do you own a sharp copy

i'm always reading about people having the same lens 2and 3 times because they don't think its a sharp or true as they would like ! you would think canon would have more then the experience needed by now to make there lenses spot on,an talking about there L-lenes line up, is it just PP people or did they truly get a bad copy of the 1st lens bought! i think what i'm asking dose canon make bad copy's of there L lenses series,any thoughts on this,thanks guys.

In my experience, I have never had a "bad" copy - many lenses just need to be calibrated to the body they are using - using AFMA or being sent into canon for calibration.

Lots of contributing factors here. These are still mass produced objects and even the most rigorous inspection and quality control will result in minor variations within the tolerances. The problem may not rest entirely with the lens. A body thats within the tolerances but slightly front focuses gets mounted on a body thats also slightly off can result in unacceptable results. Micro focus adjust has helped some of that problem but also confirms variations. Through use and wear lenses may go soft and need calibration. And lastly some users are a bit too paranoid about sharpness while not having a good method of testing. These forums are filled with examples of users who bought a lens and put it through some unrealistic or technically unsound testing methodology. So to sum it up, yes it happens and yes sometimes its exaggerated.

There are only 5 super secret special sharp copies of each lens out there, the rest are slowly softer and softer the more of that lens canon made, therefore, the newer productiondate of an old lens design will be horrible, Hence, why people hate the 17-40, 50 1.2, 85 1.4. These are all super soft lenses that are completely horrible always, unless you have a unicorn.

So these people that have second and third copies are magicians who clone the lenses hoping to get less dull edges and really sharp glass, they frequently cut themselves on the sharp glass and they drop it, this process repeats itself until the magician learns to attach a lens hood, protecting his fingers.

I had a whole herd of unicorns. The Troll I hired to protect them from Sasquatch sold them to a magician for a couple of kids named Hansel & Gretel. Why did I trust my precious 'corns to that damn knuckle-dragging, bridge-dwelling, child-eating, Nikon-shooting Troll?

I must just be lucky, I've never had a bad lens, never micro adjusted anything, to my eye everything comes out of the box as it should. Once I fell into this good/bad copy trap and shot all kinds of tests with my 70-200, eventually I figured out how to use the lens correctly though and found the problem was me, not Canon's terrible and shoddy quality control, LOL

Like anything there will be lenses that aren't up to snuff, but they are not very prevalent. There are for sure people that overthink things with lenses and think they have a bad copy when in reality they could just micro adjust the lens and it would be stellar. Or people that take uncontrolled test shots and then think the next lens is good yet they used completely different setting and shooting conditions. I've personally never had a bad lens from Canon. I've owned at one time or another virtually every non super telephoto lens Canon has had out in the past 15 years. Frequently, several copies of the same lens.

Some interesting reads.
http://www.lensrentals​.com …s-is-soft-and-other-myths
http://www.lensrentals​.com …lens-and-camera-variation
http://www.lensrentals​.com …s-is-soft-and-other-facts

My experience is that before I had bodies with MFA nearly 1/2 of my lenses went back to Canon for adjustment as I could easily see that they were not performing to my expectations. Sometime it helped and sometime it wouldn't. However, now with MFA I have found that lenses I previously thought were not performing as well as I expect performed much better once I went through and calibrated them to the body.

What is AFMA and MFA I read about in this thread?

I am assuming it is calibrating the lens to the body which can be done in some bodies. I know it can not be done with the 60D which I own sadly....

Inspeqtor wrote in post #17205487
What is AFMA and MFA I read about in this thread?

I am assuming it is calibrating the lens to the body which can be done in some bodies. I know it can not be done with the 60D which I own sadly....

Micro focus adjustment. It allows a lens to be calibrated to the body. For an example, below is my 100-400 with no adjustment applied and then with a +10. Looking at the image as a whole it still looked good with it adjusted to zero but a little soft. Adjusted the lens was so much sharper. It was like shooting with a different lens.

gjl711 wrote in post #17205414
My experience is that before I had bodies with MFA nearly 1/2 of my lenses went back to Canon for adjustment as I could easily see that they were not performing to my expectations. Sometime it helped and sometime it wouldn't. However, now with MFA I have found that lenses I previously thought were not performing as well as I expect performed much better once I went through and calibrated them to the body.

Same here. I've done MTF tests on my L glass just to see if I have any decentering issues or focusing problems at different zoom positions. All of them so far have met or exceeded the specs.

Micro adjustment (MA) adds or subtracts a small value when the lens is focusing, to compensate for the fact that the distance from the subject to the AF sensor is not identical to the distance from the subject to the focal plane. If your camera and lens are at the limits of the specification, in opposite directions, you can have noticeable focus errors using the combination without either of them being "out of calibration" individually.

Its funny I bought a refurbed 400 5.6 and I have a 100-400. Trouble was when I tried the 400 5.6 with my 1DMKII, it kept front focusing, by maybe 2 inches. I called canon and they said well send it back or send it in and have it calibrated.
I sent it in and got it back and tried again, now it backfocused by about an inch.
So I sent it back. I was basically convinced that a 400 prime would be sharper than my 100-400, but not this time, at least in my case.

You should be able to microadjust that difference out with no problems. If you didn't send Canon the lens and the camera at the same time, there's no way they could calibrate the lens to match it.

As someone previously said, of course out of the huge amount of lenses Canon manufacture there are going to be some duffers, like any mass produced product. I think I've been quite lucky as I haven't had the misfortune of getting a lemon in the 30+ years of buying lenses. Also, since the advent of the micro adjust feature on Canon bodies, front and back focus issues are less of a problem.

I will say though that people who keep posting to forums saying that it took them 2,3 or 4 samples to "get a good copy" have a serious OCD problem! For some it happens EVERY time they buy a lens and to me that's not rational behaviour.

blanex1@netzero.com wrote in post #17205274
i'm always reading about people having the same lens 2and 3 times because they don't think its a sharp or true as they would like ! you would think canon would have more then the experience needed by now to make there lenses spot on,an talking about there L-lenes line up, is it just PP people or did they truly get a bad copy of the 1st lens bought! i think what i'm asking dose canon make bad copy's of there L lenses series,any thoughts on this,thanks guys.

The problem isn't necessarily the lens itself, it also has to do with the body. Both have manufacturing tolerances in the thickness of the mount, the positioning of the sensor, etc. If you can't MFA a lens, you have to try multiple copies to get one that works with your body.

In my case, all my lenses but one front focus just a bit. That tells me that the problem isn't in the lens, but rather the body.