific in-house software what you can do yourself with a commercial MFA program.
I thought about selling this lens but how can I sell something I know doesn't work as it should?
I'm going to go outdoors today and just play around with it to see if the FoCal really did help.
John P Mulgrew wrote:
I did the same thing, I sent it in and they charged me to say it's up to specs. I even had a note in there that I used it on the MKIV, 1DsMKIII and 1DX and that it was very soft but they still said up to specs. Spent that money for nothing! They don't have anything to test these lenses on at the facility?
I walked my lens into the Hollywood CA CPS facility (they accept only drop offs at this location). Before taking the lens (and my money) they in put it on a 5D3 and confirmed its softness on the outer points. If it had been sharp I guess I would have just taken the lens and left and saved the $240. I guess I now understand the value of being able to walk the repair in as opposed to sending it in (I realize most aren't able to do this though).
Gust wrote:
but how to deal with backfocus at short distances?
is there a solution?
thnx
Gust, i would offset that back focus by not using the center Af point for your AFMA process. It is strange that you have to do this with 1Dx? my 1Ds2 handle the 50L pretty well in any subject distance.
It might be a bit tricky to accurately MFA this lens at f/1.2 even with FocalPro. I recommend very good and consistent lighting (studio lights preferred). Run this a couple of times, if the measured MFA numbers are too different, then you might want to do it at f/1.4 or f/1.8 just as a comparison if those numbers line up with some of the ones measured earlier. Around f/2.0 it shouldn't be a problem at all.
Center focus is normally okay to use, but sometimes it also helps to allow other AF points for accuracy.
mttran wrote:
Gust, i would offset that back focus by not using the center Af point for your AFMA process. It is strange that you have to do this with 1Dx? my 1Ds2 handle the 50L pretty well in any subject distance.
my X and the 1.2 are together adjusted by Canon Europe in Germany.
the lens was a little out of focus, but not much, said the cps man.[ after that it was ok]
when I put the combo now on a tripod and using the AF by 1.2 its in focus [ but a little soft, but its in focus]
every time I close the aperture from 1.2 to 1.4 and up to 2.8, the [in] focus moves with every 1/3 stop further away from the original focus point.[ focus distance ca 1-1,5 meter
At 4.0 its gone and every thing is fine.
Most of the time I use the 1.2 in Studio at 8.0 and here he's superb.
So, I hardly can live with that back focus. Thats why I sold my first 1.2 one year ago.
I love that lens for his colours and depth of field, but....
Gust, how about this: your 50L default focal plan is an "U" shape, at center point the focal plane will not be shifted regardless aperture and distance setting. Do the normal AFMA using center point then manualy offset the back focus during your shooting:
1) If center point used: Shoot normal like the eyes for your focal plane
2) If off center point used: Depending how far from center point - pick the nose/chin/front head to offset the back focus
Cheap way to fix the problem your having when dealing with "U" shape focal plane lenses. 50L in this case. I would think 1DX cover this scenario since my 1Ds2 has it in its AF database.
Please note: it is not the lens that shifts your focal plane, it's the body. Its AF that can not handle the "U" shape focal plane when using off center AF point. All fat and short focal length lenses have this "U" shape and the 50L has the deepest "U" shape by design. However, 50L firmware can be modifed to offset the body AF back focus error.
mttran wrote:
Please note: it is not the lens that shifts your focal plane, it's the body. Its AF that can not handle the "U" shape focal plane when using off center AF point. All fat and short focal length lenses have this "U" shape and the 50L has the deepest "U" shape by design. However, 50L firmware can be modifed to offset the body AF back focus error.
Thank you for explain me how it works. Didn't understand it at all before.
I will go back to cps and ask them to modify the firmware, thats what you mean?
This one IS SHARP! I tested 3 at my dealer shop. They all where horrible right out of the box. My dealer asked me to come back and have another try, when he gets a new production charge ... after he has sold the lenses!
How to deal with 50mm or shorter focal length that is faster than f1.8. By default, most of them project a 3D light object in an oval shape like your cheerios bowl. How deep the oval shape is depending on how fast is the lens. This 3D light object is flatter and flatter at its edge when the lens aperture is stopping down and soon it will be 2D light object like your dinner plate at some aperture around f2.8 –f4.0.
While your lens at this optical bending effects, your final focal plane still stay the same at your (AF) focus point which in turn your camera captures an image after the optical bending effects.
Bang …man, this stupid 50L give me some back focus image again.
Another word you have tried to capture an object that has been moved after AF confirmation. Ok, then how we deal with these scenarios
a. Wide open: shoot normal since there is no optical shift in this case
b. Stop down aperture:
i. Center AF point: shoot normal regardless your aperture setting since your focal plane and optical plane should be in line at its center point … no focus plane shifting here… so no back focus issue in this case.
ii. Off Center AF point: expected back focus issue and this can be offset by
1. Work with what you have: predict the final optical effects and adjust your focus point like nose, chin, front head, etc…which is depending on your subject distance and aperture setting.
2.Install focusing screen and manually adjust the focal plane after AFed.
3.Send the body and lens in for fast lens optical effects calibration
I struggle with it as well. No matter what I seem to try it seems to fall a little short, that's after going back to Canon, where I expected them to send me a new lens. I run focal on it, though I think I may have to try it in a better lighting setup. This is on a 5Dii btw.
Ralph Conway wrote:
This one IS SHARP! I tested 3 at my dealer shop. They all where horrible right out of the box. My dealer asked me to come back and have another try, when he gets a new production charge ... after he has sold the lenses!
Do you really believe that three lenses in a row are unsharp? No way. Sounds more like severe user error to me, sorry. AF at f/1.2 was fairly bad before I microfocus adjusted this lens. Now it is very good with center focus at f/1.2. If I would have tested this lens just by attaching it to my camera in a shop, I could have also said how "horrible" this lens is.
50L is no doubt a razor sharp lens if used correctly. Most don't see this since 50L 1/3 shallow dof @wideopen is quite challenging for any AF bodies. It's always the AF and/or calibration fault but not the lens and that is what i have found so far
retrofocus wrote:
Do you really believe that three lenses in a row are unsharp? No way. Sounds more like severe user error to me, sorry. AF at f/1.2 was fairly bad before I microfocus adjusted this lens. Now it is very good with center focus at f/1.2. If I would have tested this lens just by attaching it to my camera in a shop, I could have also said how "horrible" this lens is.
A harsh comment imo, retrofocus. I did not believe it. I knew it.
I spend about two and a half hours at my dealers place and we did the lens tests together (all wide open of course), handhold AND using a tripod. One lens was always wrong with AF. The second one was really good in sharpness (hits AF about 80%). The third one did less than 50% at easiest conditions (high contrast and plenty of light).
We used centerpoint only and controlled only the center of the frame, too. I used my 5D II checked and calibrated by Canon that worked excellent with my 24-105, 100 L, 70-200 4.0 (all out of the box). I would have purchased the second lens (80% in AF is an excellent hit quote for a lens like this, imo). But like the other good one it had an unbelieveable high chromatic aberation (15-20 pixels - of course we watched our test shots zoomed in at 100%).
That is why I called THOSE THREE lenses "horrible". They just where. You may look for failures on your own. I myself do, too. But I would not purchase a 100$ lens, that I can not use. And I surely will not spend € 1.400€ for an L to put it into my vitrine.
Instead of the 1.2 I purchased the best 1.4 they had. Great IQ, but not very usefull for MF.
