"...How many of you out there fine tune your lenses?"
Jules you might be better served if your stated this as how many who work commercially fine tune your lenses... Lots of opinions so far, very little validation of inferences...

Jules I don't have deep pockets and my client work demands commercial quality... To this end I check ALL my lenses whether they are Nikkors, Sigma or Tokina glass... I have and shoot all these optics... for the most part of my newer Nikkors tend to be very close... However I purchase a lot of older kit... Since I shoot primarily fashion and portraiture I'm heavy into the 80-200mm focal range... my primes are either f/1.4 or f/1.8 while zoom optics are nearly all f/2.8.

Please realize that it's very easy to mess up trying to fine-tune... You seriously need to double check your results with LiveView which btw is ALWAYS in focus... Most folks are naive about contrast detect verses phase detect thus are clueless why they seriously need to verify their efforts... Trust but verify...

Just so you know I'm not simply bringing my "opinions" to the table.. Below please find a target from "tuning" an epic "mint" AF 80-200mm f/2.8 one-touch I purchased for $280... There are vintage gems like this on eBay, if you know what you're buying... So in this case I scored a fabulous portrait lens at a fraction of a new Nikkor... Albeit it certainly had a back-focus issue that was correctable... you mileage may vary...

Oh, btw, the newest Nikon FF bodies now allow you to Fine-Tune at both ends of a zoom optic... Sweet!
The D6 and D780 have this feature... If in doubt Fine-Tune for the FL you use the most... In my case for fashion editorials and portraiture, it's 135mm (mid-way between min and max) on my 80-200mm; 70-200 and 70-210mm glass. Which I've found to be a universal "Sweet Spot" for most zooms in this range.

Hope this helps and maybe take the other "opinions" here with a proverbial "grain of salt"
Please have a Happy Holiday Season and a wonderful New Year ahead Julies
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Every Manufacturer added the AF fine tune feature to DSLRs because all manufacturered items have tolerances, Cameras & Lenses are no exception. By and large they do a very good job but occasionally the DSLR is at one end of the allowable Tolerance and a given lens may be at the other. In this instance focus accuracy can be improved with AF Fine tuning. Doing the test (which is easy to do manually or with one of the automatic applications) lets you know how your cameras & lenses match up. Ive done it on many cameras and many lenses, both Nikon & Canon on cameras that are used professionally. Most times, I have found adjustment is not needed, but Sometimes it is and in those cases it can help a great deal. It mystifies me why this is a controversial topic?
There are no rules, If you choose not to do it, or don't feel you need it, that is perfectly fine. Many folks have seen it work, so they test. The Manufacturers created the adjustment because they saw a clear need. If you test enough cameras & Lenses you will find some that need it. But if you have cameras & lenses that perform well out of the box, thats a good thing. But it does not mean that the adjustment is useless.
My experience tells me that it CAN be helpful in some cases, and in my view, Knowing is better than not knowing.

Every Manufacturer added the AF fine tune feature to DSLRs because all manufacturered items have tolerances, Cameras & Lenses are no exception. By and large they do a very good job but occasionally the DSLR is at one end of the allowable Tolerance and a given lens may be at the other. In this instance focus accuracy can be improved with AF Fine tuning. Doing the test (which is easy to do manually or with one of the automatic applications) lets you know how your cameras & lenses match up. Ive done it on many cameras and many lenses, both Nikon & Canon on cameras that are used professionally. Most times, I have found adjustment is not needed, but Sometimes it is and in those cases it can help a great deal. It mystifies me why this is a controversial topic?
There are no rules, If you choose not to do it, or don't feel you need it, that is perfectly fine. Many folks have seen it work, so they test. The Manufacturers created the adjustment because they saw a clear need. If you test enough cameras & Lenses you will find some that need it. But if you have cameras & lenses that perform well out of the box, thats a good thing. But it does not mean that the adjustment is useless.
My experience tells me that it CAN be helpful in some cases, and in my view, Knowing is better than not knowing.

So in an earlier post, I promised to add a chart showing the calibration of my lenses using both my older Canon 5D3 and my current 5D4 body - here it is. Note that all these are with the lens wide open at the recommended testing distance (20-40x the FL). Notice a couple of things. First, every lens required some correction to get the AF perfect, and you can believe that of 5 Canon’s L series lenses (which are used by a large percentage of pros all over the world) are not all bad or out of spec. And secondly, in all except one case, the correction moved in the same direction when moving from the 5D3 to the 5D4. And finally, there are no subjective judgements in these tests - they are all repeatable objective measurements. All cameras are different, all lenses are different, and if you shoot at large apertures and/or small DOFs where the AF accuracy is critical, AF calibration can make a difference if you want or need it spot on.

Hi Gene,

Thanks for taking the time to respond. So let me take your questions one at a time.

