Doc Barry Loc: Huntsville, Alabama USA

Actually what is stated in the technical note is as follows:
"If you find that certain lenses do not produce the desired results with autofocus, you can fine-tune autofocus for each lens using the AF fine‐tune option in the setup menu. AF tuning can also be used to offset focus from its normal position for a deliberate defocus effect. Note that AF tuning is not normally required and may interfere with normal focus; use only when necessary. Check focus before making any adjustments using Saved value or Default option.

Note that fine-tuning applies only with phase-detection AF (viewfinder AF) and is not available during live view."

I fear that you don't understand what the tech note is stating. Yes, you do the AF tuning at a single distance and focal length (for a zoom), but it should then be correct for all focal lengths and distances. This is because Nikon has carefully designed into its lenses a compensation/correction for the zoom and focus mechanism so that (ideally) once it is AF tuned, it should work correctly for all distances and focal lengths. The guidance given in the tech note is suggesting a distance where the error in the compensation equation is minimal. Try other distances and focal lengths once you AF tune the lens and you should see it works fine. Set it for a different distance and focal length and compare photographs of a target with and without the AF tune. All of my Nikon pro-glass lenses required a slight correction, except two. One was spot on and the other I sent to Nikon Repair to have recalibrated. They confirmed it was off and they fixed it just fine. It too need a +2 AF tune correction when I receive it back, but was now great over the range of distances and focal lengths.

And of course the AF tune doesn't work with Live View as its states in the tech note since the mirror is up and it is behaving like a "mirrorless" camera.

Doc Barry Loc: Huntsville, Alabama USA

Thanks for sharing those beautiful photographs of the birds.

Reconvic Loc: clermont Fl

We all have good experiences with the lens that we're using. It seems the only photographer here is Gene59 that has used them all EXTENSIVELY and for what little extra money I'm upgrading to the G2 (when it's ok with Sally)

Reconvic Loc: clermont Fl

Gene51

pmackd Loc: Alameda CA

My 200 -500 is very sharp at 500mm f 5.6 and did not require AF Fine tune. It is still sharper at f8. With the Nikon 1.4x III TC (f8 net) it may be a little less sharp but that can be greatly improved by stopping down to f10 or f11, a practical alternative only for static subjects. That means the lens is effectively a 700mm for static subjects in good light and 1050mm FX equivalent on a DX camera. With or without the TC I am able to hand hold the 200-500 safely for only a few shots at a time without risking my left elbow tendons (once you damage them they will never be the same, so be careful)

doctp Loc: ny

What is the “Ultimate” setup for the bird photographer?
I have the Nikon D 500 with the $6000.00 Nikon 200-400 mm lense, so when used in dx format, it is 300-600mm
Are there sharper, faster telephoto made by Nikon or any other great companies?
Photos will be made on a Epson P 600 printer with Epson ink and paper.
Max. Size will be 11X14, any special Epson paper?
Please suggest a photo lab that does the best professional work that you known.
I only save 10-20 images a year and I would want them to be wall hangers.
Other photos printed on my Epson will be great but placed in an album, just not worthy of a “Pro Lab”
Last question promise:
Should I switch from Dx to Lx?
Is there much visible difference in 11X14?
Ty so much for being patient with my novice questions!
Tom

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

Fine tuning is only good for one distance. Many agree with me, including David Busch. I quote him here on page 164 on his book titled "Nikon D850". "Unfortunately, it's only possible to calibrate a lens for a single focusing distance". Now you show me where specifically you got your information.
And by the way, David states this in every book he has written on Nikon AF camera's.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Actually, there is no voodoo in their lens and camera tech, just logical, strong design.

I had a camera, a D800 purchased as a Nikon refurb. Assuming it was fine because it was "gone over" by Nikon's techs as part of the refurbish, I just took it along with my 600mmF4 and a couple of other lenses to an air show. The images I shot with the other camera where about 95% in focus. The refurb gave me about 20%. Midway through the day, I had switched up bodies on the big lens, so I was fairly certain that the problem was the body.

When back at home I started testing lenses, using AF Fine Tune to try and correct the problem and nothing worked. I then tried other lenses, and all had a problem.

I brought the lens to Nikon in Melville and started the process. It took 3 trips to Nikon, and refusing to have the 600 adjusted, which was one of their solutions. I told them that was ridiculous because it was working just fine with my other bodies.

When I went to pick it up the last time, it was perfect. I had other lenses in the car just to confirm what I had suspected - a body-based focusing issue - and all the lenses were fine.

So I went back inside to the tech desk and asked to speak to the person who fixed it, just to find out what he had done, since the "adjusted communication parameters" description on the repair bill was a little vague. This is when I had a great discussion with the tech, and asked him about AF Fine Tune. He confirmed everything I knew about it, and how it was not a good solution except for certain situations. These are the key takeaways from the conversation.

1) AF fine tune assumes the lens is within spec. Note that AF tuning is not normally required and may interfere with normal focus; use only when necessary.

2) Lens focus issues are rarely linear in nature - a front focus problem may exist at 10 ft, but not be an issue at 30 ft, and it could have a back focus issue at 60 ft. They can be made more linear by a tech.

3) The user accessible fine tune adjustment is in fact a focus offset adjustment, affecting all focus. AF tuning also can be used to offset focus from its normal position for a deliberate defocus effect

4) Fine tune is done at just one focus distance. If you have a zoom lens, or tend to use your lens at a wide range of distances, it will only be good for that one distance. in #2, if you adjust for a front focus problem
at 10 ft, you will have a back focus problem at 30 ft and focus at 60 ft will be even worse.

