polonois Loc: Lancaster County,PA.

My experience at fine tuning lenses has shown me that it works fine with prime lenses less than 200MM. However trying to fine tune a 100-400 zoom lens F4.5 at 400MM is possible but it get less than great results. I watched the videos too and focusing with a F1.4 or 1.8 aperture it works great. Focusing on a target at 50 times the focal length on a 400MM f4.5 is a beast and trying to keep everything square not to mention that at F4.5 the depth of field is so large that most of the scale on the angle part of the bar on the focusing tool is in focus making it extremely hard to see how much your lens is off even pixel picking. If your retired and have all day go for it. If you have a Nikon you might try Dot Tuning it works much better. Try to find a dot tuning video. You'll be glad you did

Jimmy T Loc: Virginia

I think not since my subject's eyes (in keepers) are (almost) always in focus up to 100X.
There is also the fear factor of being without my equipment for long periods of time when I have to send it back to Canon for (re)calibration.
You see, I lack the time, patience, equipment, and training to perform "Fine Tuning" of anything as complicated as a piece of expensive, precision Canon Camera equipment.
I have a lot more to learn about my Canon equipment, Computer processing programs, and my computer.
Great topic though.
Have a Safe and Healthy New Year!
Smile, (With Your Mask On!)
JimmyT Sends

Raynman

My friend and I have identical cameras & lenses (Canon). We calibrated our lenses together on the same day. Results were different for each lens.

Don't forget, Calibration is a combination of the lens AND the camera.

No 2 lenses are the same out of the factory -- quality control is the goal, but not 100% achieved.

No 2 Cameras are the same out of the factory.

Focus is a function of both the lens and the cameras. You can switch cameras with a friend and use your own lenses -- you may find your focus is not the same.

The slightest variation in the position of the mirror will affect the focus.

Recently, I went mirrorless -- best move I ever made. I don't even have to think about calibrating my lenses. What I see is what the sensor sees. I KNOW when it's in focus.

GLSmith Loc: Tampa, Fl

About 7 years ago, I invested in a 400mm F/2.8 new & was dissatisfied with the sharpness. I spent about 6 weeks to 2 months doing all sorts of tests, tried different camera bodies...I contacted an old acquaintance who used to work for Nikon labs and was told to learn to calibrate my lens to the camera body.....which led to a new series of investigations...Long story short, I've bought new equipment & lenses & for the primes (500mm & 600mm), I selected Focal software. . For each lens, I run a total of 7 tests and then average the 7 results. May be a bit of overkill, but as my targets are 1 1/2 to 3 miles away (rockets at launch pads) & in air, the sharpness is paramount. I've also read Steve Perry's article & it seems to be on par with what the software does.

TriX Loc: Raleigh, NC

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.

Thomas902 Loc: Washington DC

Kind of surprised that the no one has mentioned adjusting their Sigma/Tamron Lenses with either the USB Dock/Tap In Console... Both devices have received excellent reviews by knowledgeable "published" photographer "Gurus"

The idea here is that both Sigma and Tamron want to make your experience with their glass as optimal as possible by allowing you to adjust their lenses' focus function over a wide range of focal lengths and focus distances...

I would honestly consider these third party aids if I only had a single camera body... That said the primary issue I have with them is they can only adjust their lens for a single camera body... and while it appears to be very successful by many first hand accounts. However it becomes a rather questionable solution if you want to attach the lens to a second or third etc body. You then have to run the entire process again and the "tuning" is "baked" in to the lenses firmware...

Thus since those who shoot commercially typically arrive on set with at least two bodies thus I'm not able to recommend this Sigma and Tamron solution for commercial shooters... Albeit it could be a stellar adjunct for hobbyist who are far less likely to work with multiple bodies on their endeavors... See the glass is half full if you are a hobbyist!

The good news it can be used to correct Sigma and Tamron high end primes (yes primes can (and often do) change focus precision at varying distances) so kudos to both Sigma and Tamron!

If you might be interested here is a brief Infomercial on the Sigma Dock
https://www.youtube.com/watch?v=n0TqxdZSlaA

Hope this might help or at least be food for thought.
Wishing you all the very best in the New Year ahead...

Cookie223 Loc: New Jersey

I would be very interested in this procedure.

editorsteve

I use my Pentax K3 with a Tamron 18-200 (made for aps-c sensor) that required A LOT of correction...9 on the 10 point scale Pentax allows for each of up to 10 lenses. I corrected at a number of focal lengths and got best results -- near perfect -- around 50. This was by far the biggest correction i have ever had to make on any lens. But I have a bunch of "dumb" old manual lenses (some nearly 50 years old!) that test perfect. Go figure.

mwsilvers Loc: Central New Jersey

Absolutely. if you are happy with what you have, don't change anything. I was also happy with what I had until I saw the improvement I got after fine tuning my lenses, and now I'm even happier. However, fine tuning takes a lot of time, effort, and attention to detail. It's not for everyone.

camerapapi Loc: Miami, Fl.

I contacted Nikon some time ago in regard to lens calibration. I was told not to calibrate a lens if the results I was getting were what I expected. Lenses are calibrated at the factory.
I have never calibrated any of my lenses.

imagemeister Loc: mid east Florida

Yes, I do it - and I sleep better at night. The longer and faster and more expensive your lens, the better reasons you have for doing it ! - or, having it done. And, no, I am not a perfectionist and MY fine tuning probably does not achieve perfection just closer to perfection than not.
.

uhaas2009

I never caliphate and glad I didn’t. I used the nikon 7000 body and certain lenses wouldn’t focus probably so I used just certain lenses. When I got my 810 all lenses focused without any problem. I had to learn that the focus engine on my 7000 was bad.

Markag

Yes. I was close to returning my 80-400 to Nikon until I tuned it through their Z7. Fairly simple procedure.

one_eyed_pete Loc: Colonie NY

I test every lens I add for back or front focus, especially used lenses. So far I haven't found any that needed adjustment. Maybe I've just been lucky? However, I suspect some on here would strope every razor blade out of the box with the belief every blade could benefit from some sharpening. I prefer to spend most of my time trying to improve my skills behind the camera to get the fullest potential from my equipment.

nimbushopper Loc: Tampa, FL

I've never had to do that before, and I don't like fixing things that ain't broke!