imagemeister Loc: mid east Florida

OR, maybe your "test" does not show adequate resolution ...
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mwsilvers Loc: Central New Jersey

I don't like fixing things that aren't broken either. But this is more a case of optimization. Your lenses probably give you very good results and may seem to you to be working optimally. However, in my experience fine tuning lenses that already appear to be sharp can often noticeably increase the sharpness. Whether that is important enough for someone to put in the effort is a personal decision.

Keep in mind that one of the main reasons that fine tuning is often useful is due to normal manufacturing tolerances. The same lens can give slightly different results on different camera bodies. Additionally, multiple copies of a lens may give slightly different results on the same body. That is one of the main reasons a fine tune feature is present in so many camera bodies. Normally, fine tuning is more about adjusting for those manufacturing tolerances rather than fixing lenses with problems.

TriX Loc: Raleigh, NC

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.

(Download)

farwest Loc: Utah

Now whether you can SEE any problem or whether the AF could be better and provide sharper images is a different question, and if you’re happy, then God bless and carry on, but on a DSLR, sharp images in the viewfinder don’t necessarily equate to accurate AF with all lenses.


Your absolutely correct been there done that. Love the discussion as I've had some that are dead on and others that mostly like to back focus. The kicker is if your shooting sports the focus tracking lacks sometimes.

Thomas902 Loc: Washington DC

TriX you are a superb ambassador of the craft... Thank you so much for your dedication and wisdom here...
If only others would document their inferences this site would be a far better place...

Best wishes on your epic journey TriX
I for one am humbled by your perseverance to bring science to the fore here...
Cheers!

chasgroh Loc: Buena Park, CA

15 years of Nikon equipment with much glass and never have done a calibration. That statement just speaks to the fact that nothing has ever looked soft on my monitor...unless, of course, it's my bad handling of said equipment! I'm pretty sure if I detected a problem I'd be on it, but it ain't broke yet so I'm surely not going to "fix" it, lol...

Thomas902 Loc: Washington DC

farwest...your inference on the parameter of a camera's focusing engine (and the lens' ability to pull the glass into focus may in many cases be a limiting factor) is indeed spot on.

I finally gave up on my wonderful AF-S 200-500mm f/5.6 for shooting soccer once I switched to an AF 300mm f/2.8 lens. My "keeper" rate more than tripled! The delightful and cost effective AF-S 200-500mm f/5.6 was great if the player(s) moved parallel to my position, albeit for approaching players the glass was just too slow to move into critical focus... Lesson's learned... experience is a brutal teacher, albeit a rather effective one... lol

Jules Karney Loc: Las Vegas, Nevada

Your time and effort are very much appreciated. Happy New Year.

Kristian Loc: Monrovia, CA

A guy here in LA advertised some Nikkor lenses on FB. Said he was switching his setup to Canon. One was the 50mm f1.8. I was interested in that lens, so I went to see the guy to look at it. He told me straight up that he was selling it cheap because it was never tack sharp. I stuck it on my D810 body and took some pictures of stuff like spoons lined up on the table (we met at a coffee shop, I'm paranoid). I could see that on my body it was back-focusing. I showed him what was happening, and he didn't care. He had no use for it. I gave him $65, took it home and tuned on the Focus Tune rig, and it's perfect. Spot on. Score.

My 28-70 f2.8 came in at different recommended setting at various focal lengths and fstops. If I were to adjust it for one, some of the others would be thrown off by more. I left it alone, and frankly it works well and is my go to lens most of the time.

JIM H Loc: Broad Channel NY

From the Nikon manual "Fine-tune focus for up to 12 lens types. AF tuning is not
recommended in most situations and may interfere with normal
focus; use only when required. With that said I have gone against the advice of Nikon and used FoCal to fine tune some second hand lens. providing better overall focus, and the additional test the program runs, like the aperture sweet spots ,and checking the consistency of focus have transformed a bargain lens into great lens. Or at best comfrim it was not the bargain i thought it would be.

DaveyDitzer Loc: Western PA

Several of you responded to this thread cautioning novices to avoid fine tuning. Having too much GAS and too little experience I tried fine tuning and am not sure it was wise. I would like your collective wisdom on returning all my fine tuning adjustments back to zero and look at a range of photos and then maybe refine my technique with one lens. My bodies are Df(2 of them). I don't think my D5600 allows for fine tuning. My FF lenses are 50mm (1.4D, 1.8G and 2.8 macro), 85mm f1.8D, 105 f2.8D macro. I'll skip the list of zooms for now. Maybe the zooms should be the first ones to reset to zero. My 70-200 f4 AF S required a +18 on one body and a -10 on the other body.
Appreciate your advice.

TriX Loc: Raleigh, NC

All you have to do is turn off AF fine tuning in the menu - one click. Why not shoot a high res test target or a very fine print label at a distance, wide open with it on and off and see which yields the best results -easy test and no harm done if it doesn’t improve your AF/sharpness.

DaveyDitzer Loc: Western PA

Thank you

imagemeister Loc: mid east Florida

Your longest lenses should take priority ....
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MJPerini

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.