mikedent Loc: Florida

OK, thanks- these are great answers!

TriX Loc: Raleigh, NC

I can’t speak for Nikon bodies, but Canon bodies allow 2 focus corrections for zooms.Typically one is used for the wide end, and one for the tele end, but you can use any 2 FLs you like. Canon bodies recognize the lens by type and serial number and implement the proper stored correction, but I can’t speak for how they react to 3rd part lenses.

User ID

IIRC, when I tuned up my Nikons' AF it
offered two FLs [user elected] for every
zoom lens. [D610 and D750]

I've only tuned up for 3 lenses, 2 Nikon
zooms and a Tamron prime. Fortunately
the Tamron is now accurate near to far.
The Nikon lens needed attention but are
now "good enuf".

Don't even bother tuning up shaft drive
AF lenses.

Altho I have a few shaft drive AF lenses
I don't bother tweaking for them. Shaft
driven AF is so sloppy and inconsistent
that they defy tuning up. Simply cannot
get the same AF result to repeat across
several runs. This true even using AF in
live view on an excellent target in good
light. That tells me the shaft drive in the
body and lens isn't even precise enuf to
benefit from matching the lenses to the
analog [SLR] AF system for normal use.

You can check shaft drive lenses against
the "Electronic RF" in a Nikon SLR and
compare focus scale readings. Focusing
via E-RF bypasses the shaft drive, but
the lenses's loose sloppy helicals, that
accommodate the feeble AF motors, are
in themselves a big part of the problem.

Doc Barry Loc: Huntsville, Alabama USA

Hi User ID,
Perhaps I don't understand your first statement about the D750 having two AF tune values for each lens. The D750 manual states there is a single value allowed for each lens and a total of 12 lenses. I am unaware of any Nikon camera offering two values per lens. Canon does for whatever their reason may be. Kindly explain and thanks in advance.

TBerwick Loc: Houston, Texas

Was just now able to return to the post. My D500 will store info on 20 lenses. I noticed that my 28-70 Tamron G2 was really improved after the test. I am planning to do an in depth calibration on the 70-200 G2 & the 150-600 G2 at multiple distances & then locking those readings with the Tap In console. I also believe that 2 telephotos should benefit from more testing and data points. I need some cooler weather for the big lens as the only place I had enough room was my back yard at about 92 F at the time.

I do think the Reikan software is beneficial & takes a lot of the guesswork out of the process. It does become tedious when the lens apparently has some issues the software can't deal with such as extended front or back focusing. It's possible the extremes are camera limitations as it looks like the D500 is limited to +/- 20 micro-adjustments.

abc1234 Loc: Elk Grove Village, Illinois

Reikan FoCal sets the micro-adjustments in the camera so you do not need the Tap In console unless you want to go crazy with all those distances and focal lengths. With my Sigma lenses, the adjustments appear linear.

The numbers on the camera and console probably do not correspond to each other. Let FoCal do all the work and forget about the console.

Only 92? I thought this was supposed to be hot time of year down your way.

Doc Barry Loc: Huntsville, Alabama USA

Hi abc123,
I believe you are mistaken. FoCal sets the micro adjustment for each focal length and distance. You record these values, 18 for the Tamron 150-600 G2. These are input manually into the TAP-IN Console program which then computes the compensation coefficients that are loaded into the G2 when the TAP-IN is mounted on the G2. The camera micro adjustment is set to zero.

It takes time to do the job right, but it is worth it.

abc1234 Loc: Elk Grove Village, Illinois

Hi Doc,

Canon and Sigma do not do it that way. I do not know about Nikon and Tamron and leave you to find out for yourself. Reikan confirmed to me that with my gear, the numbers do not agree and not to use the Dock.

I agree with you about the value of the testing. However, by time I set up the equipment and all the other housekeeping, I figure on at least thirty minutes per lens. The actual capture time is the fastest part.

Doc Barry Loc: Huntsville, Alabama USA

Hi abc1234,
Yes, I was referring to Nikon and Tamron.

User ID

Dreadful sorry ..... altho I did state it as "IIRC" !

I use both Nikon and Canon, and given that AF
micro-tweaking is not a routine daily use feature,
I must've been thinking of my Canons. My bad :-(

When it comes to a "set-it-and-forget-it" chore,
I'm apparently especially good at the "forget it" !

But the point of my mentioning it was NOT to
recommend the Nikon brand as more thoroughly
addressing the problem. I was only pointing out
that SLR AF inaccuracy is a very real issue, such
that at least one maker has seen fit to provide a
more elaborate approach ... which implies that
if SLRs continue evolving, we may see FAR more
elaborate fixes. And that ... to me ... puts SLRs
on equal footing with the piston engine, IOW a
very highly evolved, adapted, and entrenched
technology that lingers on despite its obvious ...
even glaring ... shortcomings. So again, sorry if
I said "Toyota" when I should've said "BMW", but
the essence of the message is not in the brand.

Doc Barry Loc: Huntsville, Alabama USA

Hi User ID,
Thanks. That explains it. I like your piston engine analogy.

Although I had calibrated my 150-600 G2 lens and it appears to work well, I used the older FoCal to do so. My curiosity made me ponder a bit about the procedure I used so I contracted both Tamron and Reikan. Tamron said that there is not a specific or definite relationship between the AF adjust values and the value that should be input into the TAP-IN program to upload to the lens. Reikan told me that they and other of their customers found the values appear to be about one-to-one between the camera and the lens. This is what I observed also with my Nikon D810. I plan to soon to do a very carefully test with the latest version of FoCal Pro to determine the ratio of the Nikon to Tamron values for both my D810 and D7000 bodies. Reikan told me that the Sigma lenses with their docking device have a ratio of values that are varied and significant, e,g,. > 2:1. I don't have any Sigma lenses and only the one Tamron lens. Once I have completed my testing, I will start a new post to report what I learned.

I don't have a Canon body, but if I did I too could be easily confused.
Best regards,
Doc Barry