5) Further down in the tech bulletin it states You may have difficulty focusing at infinity or at the minimum focus distance while fine-tuning is in effect and Lenses are listed by focus distance and maximum aperture, and can also be assigned an identifier as described below. since you can adjust focus on a lens to be optimal at close distance and similarly optimized for another distance.

So, if your lens is not focusing well, testing the lens at different distances first will reveal if your issue is lens-based. My experience is that lenses are more often not linear at all, so adjusting for one distance and one focal length if using a zoom is a completely inadequate solution to a focus issue. I have a dozen lenses, and 4 bodies. There is no way I am going to waste time with this nonsense. When I get a new body or lens I test it - if something is awry, it goes in for repair. Nikon, Sigma and Tamron can adjust a lens to make it linear in focus performance - the Tamron TapIn console and the Sigma Dock is a user-accessible solution to "fixing" focus issues in their lenses. NIkon's adjustments are either internal or software based, an those tools are not available. The user accessible lens adjusting tools on zooms offer 4 distances for adjustment, and at 4 different focal lengths. Once the lens is deemed to be linear, Nikon has mechanical and software-based calibration tools to perform focus adjustment in the body.

6) AF sensor mapping could be the culprit, or just a contributor. If the viewfinder is showing focus acquisition, but it is still out of focus, the sensor may not be seeing what the little box is showing in the viewfinder.

AF problems are seldom as simple as can be addressed by offsetting the focus - aka AF Fine Tune. However, ensuring that the gear is within spec, so that if something is off, it can be easily identified and addressed is a much better permanent solution. AF Fine Tune works best if the lens is known to be within spec. If the lens has an issue, then AF Fine Tune will not be a good solution.

Bottom line, make sure everything is within spec.

So, in the interest of fear of not understanding stuff, I offer the following:

You state "it should then be correct for all focal lengths and distances. This is because Nikon has carefully designed into its lenses a compensation/correction for the zoom and focus mechanism so that (ideally) once it is AF tuned, it should work correctly for all distances and focal lengths" - you'll need to provide your source for that. The bulletin certainly doesn't support it.

"Try other distances and focal lengths once you AF tune the lens and you should see it works fine." I have, it hasn't. Which is why I have so little use for the feature.

"It too need a +2 AF tune correction when I receive it back, but was now great over the range of distances and focal lengths." I suggest that if you test the lens rigorously, you'll discover that an adjustment of +2 is so small that it is within the standard deviation. If you take 20 shots of the same target, deliberately defocusing and letting the camera focus, you'll find that there will be some that are right on, others that will be off by up to ±2 units. That is normal, and it does not mean the AF has a problem.

The reason AF fine tune doesn't work when you are using Live View is that Live View uses CDAF - Contrast Detect Auto Focus that examines/evaulates contrast directly at the sensor and adjusts accordingly. PDAF, uses the two, tiny semi-transparent "windows" in the mirror to detect any phase differences between them, and adjusts accordingly.

Here are a couple of articles that are a good reference:

http://www.dslrbodies.com/lenses/lens-articles/lens-technique/tracking-down-autofocus.html

http://www.dslrbodies.com/cameras/camera-blogs/the-d5d500-blog/the-af-fine-tune-itch.html

https://photographylife.com/how-to-calibrate-lenses

Thanks for trying to help me better understand how AF Fine Tuning works.

RV Loc: Chicago

I would check out used on KEH, Adorama, or B&H. Usually better prices than on the Nikon Website and just as reliable.

DaveyDitzer Loc: Western PA

To Doc Berry's explanation of the focus features and settings that he learned from Nikon.
Question: In your view, if I have "diddled" with AF fine tuning for any of my cameras and lenses, would you recommend resetting these to zero and leave well enough alone?
Thank you for your very educational post.

artpulis

By far my favorite lens, but I never have it on without my monopod - not to steady but as a rest.

Doc Barry Loc: Huntsville, Alabama USA

Hi Davey,
You are likely better off just setting the AF fine tuning to zero if you just "diddled" with the settings. When determining what AF tuning is appropriate, you need to have the camera on a tripod and trigger it remotely. Also you need an appropriate target to use such as the Spyder LensCal, LensAlighn MkII, or Reikan FoCal Pro. I like the FoCal best. I typically run it five times to assure myself that the value computed for the AF tune is solid. As someone else mentioned, if the value is not stable, then there is another problem to address such as the lens needs to be serviced or the camera body. The camera systems we have today are technologically sophisticated and there are many ways they can foul up in operation. Frankly, unless one has a good setup and calibration tools available, just leaving it alone is the best idea as you suggested. Tweaking or diddling the AF fine tune by guessing by eye isn't wise IMHO.
Best regards,
Doc Barry

DaveyDitzer Loc: Western PA

Doc,
Thank you. I do have a focus target, but probably lack the technical skill or visual acuity. I appreciate your advice.

DaveyDitzer Loc: Western PA

Doc,
PS I did use a tripod and a 10second shutter delay.

Doc Barry Loc: Huntsville, Alabama USA

Good show Davey. If you are doing it manually (i.e., not under computer control such as FoCal does), you need with your target a tilted scale to aid your eyes in determining if there is frontward or backwards focusing error. See LENSCAL below. You can make your own using a ruler or yard stick, but be sure your camera lens axis is orthogonal to the target. As you can see, my iPhone is forward focusing a bit although it was focused on the target.