AF fine tune - LensAlign, DotTune, or other methods?

donaldejose

My zero cost methods have been 1. to place a yardstick (or ruler) propped up on one end on a table and put a sticky or clam on a number in the middle. Focus on the sticky or clamp and the closer and further hash marks on the yardstick tell me if the lens is front focusing or back focusing. Adjust, shoot again. Adjust again. Shoot again until satisfied. 2. I have also printed a set of 5 capital Is in various font sizes on a sheet of typing paper to create a test pattern, taped the paper to a wall, put the camera on a tripod at about the distance I would expect to be from the subject using that lens, shot the test pattern and adjusted the lens until the smallest capital Is were sharp.

spraynpray

I just throw a yardstick on the table and put the camera on a tripod 30 degrees above it and then choose a point to focus on. I also test it against live view and manual focus to see if live view aligns with auto-focus and to see if I can beat the sharpness with manual focus.

I'm going to give a version of PitchBlack's idea a go to see if it is easier to get alignment that way.

Golf007sd

...if you really want it adjusted properly, get your moneys worth, and have a Nikon service Center do it right. Here in Denmark it is a free service with any pro camera and lens combination. That way you get it fine tuned for your combination, and they actually AF fine tune the zooms for several settings. My 80-400mm I believe have 6 points. No way you can adjust for that in any way manually.

+1

henrik1963

I test my lenses the same way @PitchBlack does (more og less).

Aiming for an eye - even with the 2.8 zooms - will give you a clear indication wether the lens is off or not. You can clearly see the difference in sharpness between the eyeball and nose/ear. Moving closer you can see the difference in sharpness between two eyes even when the head is angled ever so slightly.

Zoomes being sharp in one end and not sharp in the other is a different problem - they need to go back to Nikon for repair.

At F1.4 at close range you know if the lens is off.

Photobug

http://youtu.be/SpiJ9qX_-Ds

The web link does not work...please try again. Thanks.

Ironheart

Try this:

Photobug

Try this:

Thanks @Ironheart...that link worked fine.

rmp

Hi, Great thread .... Thanks one and all. The information, suggestions, links were all helpful. I cannot believe I actually read an entire thread.

I still have one question. If I send a lens/camera combination to Nikon and ask them to "calibrate" the auto-focus for the pair, will they adjust the lens and the camera or will they just change the fine tuning numbers?

Or stated another way, is it worth asking Nikon to "calibrate" the lens/camera pair so the fine tuning setting is zero?

PB_PM

If the camera and lenses are all under warranty it might be worth while, otherwise it's a somewhat costly affair.

Ironheart

Everything should come back zero from Nikon.

Hammie

So, I used Reikan FoCal to assist in the calibration of my lenses.

I have three zooms (10-24mm DX, 24-70, and 70-200) and decided to calibrate them this weekend.

My 10-24mm ranged from +2 to +4 throughout the various zoom ranges. My 70-200mm ranged from -1 to +4. Both of these grouped relatively well, IMO.

Now, my pride and joy, the 24-70. At 24mm, it calibrated at +18. At 28 and 35mm, it calibrated at +16. At 50 and 70mm, it calibrated at 0. I ran the test three times and the results were identical. I use the approx. 50x focal length for my distance from the target and rounded to the nearest 1/4 foot.

Any thoughts? Do you think the lens is out of whack and need a Nikon service? Anyone else ever hear of or get results like this.

The documentation out on the Internet is mixed. Some places/people say the average. Others say the Median. And then others say to use the calibration at the most used focal length. And finally, the last group say to calibrate to the longest length.

Grrrr.... Why do I get so wrapped around the axle when it comes to these things? I feel it is my engineering side where I need an exact and not an approximate.

Msmoto

Gosh, I did an AF Fine Tune on my 400mm f/2.8 at night in a football stadium. Just shot across the stadium at a fixed target, then captured images at +5, -5, evaluated in camera, more adjustments and finally in about five minutes had the AF spot on.

But, much easier in a set up .....like in someone's private studio/office... )

kenadams

Oh!! I forgot! One of the great things about shooting at computer screens is that they tend to induce chromatic aberrations even in great lenses... so the place where the magenta turns to green is the point of perfect focus. It works really well.

Not sure the lens is at fault here. It could be. However, what is a fact is that text on a regular computer screen using an OS designed after the stone age uses ClearType technology to produce clean and smooth text. This takes advantage of all newer screen layouts which actually use subpixels to display a single pixel - that means, if you look closely, you'll see three vertical bars of magenta, yellow and green that make up one pixel. So to create an antialiased, smooth character that is not strictly horizontal or vertical, on the edges you'll see color fringing if you look at it with a loupe. It's a super interesting process that (ab)uses the way our eyes perceive color and color intensities to make a font of color "black" appear without jagged edges - by using color and various runs through low-pass filtering around the character stems. That way, a lower case "L" that is using a font size less than one full pixel wide will be put together by two adjacent pixels, one mostly purple/red (left side), the other mostly blue/greenish (right side). Looked at from a typical eye to screen distance, it will appear as thin but black.

Uhm, yeah.

And now for something completely different.

4thebirds

However, if you really want it adjusted properly, get your moneys worth, and have a Nikon service Center do it right. Here in Denmark it is a free service with any pro camera and lens combination. That way you get it fine tuned for your combination, and they actually AF fine tune the zooms for several settings. My 80-400mm I believe have 6 points. No way you can adjust for that in any way manually.

