I found some instructions to the Zeiss Optical Test Pattern which is similar to the USAF pattern.
Installation of Use of Optical Test Pattern
It is recommended this pattern be positioned at a distance of 15' in the store affixing the top portion to a smooth surface. This location should be visible from the sales counter but be positioned in a area with poor lighting.
For proper comparison only use optics of identical magnification or very similar and have similar objective diameters (See below example). Viewing should be from a supported position. LOCATE THE TEST PATTERN IN THE CENTER OF EACH FIELD OF VIEW.
OK &nbs p; &nbs p; NOT OK
8x30 with 8x30 &n bsp; 8x30 with 7x35
8x30 with 8x35 &n bsp; 8x30 with 7x30
10x40 with 10x42 & nbsp; 8x30 with 10x50
SPECIAL NOTE: Eyeglass wearers should be requested to leave their corrective eyeglasses on and utilize the roll down or twist-up eyecups if comparing binoculars.
1. Have the customer focus the pattern as sharply as possible for each set of optics and note the number on a piece of paper.
2. Request that the customer check to see that all lines, regardless of their direction, are clearly in focus at at the same time for any size pattern. Example: If the lines running horizontally are sharply in focus, but the vertical lines are not, this is an indication that the lens has an aberration called "Astigmatism".
3. Compare each optic for image contrast. If the blacks and whites tend to be grey, then it is and indication of poor quality.
Move the optic so that the test pattern is now one third of the way out of the center field of view and repeat steps 1-3. Move the optics so that the test pattern is now at the very edge of the field of view, and repeat steps 1-3.
NOW COMPARE NOTES: You probably found that in most optics, the image quality changes dramatically from the center to the edge of the field of view, and this is especially noticeable in the "wide angle" optics.
You probably also found that each step along the way, the Zeiss optic will generally outperform all others: that the changes in image quality from center to the edge of the field of view is more nearly consistent in the Zeiss optic.