Simple auto-focus calibration for DSLRs with adjustable settings.

kevy73

kevy73

Senior Member
That sounds pretty cool and feasible.

Will have to give it a try! I know my 85mm f1.4 is out by +11... will see if I get close to this when I do it this way.
 
J

J-see

Senior Member
I retuned my 300mm today after I noticed she was getting a bit soft at times. I had to dial her back by 2. I don't know if weather or "wear" is a factor.
 
C

Camera Fun

Senior Member
Just finished going through the process. Set my 18-105 at -7 and my 70-300 at -5. I will admit I didn't keep changing the distance from the target for differing focal lengths through a lens; only so much space in my house. I did run more than one test at different focal lengths; occasionally getting some strange ranges (even with setting back button focus) and eliminating those trials.
I like this system much better than using some type of angled target. I always struggled with that system; getting the targets aligned properly, being careful not to move the camera/tripod when removing/replacing the card, and especially when trying to judge the actual focus point on my computer screen. I just wasn't getting consistent results.
 
P

Paganman2

Senior Member
In the D7100 manual under the micro focus adjustment it states that adjustments made might affect the camera/lens accurately focusing at infinity, why is this as most of the things i shoot are near to or at infinity.

P.
 
L

Love Nikon

Banned
I think they ar just saying that the exact fine focus tune varies with the zooms focal length and if you get it spot on at the wide end it might be out at the tele end. This is why most peope set it at the longest focal length.
This has never been a problem for me but if you get it out by a large amount it can affect the ability of the lens to focus in low light
 
canuck257

canuck257

Senior Member
I had a few spare hours this morning so I thought I would put my lenses through the "Dot Focus" procedure. Because of limited space I did all of them at the same distance from the target. 18-55mm, 18-140mm 50mm f1.8, 70-300mm, Tamzooka. It's interesting that a couple of them had a range that was all on the plus side of zero. The focus ranges varied in length from 11 to 25 units.

There are a couple of things that I am not sure of though. When the adjusted value is saved, what is entered into the "default" setting? Am I correct in assuming that A/F Fine Tune has to be switched on for these saved values to be applied by the camera otherwise it defaults to zero?
 
S

skater

New member
I was playing with this last night, using this method (which someone linked to, but I can't find the post). YIKES. Minus 20 and it's still not quite right, with two lenses. The difference between live view and the viewfinder focus was apparent even before I started zooming in. I always thought the "noise" I was seeing close up was from pixel peeping or the anti-alias filter, but that all went away with the live view focus.

I'm going to try it again with better lighting. If I send my D7000 in for repair, I want to be certain it actually needs to be repaired.

What got me wondering was that my Tokina 11-16 lens often seems to struggle with focus at anything other than 11mm. I took some pictures of a DC-3 at the Henry Ford Museum with it, and the 11mm picture looks reasonably crisp and clear, but the ones where I zoomed in a bit were badly focused, and I had to delete them. Of course, it's possible the Tokina has some issues of its own, too.
 
L

Love Nikon

Banned
I never found the live view and dot method very accurate ..just try the ruler on the floor and use flash ..saves messing with a tripod ..do it at the longest focal length only. Another member was complaining about bad focus until he realized he was using jpeg and had not set the sharpness to +9 ( does not affect raw)
Single centre AF-S focus when testing.
 
S

skater

New member
Love Nikon said:
I never found the live view and dot method very accurate ..just try the ruler on the floor and use flash ..saves messing with a tripod ..do it at the longest focal length only. Another member was complaining about bad focus until he realized he was using jpeg and had not set the sharpness to +9 ( does not affect raw)
Single centre AF-S focus when testing.
Click to expand...

If that post was aimed at me, I was definitely using RAW, AF-S, single spot focusing. I also set the camera to self timer mode so that my hand wouldn't move the camera by accident.

The tripod is nice because it's not moving around. I know that's not a critical element, but it does help reduce variables - picture A and picture B should be identical, but they aren't, so you know why.
 
B

Bikerbrent

Senior Member
kevy73 said:
That sounds pretty cool and feasible.

Will have to give it a try! I know my 85mm f1.4 is out by +11... will see if I get close to this when I do it this way.
Click to expand...

Hey Kevin, back on 06-15-2015, you posted this. Did you ever actually try this and if so, what was the result? I am still debating rather or not to try this,
 
Top