I've read about other people having their gear tuned/adjusted by Nikon. So I called Nikon here in the USA to inquire about the cost. First of all I had to just call the 800 number and the Nikon representative didn't understand me. After she finally understood that this was not a repair, I was finally told was that there are 2 levels of service for non-repairs: (1) Clean Only and (2) Clean & Adjust. The latter option is what you choose to have your lens + camera custom calibrated/adjusted. For that service, each item serviced has a separate cost range. After having them look up the cost ranges for my gear, the LOW cost estimate to have my camera, 500mm lens and 1 teleconverter adjusted is over $500 (possibly quite a bit more), and that doesn't include shipping/insurance costs.

Although I like the idea of having my gear professionally serviced and custom-tuned, I'm not sure I will ever do it unless I become unsatisfied with AF fine tuning, or unless someone gives me an easier way to go about it. It seems the Nikon service in Denmark and other countries is better than here in the USA... I am an amateur, so I am not a member of "Nikon Professional Services." Also my main camera body is the D7100, not considered part of their "pro" line.

Dave

HigginsR

I’m trying to use Dot Tune to fine tune my Nikon 105mm Macro lens. I’m getting a solid dot at -17 thru -20! I’ve tried it at approximately 17 feet and also at the minimum focus distance, not sure what distance to use on a macro lens. Does anyone have any suggestions on testing this lens?

Thanks – Rick

Ironheart

That is completely normal. The PDAF in the body is not as accurate as the Live-View, so just pick the middle value -18 or -19 in your case. You calibrate any lens where you use it the most. If you use it near and far, you either have to compromise, reset the AF fine-tune value, or send it to Nikon for a factory adjustment.

Pistnbroke

For long 400-600mm I have a statue in the garden at about 60 ft and I put a headdress of feathers on it with an elastic band and focus on that then go from -20 to +20 in 5s eventually tuning in on the best ..use flash to remove any movement. for long lenses even + or -1 makes a difference

BabaGanoush

HigginsR said:

I’m trying to use Dot Tune to fine tune my Nikon 105mm Macro lens. I’m getting a solid dot at -17 thru -20! I’ve tried it at approximately 17 feet and also at the minimum focus distance, not sure what distance to use on a macro lens. Does anyone have any suggestions on testing this lens?

Thanks – Rick

Be aware the Dot-Tune test does not work for all lenses. It may/should "work" for your lens, but it fails for my 70-200mm f/2.8 as well as my 80-400mm. For both those lenses, especially at the long end, Dot-Tune tuning tests always yield a micro-adjustment value somewhere in the vicinity of +20, but the images I get if I choose such a large adjustment value are out of focus. In a private email, Thom Hogan once told me he's experienced a similar issue with Dot-Tune for his 80-400mm. These days when I test a new lens I just take a series of pictures of specific targets at different micro-adjustment values and pick the value that yields the sharpest image when I examine the entire set by eye in Lightroom. I like to use a utility (electric power) pole for my target because I shoot lots of landscapes, but you would probably use something different for macro work.

Pistnbroke

I would set up a typical for you static macro shot and go =20 to +20 and see where its best when viewed 100% on your computer

spraynpray

Here's a weird thing: I am finding Sigma are selling their Art lenses without getting them even close to right on AF fine tune. Whether that is a marketing ploy to sell docks I cannot say, but when I phoned them to moan about my 24-35 f2's terrible focus out of the box, they immediately told me to buy a dock! Damn cheek really, and I told them as much.

That said, I found that arranging a tape measure at 45% and checking the focus alignment showed it to be so far out that going to +20 only got it half way right (plain to see). I then used Focal to align it and that gave me a result of +10 and greatly improved focus! Although the focus is much better now, I will send it in for them to complete the production process on it instead of passing it off to customers.

YMMV but the above is my experience on 35, 50 and 24-35 Art lenses. 3 for 3 on different bodies can't be ignored.

Ironheart

Get the dock...

spraynpray

Hey @Ironheart: How about they sell the lenses in kit form and I screw them together too...

Somewhat unrelated, but my mate just 'Whatsapp'd' me from Barbados to say his 18-35 f1.8 just broke for the third time (different fault). What's happening Sigma?

MegapixelSchnitzel

spraynpray said:

@Adamz: Pretty soon though all those $$ add up to $$$$$$ - shouldn't we expect cameras and lenses from the same manufacturer to work correctly?

Thank you: my sentiments exactly.

TriShooter

I use Reikan FoCal Pro and love it because it works on automatic instead of manually on my D3S cameras with lenses up to 600mm and with and without teleconverters. I also use it on a D800 and a D7200 but manually which means shoot/wait for focus/exposure taken/ and then repeating the process. I love this program and can vouch for its accuracy using the above cameras providing you shoot at the distances Reikan Focal recommends in their manual.

reikan.co.uk/focalweb/index.php/why/camera-compatibility/

On zoom lenses, most people do their fine tuning at the long end of the zoom range because there is more depth of field in the short or wider angle end of a zoom.

Killerbob

In the past I have wholeheartedly supported Reikan Focal Pro, and the functionality is indeed pretty good.

HOWEVER, lately they have changed their licensing setup, and you are NOT buying the software and updates, you are only buying the software in its current version. Then when the software is updated you have to buy an update license, and as it is necessary to update to support new camera models, it is not only expensive when you buy it, but very expensive in the long run - especially if you like to keep your cameras current.

I have discussed this with the company, and though they had sold the original version without these limitations, they have since then introduced them, and they will NOT honor any grandfather clause.

I find this type of business ethics despicable, and I can no longer support FoCal.