D300 AF Fine Tune

[py6km]

Anyone tried this with any of their lenses yet?

I want to give it a try with a few of mine - just wondered how people went about it. There's a 45deg test, or a 90deg one - no idea which to use. Some people have concluded that the 45deg test is flawed. I'll probably opt for the 90deg (parallel) one simply because it'll be easier for me.

I may actually find a use for Lightroom hot folders (I'm thinking camera tethered to laptop with hot folder set up to view results of shots for the tests 'live').

[Tobers]

I'm going to try this on my 1D more because I can than because there is a problem with any of my lenses. I might find I can make things better though - you never know.

Isn't the sequence something like laying a newspaper/ruler down flat on a table, putting the camera on a tripod looking down at 45 degrees to it, setting the aperture to the widest possible, and focusing on a particular spot. Check the resulting image and adjust accordingly. One of the Canon people suggests taking 1 shot at each of the major 5-point intervals i.e. -20, -15, -10, -5, 0, +5, +10, +15, +20, finding the one you like best, then taking shots at single adjustment intervals 5 points either side.

And what are hot folders in Lightroom then??? Haven't found those yet!

[py6km]

Yeah, that's what I thought, although there are some dissenting opinions (somewhere, can't remember where now) that suggest that the 45 degree part makes the testing invalid for some reason. Instead, you should tack the newspaper or whatever to the wall and focus directly onto it. I've no idea to be honest, but will see what the results are like with both seeing as though I have the time over xmas because the office shuts down until 2 Jan!

Hot folders - just a watched folder; any new image that appears (eg on the HDD, or from the camera) will automatically be put into the hot folder so that you don't have to import it. Relatively useful for this kind of thing.

[Biscuit761]

Can you do this on a D50 ?

Bill

[py6km]

Originally Posted by Biscuit761

Can you do this on a D50 ?

Bill

No, only the newest Nikon and Canon cameras have this function

[m488dkw]

Some people suggest that the 45 degree test is flawed as you are asking your camera to focus on a target that is at different distances (however small) from the sensor - Nikon suggests that this can lead to autofocus inaccuracy.

There is heated debate on this over on the Nikonians forums.

[Tobers]

I just tried it myself using a newspaper stuck to a door down the hall. I followed the instructions below (the overall method should be the same for your Nikon). I ended up settling at +4 on my 70-200 F4L but the difference between the out-of-the-box 0 setting was very marginal. I'll need to go and try it out in the daylight tomorrow and see if there's any difference.

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There are many ways to focus calibrate a lens to the 1D III, but they all have the same goal - find the sharpest setting for the combo. Under good light, setup a flat focus target with obvious, contrasting lines/patterns (a newspaper, print, poster or similar printed item will work fine). Lock your camera onto a good tripod at the distance you would be most likely to use the lens at (optimally) and aimed directly at the flat focus target. Get your exposure setting correct at the lens' widest aperture (makes evaluating the test pictures easier). I select center-point-only for my focus point and use the 2-sec self-timer drive mode (optimally with mirror lockup engaged). Then, go into the menu to C.Fn III-7 AF Microadjustment (Custom Function Menu III, function 7). Select "2:Adjust by lens". Then shoot a test shot from a -20 setting to a +20 setting using increments of 5 between each shot. Then load the pics into a computer and determine which 2 settings were sharpest where the focus point was placed. Now shoot the test again using the 6 settings between and including these two settings - adjust by 1 between each shot. Determine which setting was optimal using the computer and make it the final setting for the lens. Repeat the focus adjustment process for the rest of your lenses.