Most of the cameras use a light measurement device to guarantee the best exposure to the pictures, to assure the best balance of details as in the low to the high lights.
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Mastering the pictures exposure
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Despite the relative accuracy of automatic functioning (spot metering, center-weighted and matrix metering), the use of an exposure card could be useful, indeed essential.
On indoor or outdoor shot, the Scuadra XpoGrey exposure card is used as a referential to define in the best way the optimum exposure for all the pictures.
A single spot metering on the main area (18% medium grey area) is enough to find the optimum exposure for every kind of subject, in all shot situations. |
18% Medium Grey
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The photometric calculation data for an optimum exposure of sensitive surfaces (emulsion or sensor) are determined with an 18% grey. This means a grey reflecting 18% of the light received. Today, every camera photocells or photosensitive devices are still adjusted on this 18% grey. |
On production or postproduction, a grey levels scale permits to control very accurately the exposure of the pictures. It covers an exposure of -2 IL to +3 IL by half diaphragm increment (of -2 to +2 IL XpoGrey Compact). For example, when the clearest or darkest patches are too similar, it shows significantly when a picture is over or under-exposed.
To satisfy professional exigencies, all the areas (main area and levels scale) are measured with a spectrophotometer. The targeted values are known and written on the Lab zone under each grey area*.
Professional quality and all-terrain
Thanks to his dull surface, the XpoGrey exposure card reduce brilliance and glares to the minimum to give to the user a great work flexibility.
Dimensions of the Scuadra XpoGrey are 180x115 mm (7.1x4.5 inches) for the medium size and 90x55mm (3.5x2.2 inches) for the compact size. Made of high-density polymers with 4 mm depth, it is very resistant and will be easily put away in your carryall.
Besides, to assure the colors stability in time, the XpoGrey exposure card is guaranteed with no optical bleaching agents and with neutral pH.
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• A black and opaque suitable flex case is provide with each Scuadra XpoGrey exposure card. It protects it and keeps it away from light when not in use (stability of the shades in time). |
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• To help focusing, a target is present on the exposure card. Its dimensions are defined to not altering the measurement of the medium grey area. Whatever the targeted zone of this 18% area is, the exposure provided is optimum. |
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• Two size scales (one in centimeters, the other in inches) are present on the exposure card. They give a useful referential for different kinds of photographic works. Only the centimeters scale is available on XpoGrey Compact. |
Scuadra XpoGrey characteristics
Dimensions XpoGrey Medium: 180x115 mm (7.1x4.5 inches).
Dimensions XpoGrey Compact: 90x55 mm (3.5x2.2 inches).
Depth: 4 mm.
No optical bleaching agents and neutral pH.
Total exposure control (18% grey and levels).
Hard polymers support 4 mm depth.
Individually measured (With Lab values*).
Suitable flex case (protect and secure).
* XpoGrey Medium only
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Photo Accessories & Color Management
