Tips needed on AF fine tune

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gustafson

Senior Member
I've been using a 200 f/4 Q.C mounted on a TC-16A as a poor man's telephoto for birds, but ended up with poorly focused shots on my last outing. I posted about this a few days ago and was advised that there seemed to be a front-focusing issue (http://nikonites.com/telephoto/36738-advice-needed-sharp-bird-shots.html#axzz4CKuipBCq). I checked the focus points and they seemed to be on the subject, so I figured that the setup could have a front focus issue (not noticeable for close-in subjects, but apparent for subjects 25 ft or beyond).

Yesterday, I looked into AF Fine Tune, and got some interesting findings. My subject was a cereal box with a ruler at 45 degrees adjacent to it, about 20 feet away. At this distance, however, AF seemed to be accurate as far as I could tell. Just for grins, I dialed in an adjustment of -20, and didn't see much of a change in the photo. Then I dialed in +20, and again, nothing seemed to have changed. This surprised me a little. Wondering if there's an explanation of this, and more importantly, if there's a preferred way to diagnose a front focus / back focus issue and correct it with AF Fine Tune. Thanks!
 
D

Don Kuykendall_RIP

RIP :(
All distances need to be at 50 times the focal length. With the D7100 you need to be sure to factor in the effective focal distance for the DX factor and for the TC. Also you will need to set the Fine tune twice at both with and without the TC.

Fine tuning a lens/camera is not an easy thing to do sometimes and you can't do it without transferring the shots to a computer.. Don't think that you can do it by looking in the back screen of your camera. Don't use a cereal box. Find a good target online. Stark black and white so that the the auto focus is dead on every time.

If you could not tell the difference in -20 and +20 then you did something wrong. i have done this several times on several cameras including my D7100 with about 6 or 7 different lenses. It does make a difference.
 
Danno

Danno

Senior Member
Don Kuykendall said:
All distances need to be at 50 times the focal length. With the D7100 you need to be sure to factor in the effective focal distance for the DX factor and for the TC. Also you will need to set the Fine tune twice at both with and without the TC.

Fine tuning a lens/camera is not an easy thing to do sometimes and you can't do it without transferring the shots to a computer.. Don't think that you can do it by looking in the back screen of your camera. Don't use a cereal box. Find a good target online. Stark black and white so that the the auto focus is dead on every time.

If you could not tell the difference in -20 and +20 then you did something wrong. i have done this several times on several cameras including my D7100 with about 6 or 7 different lenses. It does make a difference.
Click to expand...


Don what do you use for tuning your lenses?
 
C

Camera Fun

Senior Member
I always struggled when using any type of angled system (even if it had a flat target for focusing on). Probably due to not getting the camera properly aligned with the target. I've done better with the dot tune method but still struggled with variable results but I think that was due to too much camera movement from all the button pushing. Recently I tried the dot tune again with my 24-70 but took extra time to ensure properly alignment between the D7000 and the target; used 50 x focal length of 70mm; and was very aware of not moving the camera. I ran the test 10 times and eliminated 4 results that were way off from the others; which gave me 6 results ranging from -5 to -7.5. Then with the camera still on the tripod, I photographed the target using settings of -4 to -8. When I viewed them on the computer, the -6 setting was the sharpest.
 
Danno

Danno

Senior Member
Don Kuykendall said:
I am old and my eye site is not that good so I had a lot of problems seeing the difference in +3 and 0 in the ruler so I went with a software/computer based Fine Tuning system.

https://www.reikan.co.uk/focalweb/

It is not free but I really like it. It has made a major difference in my cameras. It runs a little over $100 for the pro version.
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Thank you Don, I have to admit I struggle with those type things as well. I remembered you mentioning it before, but I could not find it back. I will be looking into it today. Thanks.
 
J

Johan65ZA

Senior Member
Don Kuykendall said:
I am old and my eye site is not that good so I had a lot of problems seeing the difference in +3 and 0 in the ruler so I went with a software/computer based Fine Tuning system.

https://www.reikan.co.uk/focalweb/

It is not free but I really like it. It has made a major difference in my cameras. It runs a little over $100 for the pro version.
Click to expand...
Don
Huge thank you. Just got me the reikan focal plus version after you mentioned this. What an absolute stunning software. Easy to use. Had a lens that has given me head ache long time andi
I could not get its fine focus setting set manually. The lens was out by +16. Calibrated all my lences and whats nice is I can change lenses and my camera immediately recognise the lens and set the fine focus setting for that lens.

Seriously considering to get the pro version now.
 
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canuck257

canuck257

Senior Member
Don Kuykendall said:
I am old and my eye site is not that good so I had a lot of problems seeing the difference in +3 and 0 in the ruler so I went with a software/computer based Fine Tuning system.

https://www.reikan.co.uk/focalweb/

It is not free but I really like it. It has made a major difference in my cameras. It runs a little over $100 for the pro version.
Click to expand...

