MEGA USER GUIDE

INSTRUCTION FOR CHART INSTALLATION :

 

Place the chart in vertical position.

There is 2 options :

 

1/ Use a metallic surface to magnet the chart

2/ Slide the chart inside the slot of the bracket
and lock it with the 2 plastic screws.
Mount it on a stand (not supplied) using the 1/4’’ nut below.

USER MODE :

Frame the center of the chart. The optical axis has to be perpendicular to the chart, so the chart is parallel to the image plane.

1/ Flatness check

Place the camera at a distance that let you full frame the width of the chart*. This mode enables you to check the sides sharpness aberration of your lens compared to the center. It also helps to detect potential flatness problem of the sensor or optical lenses.

* We don’t recommend to place the camera below 2 feet from the chart (short focal-lengh).

 

 

2/ Optimum check


You have the possibility to check mathematically the resolution of your sensor or your lens. This can be very useful to compare different sensors and lenses. For this mode, use the numbers of each circular and linear targets on the chart.
The numbers in the concentric and linear targets, in twentieth of a millimeter, express the distance between the two axis by two black (or white) consecutive lines.

USER MODE OF THE CORRELATION TABLE :

The correlation table gives you the correlation between the numbers in the concentric and linear targets, the number of pairs of lines printed on the chart on 1 millimeter and the number of pairs of lines printed on the film or sensor on 1 millimeter.

The numbers in the concentric and linear targets, in twentieth of a millimeter, express the distance between the two axis by two black (or white) consecutive lines.

To use this correlation table, place the chart at a distance from the image plane 50 times the focal lengh of the lens to be tested (in either millimeters or inches).

Example for a 50 mm lens :

50 x 50 = 2500 mm = 2,5 meters = 8 feet

Analyse your lenses and print them with stop wide open.

The degree of sharpness depends on the clarity between the lines. The resolving power depends on the number of lines seen.

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