1) neither the lens or the camera is defective. I now use the lens on a 5D4 and while the correction is a little different, it’s still in the same direction and even without the correction, the lens is tack sharp. If you don’t correct your lenses, a correction of + or - 7-10 may seem like a lot - it isn’t. I have 8 Canon lenses, and 6 of then are L series and all of them require some correction to be perfect - it varies from 2-13 in either direction. Let me hasten to add that all of them are perfectly acceptable uncorrected, especially if stopped down a stop or two, but they are measurably better when corrected as I often shoot low light, wide open. And I would mention that is what many feel their lenses don’t require correction: (a) they have never seen them sharper, so they have nothing to compare to, and (b) if you typically stop down a couple of stops (and many do as a matter of course), the DOF “hides” the error.

2) yes, I do use the lens at other distances besides 5-15’, but those were the distances where I typically use the lens and I chose to demonstrate that while the correction does change (and here’s the point), it’s always better than no correction.

3) if you’ll notice the shot at the end taken at infinity, you’ll see that the lens still focuses fine, contrary to the assertion (and what I was demonstrating) that even with a substantial correction, it doesn’t prevent the lens from focusing at infinity.

4) you also asked if I mind a substantial defocus at 3’. The answer is that I rarely use a 135 at less than 3’ (I’ll have to look up the nearest focus for this lens) - I have a closer focusing true macro for those shots.

5) actually FoCal also has a seperate consistency test that defocuses and refocuses the lens multiple times and plots the error. In fact, that’s exactly what it does during the calibration - it defocuses and refocuses the lens multiple times at each correction point and all of those points are plotted on the graph, so it’s immediately apparent if a lens is inconsistent.

And that brings me to another point. The typical user that doesn’t calibrate their lenses doesn’t know (a) if their lens is focusing correctly - they have nothing to compare it to (b) when they acquire a new lens, they have no way of knowing if it’s a good copy except a subjective judgement as to whether a give image looks sharp (c) they also don’t know at what apertures their lens is sharpest (often assuming that’s a couple of stops down, which is NOT true of all lenses) (d) they don’t know how much acuity loss there is caused by diffraction at smaller apertures, and (e) they don’t know the repeatability of the AF. I immediately know all these things about all my lenses, not by subjective judgements, but by actual objective measurements. Later I will add a chart of my various lens vs correction and it will be apparent that almost all benefit from some correction. It may only increase the acuity 5-10%, but since I’m often paying $1000 for a lens or more, I want every last bit of sharpness it can deliver including and especially side open.

I come from a precision measurement and QA perspective where we calibrate all our tools because we know that every dimension and assembly has a tolerance, and if you add two complex assemblies together, the tolerances may stack up so they cancel, making everything “perfect” (which VERY rarely happens), but more likely they add to make the tolerance of the entire system worse than the tolerance of each individual part, so we calibrate the entire assembly, which is what lens calibration does. We also know that if your measurement instrument is flawed, or requires a subjective judgement, then it may lead to wrong conclusions. Case in point. Almost every week an OP posts an unsatisfactory image taken with a new lens or camera and wonders what the issue is. Is it AF, is it movement, is it inadequate DOF or SS? Did he get a “bad copy” of the lens? I never have any of those questions, because for less than $100 for ALL my lenses, present and future, I KNOW that I have a good lens or not and that I’m getting 100% of the acuity I paid for. And I don’t have to live with everything being “within factory tolerance”, but not as good as it could be. I don’t have to have my lens “matched” to a specific body, and I don’t have to ship my lenses and cameras both ways to and from the factory subjecting them to shock or damage which can undo the very reason I had them adjusted. Seems like a bargain to me.

Every Manufacturer added the AF fine tune feature to DSLRs because all manufacturered items have tolerances, Cameras & Lenses are no exception. By and large they do a very good job but occasionally the DSLR is at one end of the allowable Tolerance and a given lens may be at the other. In this instance focus accuracy can be improved with AF Fine tuning. Doing the test (which is easy to do manually or with one of the automatic applications) lets you know how your cameras & lenses match up. Ive done it on many cameras and many lenses, both Nikon & Canon on cameras that are used professionally. Most times, I have found adjustment is not needed, but Sometimes it is and in those cases it can help a great deal. It mystifies me why this is a controversial topic?
There are no rules, If you choose not to do it, or don't feel you need it, that is perfectly fine. Many folks have seen it work, so they test. The Manufacturers created the adjustment because they saw a clear need. If you test enough cameras & Lenses you will find some that need it. But if you have cameras & lenses that perform well out of the box, thats a good thing. But it does not mean that the adjustment is useless.
My experience tells me that it CAN be helpful in some cases, and in my view, Knowing is better than not knowing.