Simple auto-focus calibration for DSLRs with adjustable settings.

Blade Canyon

Senior Member
I saw this in another Nikon forum, and it worked so well it's worth sharing. I have the Focal software, and it's slow to use and a hassle to set up. For this method, you don't even need to take any pictures.

For beginners, high-end Nikon bodies have a feature in the set-up menu called "AF fine tune." You can make tiny AF adjustments to make each lens sharpest right where you are focusing, and the camera body remembers this adjustment for each lens.

The simple idea here is to use Live View zoomed in to achieve perfect focus, then use the viewfinder's focus indicators to know how to adjust.

With camera on tripod, do these steps in order.

1. Set camera to manual focus.

2. Turn on Live View and zoom it all the way in (using the + button) on your chosen focus chart or other busy subject. Manually focus to perfection. Live View shows you exactly what's on the sensor, so if it's in focus in Live View, it should be in focus in your photographs.

3. Turn off Live View and LOOK THROUGH THE VIEWFINDER, and depress the shutter button slightly so the focus indicators turn on (bottom left of the info bar). Again, you should still be in Manual Focus mode, so touching the shutter button should NOT cause the lens to refocus.

4A. In the viewfinder, IF the round green circle appears while putting pressure on the shutter button, your auto focus system agrees that your manual focus was correct. Lens is calibrated. Stop here and try another lens.

4B. But, looking through the viewfinder with the shutter button partially depressed, if the round green circle does not appear, it means the auto-focus system in the camera does not agree that the image is in focus, so you have to make adjustments to the calibration WITHOUT CHANGING THE POSITION OF THE CAMERA OR THE FOCUS YOU ALREADY SET MANUALLY. In other words, you are teaching the camera body that the existing setting is the correct focus.

5. If the arrow points to the right, the camera's AF system believes you are back focusing, so go to AF Fine Tune in the menu. Make sure the AF Fine Tune feature is set to ON. Set the number value to -5. SAVE IT. Look through the viewfinder again and see if the focus indicator has changed. If the green circle now appears, your lens is calibrated. If the arrow still points to the right, change to -10. If the RIGHT arrow appears at this point, your initial change was too much, so reduce it to -3, for example. Keep making adjustments until you get the round green circle in the viewfinder. You would do the exact opposite if the initial reading of the focus indicator pointed to the left.

That's it. Remember to save your settings. Test the settings by putting the camera back in AF mode, and shooting down a ruler or along a bookshelf to see if the focus point you select is the same one that is sharpest in your photos.
 
Last edited:

Blade Canyon

Senior Member
Blade... How far should the camera be away from the target?

Good question. Reikan says somewhere between 25-50 times the focal length of the lens. That means for a 200mm lens, you would have to be a minimum of 16 feet away. I would say do it at whatever distance you normally use each lens. The important thing is to make sure you are close enough to see the extremely fine focus on whatever target image you use. For my target, I generally put up a book with a busy front cover or a back cover that is covered in small quotations.

But you can download Reikan's main target for free, here:

http://s449182328.websitehome.co.uk/focal/dl//Docs/Targets/r2/FoCal_Target_5r2ns.pdf
 

Bob Rules

Senior Member
I ended up doing this test on my tamron 70 -200. I tested at 70mm, 140mm and 200mm. At 70mm, my adjustment was +5. Is that good or bad? When I moved to 140 and 200, I did not need to make any further adjustments. The focus stayed locked in.

I also learned that my Targus tripod was a piece of crap. I never understood what everyone meant by sturdy until my rig kept drifting off the target. Needless to say, I will be in the market for a new tripod. I think I have my eye on the mefoto globetrotter.
 
Last edited:

J-see

Senior Member
I ended up doing this test on my tamron 70 -200. I tested at 70mm, 140mm and 200mm. At 70mm, my adjustment was +5. Is that good or bad? When I moved to 140 and 200, I did not need to make any further adjustments. The focus stayed locked in.

I also learned that my Targus tripod was a piece of crap. I never understood what everyone meant by sturdy until my rig kept drifting off the target. Needless to say, I will be in the market for a new tripod. I think I have my eye on the mefoto globetrotter.

It doesn't matter much how high the adjustment is as long as your lens will still focus at infinity. If you're closing in too much at +20 you might run into problems and better have the lens adjusted at the manufacturer.

