Nikon D300 Complete Manual page 401

Hide thumbs Also See for D300:

Table of Contents

Two things to notice about that chart. First, I've tried to leave

high contrast edges near the center for the camera to "grab"

during focus. This chart isn't ideal in that respect, but works

okay. In general, you want to avoid very small detail for your

focus target, such as newsprint, as you need something large

enough for an individual focus sensor to grab but not so large

that the sensor sees an area of no detail.

Do not use this (or other) chart at an angle to the camera as

some have suggested. You'll get more accurate tuning if you

shoot perpendicular to this chart.

But the real interesting thing about using a chart like the one

on the CD is that it tends to generate clear moire patterns

when focus is achieved (less so when using it on LCD

monitors than when using CRTs or printed copies, though). At

least it does if you're the right distance away from it. I have a

printed ISO focus chart I use when I'm not in a hurry, but

those charts are probably too expensive for most users, and

I'm getting essentially the same results with the quick chart

I'm supplying you.

You also need to have the chart at about the normal distance

you'd be using the lens and the camera not only on a sturdy

support (e.g. a good tripod and head) but also perfectly

oriented perpendicular to the flat chart.

Here's the trick for that last bit: place a mirror on the middle

of the chart. When you can see the camera centered in the

mirror as you line up the chart, you're perpendicular.

Finally, make sure you're using the largest aperture on your

lens so that you have the minimum depth of field.

Thom Hogan's Complete Guide to the Nikon D300

Troubleshooting