## Composite Tags

The values of the composite tags are derived from the values of other tags. These are convenience tags which are calculated after all other information is extracted.

> Tag Name | Writable | Derived From | Values / Notes
> --- | --- | --- | ---
> Aperture | N | FNumber ApertureValue |
> CFAPattern | N | CFARepeatPatternDim CFAPattern2 |
> CircleOfConfusion | N | ScaleFactor35efl | (this value may be incorrect if image has been resized)
> ConditionalFEC | N | FlashExposureComp FlashBits |
> DOF | N | FocusDistance FocalLength Aperture CircleOfConfusion | (this value may be incorrect if image has been resized)
> DateTimeCreated | N | DateCreated TimeCreated |
> DateTimeOriginal | N | DateTimeCreated |
> DriveMode | N | ContinuousDrive Self-timer | 0 = Continuous shooting 1 = Self-timer Operation 2 = Single-frame shooting
> FlashOn | N | FlashBits Flash | 0 = Off 1 = On
> FlashType | N | FlashBits | 0 = Built-In Flash 1 = External
> FocalLength35efl | N | FocalLength ScaleFactor35efl | (this value may be incorrect if image has been resized)
> GPSDateTime | N | GPSDateStamp GPSTimeStamp |
> HyperfocalDistance | N | FocalLength Aperture CircleOfConfusion | (this value may be incorrect if image has been resized)
> ImageSize | N | ImageWidth ImageHeight |
> JpgFromRaw | Y | JpgFromRawStart JpgFromRawLength |
> Lens | N | ShortFocal LongFocal FocalUnits |
> Lens35efl | N | ShortFocal LongFocal FocalUnits Lens ScaleFactor35efl |
> LensSpec | N | Nikon:Lens Nikon:LensType |
> PreviewImage | Y | PreviewImageStart PreviewImageLength PreviewImageValid |
> PreviewImageSize | N | PreviewImageWidth PreviewImageHeight |
> ProcessGeoTiff | N | GeoTiffDirectory GeoTiffDoubleParams GeoTiffAsciiParams |
> RedEyeReduction | N | CanonFlashMode FlashBits | 0 = Off 1 = On
> ScaleFactor35efl | N | FocalLength FocalLengthIn35mmFormat FocalPlaneDiagonal FocalPlaneResolutionUnit FocalPlaneXResolution FocalPlaneYResolution CanonImageWidthAsShot CanonImageHeightAsShot ExifImageWidth ExifImageLength ImageWidth ImageHeight | (this value and any derived values may be incorrect if image has been resized)
> ShootingMode | N | CanonExposureMode EasyMode |
> ShutterCurtainHack | N | FlashBits ShutterCurtainSync | 0 = 1st-curtain sync 1 = 2nd-curtain sync
> ShutterSpeed | N | ExposureTime ShutterSpeedValue BulbDuration |
> SubSecDateTimeOriginal | N | DateTimeOriginal SubSecTimeOriginal |
> ThumbnailImage | Y | ThumbnailOffset ThumbnailLength |

<-- ExifTool Tag Names

(This document generated automatically by Image::ExifTool::BuildTagLookup)
Last revised Aug 22, 2005