EXIF data query

[aesop]

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...quick question - what do the terms "Max Aperture Value" and "Shutter Speed Value" refer to? I just saw them whilst viewing some EXIF data and the resulting values don't make sense to me.

[jankap]

In Photoshop I find as an example one camera parameter of my Dux-4: max aperture f/2. And extra: used aperture 2,8.

Sigma Photo Pro only offers the actual data of the photo, no camera data.

Does this help?

Jan

[mjh]

MaxApertureValue ist the maximum lens aperture specified as an unsigned rational number. ShutterSpeedValue is the shutter speed specified as a signed rational number. Both are APEX values. The relationships between those APEX values and the more useful f-numbers or exposure times are:

 

f-number = 2^(MaxApertureValue / 2)

 

exposure time = 2^(–ShutterSpeedValue)

[ho_co]

Michael--

Please remind me once again: What is APEX?

[mjh]

APEX is short for “Additive System of Photographic Exposure” (see APEX system - Wikipedia, the free encyclopedia). APEX values for shutter speed, aperture, exposure, and ISO speed are all logarithmic so you can, for example, add the ApertureValue to the ShutterSpeedValue to give the ExposureValue – thus the “Additive” in “Additive System of Photographic Exposure”.