MEGA CHART 27 X 38 CM
BOX CONTENTS
The Mega chart by P.A.T. Accessories has been specially made to calibrate cameras and lenses that become increasingly technical and sensitive, 8k and over. Specially thought for users, it has all the main features in a comfortable size to help you check the sharpness of your lens and your camera, in a studio or on the field.
All you need to calibrate your camera and your lenses is now in one box.
Chart 27×38 cm / 1’3’’x11’’
Magnetized plexiglass support. Thickness 4 mm.
Aluminium bracket with 3x 1/4’’-20 nut.
2x 1/4’’-20 thumb screws.
Wotersoluble pen
Universal adaptor 1/4’’M – 3/8’’M
PU storage bag
TECHNICAL CHARACTERISTICS
Dimensions 27×38 cm thought for field use
Circular targets
Until 250 pairs of lines printed on the sensor
Linear targets
Anti-bending support
Siemens targets
Magnetic support
Neutral grey
Aluminium bracket to mount the chart on a stand
Writable annotation areas
Mate coating
Fits in cabin baggage for air travel
INSTRUCTIONS FOR CHART INSTALLATION
Place the chart in horizontal position.
2 options :
The chart can be mounted on a metallic surface
(iron, steel, etc.) due to magnetized backing.
Slide the chart inside the slot of the bracket
and lock it with the 2 thumb screws.
Mount it on a stand (not supplied)
using the 1/4’’ nut below.
INSTRUCTIONS
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.
SHARPNESS TEST
The P.A.T. charts give you the possibility to check mathematically the resolution of your sensor or your lens.
For this mode, use the numbers of each circular and linear targets.
The numbers in the concentric and linear targets, in twentieth of a millimeter,
express the number of pairs of lines printed on 1 mm.
The table below 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.
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.
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.
CORRELATION TABLE