What Don said, FoCal is excellent and DOES make a significant difference. Incidentally, my eyes are 70 years old and not what they were
so using this computer based system takes them out of the equation.
 
D

Don Kuykendall_RIP

RIP :(
Johan65ZA said:
Seriously considering to get the pro version now.
Click to expand...

I have the Pro version but the only real benefit I see in it is the

[FONT=&quot]Testing of > 400mm focal length[/FONT]
[FONT=Helvetica Neue, Helvetica, Arial, sans-serif]Testing long lenses can be problematic, but it’s made much easier with the extra information provided in FoCal Pro.[/FONT]

[FONT=Helvetica Neue, Helvetica, Arial, sans-serif]The other features are just for testing and not tuning. If you have a long lens then probably would help[/FONT]

[FONT=Helvetica Neue, Helvetica, Arial, sans-serif]A couple of things I have found that really helped is choosing a paper to print the target on. I used a heavyweight mat finish photo paper. I then when to office depot and bought some foam core board that has adhesive on one side already and plastered the print on the foam core. The target has lasted me for a long time now and making sure that it does not curl should help in tuning your lenses. Also the mat paper will not give any reflections back on the camera to screw up the testing either.

If you have any super zooms like the 18-300 I would advise testing it at wide, middle and long and then averaging the numbers for the final setting in the camera. I really wish Nikon would let us fine tune for wide and tele on the same lens. would work so much better.

Opinions expressed are mine and not necessarily worth the time to read them. [/FONT]:rolleyes:[FONT=Helvetica Neue, Helvetica, Arial, sans-serif] [/FONT]
 
canuck257

canuck257

Senior Member
Don Kuykendall said:
I have the Pro version but the only real benefit I see in it is the

Testing of > 400mm focal length
Testing long lenses can be problematic, but it’s made much easier with the extra information provided in FoCal Pro.

The other features are just for testing and not tuning. If you have a long lens then probably would help

A couple of things I have found that really helped is choosing a paper to print the target on. I used a heavyweight mat finish photo paper. I then when to office depot and bought some foam core board that has adhesive on one side already and plastered the print on the foam core. The target has lasted me for a long time now and making sure that it does not curl should help in tuning your lenses. Also the mat paper will not give any reflections back on the camera to screw up the testing either.

If you have any super zooms like the 18-300 I would advise testing it at wide, middle and long and then averaging the numbers for the final setting in the camera. I really wish Nikon would let us fine tune for wide and tele on the same lens. would work so much better.

Opinions expressed are mine and not necessarily worth the time to read them. :rolleyes:
Click to expand...

Great minds think alike?? That's exactly the setup I use and I also have the Pro version purely to deal with my longer lenses.
 
F

Fat Fingers

Banned
Oh some people do make a simple thing difficult.....take an expanding rule and pull it out about 4 ft ....lay it on the ground about 25ft away and put a pencil across it at say 24 in. Stand back and photograph the pencil at -20 through in 5s to +20 .I often use a flash to ensure no movement.
examine the shots on your computer at 100% You will soon see which is sharpest at 24 in.
If you can tell no difference then either the lens combo quality is so bad its all blurred or you need to stop down a little .( or you did not press OK so did not take the shots at -20to +20
 
G

gustafson

Senior Member
Finally got around to giving AF fine tune a go this weekend. Setting up a target 52 feet away proved to be a minor undertaking. My family was rather amused that I was taking photos of a stack of cardboard packages across the yard. Nonetheless, I used the Dot-Tune method, and for a target focused in Liveview, the range for the Green Dot was -7 through 7, making me rest easy about an AF issue. I then experimented with faster shutter speeds and found that I need to be at 1/800s or faster to get sharp results from this combo. So ultimately, it was poor technique (slow shutter speeds handheld) that was robbing sharpness from my photos, not an AF issue. Thank you all for your inputs on AF Fine Tune - I plan to check all my lenses to be on the safe side, so your suggestions will be put to good use!
 
J

Johan65ZA

Senior Member
Fat Fingers said:
Oh some people do make a simple thing difficult.....take an expanding rule and pull it out about 4 ft ....lay it on the ground about 25ft away and put a pencil across it at say 24 in. Stand back and photograph the pencil at -20 through in 5s to +20 .I often use a flash to ensure no movement.
examine the shots on your computer at 100% You will soon see which is sharpest at 24 in.
If you can tell no difference then either the lens combo quality is so bad its all blurred or you need to stop down a little .( or you did not press OK so did not take the shots at -20to +20
Click to expand...
Jip but i really like to use technology if i can when it will do it for me. It is called advancing with the times and with questionable eyesite why take chances. At least i have proof now so seeing an out of tocus pic i now know the fault is with the driver.
 
F

Fat Fingers

Banned
Johan.....Using a ruler simulates taking a picture in the real world and if you cannot see the monitor put your glasses on.
Gustafson ....using the dot is not very accurate -7 to +7 that's rubbish .....you should be trying to get it down to " not sure if +5 or +6 is better ( for example)
 
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