You can only adjust it at one focal length. The AF fine-tune stores only one setting for one lens. Just make sure you got all dots since a lens can give a focus lock for a range of settings. Of that range you have to pick the middle.
 

10 Gauge

Senior Member
This is an interesting way to adjust the AF fine tune. Thank you for this [MENTION=15302]Blade Canyon[/MENTION], I'm going to give this a shot with my lenses over the weekend and see what results we come up with. Cheers.
 
I have tried this but used a LCD screen magnifier when viewing in live view. If you have a lens with a focus ring that moves when it focuses then its easy to see if it moves when you hit the shutter button in AF ..If the lens has OS its best to turn the OS off and listen to see if the focus motor makes a noise when you swop from LV to AF
Good idea whoever had it.
The Tokina 24-200 needed +20 and more so I removed the mount and put in in the lathe and took 3 thou off the rear of the mount...all the connection fingers fell out requiring a tweezer rebuild !!! All fine now ..1 thou per 10 if you go this route.
 
Last edited:

Elliot87

Senior Member
Just FYI, this person has an awesome video for what he has coined the "Dot Tune" method of AF Fine Tune adjusting, which is the same method as the OP has suggested.

https://www.youtube.com/watch?v=7zE50jCUPhM

This description box for this video suggests not setting the camera or lens to manual focus on Nikon bodies for the following reason and suggests setting back button focus instead.

"*** Important Update for Nikon Owners ***
After making this video it was discovered that on Nikon bodies the viewfinder focus confirmation range increases dramatically when the body or lens is changed from Autofocus (AF) to Manual Focus (MF). I believe this is becase Nikon wanted to make manual focusing easier and faster by increasing the range of focus that provides a confirmation. However for DotTune this behavior is undesirable because it increases the range of tune values, sometimes beyond the limits of the +20/-20 AF tune scale. Luckily there is an easy workaround, which I strongly advise Nikon owners to use:

For step 3, do not set your NIkon body or lens to MF. Instead, configure your body for "back-button" focusing. Back-button focusing means that the Autofocus will not be engaged by a half-press of the shutter, which will allow you to perform steps 4 and 5 while leaving the body+lens still set to AF."
 
perhaps I did this back to front but I manually focused in LV using the magnifier on the LCD then engaged the AF and looked if it moved...????
 

10 Gauge

Senior Member
This description box for this video suggests not setting the camera or lens to manual focus on Nikon bodies for the following reason and suggests setting back button focus instead.

"*** Important Update for Nikon Owners ***
After making this video it was discovered that on Nikon bodies the viewfinder focus confirmation range increases dramatically when the body or lens is changed from Autofocus (AF) to Manual Focus (MF). I believe this is becase Nikon wanted to make manual focusing easier and faster by increasing the range of focus that provides a confirmation. However for DotTune this behavior is undesirable because it increases the range of tune values, sometimes beyond the limits of the +20/-20 AF tune scale. Luckily there is an easy workaround, which I strongly advise Nikon owners to use:

For step 3, do not set your NIkon body or lens to MF. Instead, configure your body for "back-button" focusing. Back-button focusing means that the Autofocus will not be engaged by a half-press of the shutter, which will allow you to perform steps 4 and 5 while leaving the body+lens still set to AF."

Great now I need to retune all of my lenses. Thanks for pointing that out, completely missed it!!!
 

Camera Fun

Senior Member
Great now I need to retune all of my lenses. Thanks for pointing that out, completely missed it!!!

Have you retuned your lenses yet? If you have, was there much difference after using the back-button focus?
 

Paganman2

Senior Member
I tried the dot focus adjustment, and when i got a clear up + and down - limits where the dot was still and on without the brackets even part flashing, this gave me a range of about 11 steps, so i just split this and had 5 clear steps either side before being slightly out.
I tried it after and seems spot on.

P.
 

Bourbon Neat

Senior Member
Yeah, I have not seen this information until just now after seeing Elliot's post. I went through all lenses and was mystified how I could ruin the procedure on all of them. Was not at all pleased with the results and went the Reikan FoCal route. Much better now.

For anyone wondering, FoCal has the D7200 included now too.

This description box for this video suggests not setting the camera or lens to manual focus on Nikon bodies for the following reason and suggests setting back button focus instead.
 
Top