Better Light 7 manual Histogram, Judging Overall and Spot Exposures

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Histogram display of a Macbeth ColorChecker® with six static spot meters and the dynamic spot meter display.

Histogram

In addition to the location-specific image information provided by the spot meter, a histogram display presents overall image expo- sure information at a glance for the currently selected crop area. This display has a horizontal scale from zero to 255, representing the pos- sible 8-bit data values for the image data (either any single color or an average of R, G, and B for “gray” data). The vertical scale repre- sents the relative population of each data value by means of a black vertical line whose height varies from zero to full scale according to the frequency of occurrence of that data value in the preview image.

By evaluating the shape and location of the histogram data (black areas), the overall range and domi- nant areas of image data can be quickly determined.

To provide the maximum amount of useful exposure information, the histogram display is usu- ally set to clip very high readings for dominant data values, to allow lower readings to be seen more prominently. This mode will often produce a flat-topped peak in the dominant data area, but clearly shows the remaining distribution of data, which is often more important than the relative heights of the distribution. This histogram clipping can be turned off by “normalizing” the data display. When normalized, the most frequently-occurring data value is set to exactly the full vertical scale, and all remaining data values are adjusted accordingly. This mode more accurately represents the distribution within dominant peaks, but may make large portions of the less populous data range too small to dis- play. To switch normalization on or off, select Normalize Histogram from the Display menu, or use the Command-N keyboard (Control-N in Windows) shortcut. A checkmark beside the Normalize Histogram submenu item indicates that normalization is on (no data clipping).

Clicking the mouse in the histogram display will scale the histogram vertically by a factor of two for each click. This feature can be used to see small peaks that would otherwise go unnoticed. Holding the Option key and clicking in the histogram will reset the display to the original scale.

Judging Overall and Spot Exposures

The histogram display directly indicates the overall exposure and contrast range of the preview image, allowing proper exposure determinations even when using portable computers with lower quality image displays. Just as the spot meter is used to read the data values of specific image loca- tions, the histogram is used to read the data values of the entire image. The spread and distribution of data values in the histogram can show under- or over-exposure, and whether an image will be low- key (dark) or high-key (bright), contrasty or flat. If a significant portion of the image data is piled up

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Contents Revision D March Large Format Digital Scanning Camera SystemAcknowledgements Page Page Contents Locking Both Lock Crop RatioAltering Color Balance for Mood or Effect Audio Focusing Aid Multiple Color FocusingSaving a High Bit Depth Image Limit LineAutomatically Opening the Image Exporting NotesLine Time Hardware Setup Software OperationLighting Parts List Connector Identification Getting Started Installing and Configuring the ViewFinder SoftwareSystem Requirements Memory RequirementsMacintosh PC PC version of the software is requiredConnect the camera insert to the control unit Quick Start GuideConnect the control unit to the host computer Mate the female end of the cable with the DBInstall the viewing overlay on the camera’s ground glass Connect the AC power to the control unitTurn on the digital camera Turn on the host computerMm thick Tungsten infrared blocking filter Install the infrared blocking filterCompose and focus the image Select the image capture settingsPut the insert into the camera Start the ViewFinder softwareTake the picture PrescanTransfer the file to the computer View the final imageMaking a Prescan PrescanningFast Prescans Cropped Prescans Super View Prescans Saving and Viewing Prescans Canceling a PrescanColor Managed Prescans Guides RulersResolution Image Capture SettingsPage Line Time ISO Exposure Lock Capture ModeScanning Canceling a ScanScanning to the Camera Disk Automatically Naming Images Naming the ImageAdding Notes to Your Picture Digital Spot Metering Exposure EvaluationRGB Data Values, EV Units Determining Relative Exposure Static Spot Meter Tool Setting the Spot Meter Size Judging Overall and Spot Exposures HistogramStatic Spot Meter Location Readings Magnify Tool Tool BarHand Tool Panorama Tool Measure Tool Mac onlyToneZones Tool Page Grid Tool Crop Mask ToolPage Size Panel Tab PanelsScan Area & Cropping Different unit. Example 15.24 cm x 10.16 cm at 300 pixels per Size of the cropped area may still be adjusted whileClicking up or down buttons of Scan Area Lock Crop Ratio To set a specific shape for crop rectangleLock File Size To specify an exact file size Seconds Scan direction Faster Scans for FreeEstablishing Neutral Color Balance Color PanelSaving Color Balances Deleting Color Balances Changing Existing Color BalancesAltering Color Balance for Mood or Effect Tagging Images with ICC Profiles Reverting to a Previous Color BalanceTone Curve Selections Tone PanelSaving a High Bit Depth Image Brightness/Contrast Tone Curve Adjustments Manual Tone Curve Adjustments Spot Meter Reference Points Limit LineNegative Curves Bit Tone CurvesTone Curve Histogram Setting the EV Scale ReferenceSelecting an Output Tone Scale Deleting Tone Curves Saving Tone CurvesLarge Focus Display Focus PanelSelecting a Focus Site Reading the Focus Displays and Adjusting Focus Multiple Color Focusing Audio Focusing Aid Mac onlyInfrared Focus Image File Management and Retrieval ViewFinder File Manager Adding more Notes to Your Pictures Sorting Image FilesExporting Notes Automatically Opening the Image Automatically Saving Files to a FolderRetrieving Image Files Selecting the Retrieval Tone Curve USB controller only Hard Drive Storage Capacity Deleting Image FilesFile Menu MenusEdit Menu Display Menu Camera Menu Clean/Park Capture ModeDiagnostics Opens the Clean/Park window to expose the CCD for cleaningAutomatically Retrieving Images Saving Files User PreferencesAfter highlighting the desired folder, click Right of the Save scan folder labelAuto Naming Automatically Save PrescansAutomatic Scan Viewing in an Application Auto File Open Mask Auto-rotate Retrieved FilesGuides GridBaseline ISO Setting Using SoundsISO Increment Selection Use this feature, the factory settings are adequate Pano SettingsTime Lapse CropAppendix a Cleaning the CCD Cover GlassAppendix B Exposure AdjustmentsManipulating Exposure Line TimeTone Curves Color Balance SensitivityLens Aperture Lighting Appendix C Line Time SettingsAppendix D Resolution SelectionsModel 4000E-HS Model 6000-HS, 6000E-HSSuper 6K-HS Super 8K-HS Power Status IndicatorsAppendix E StatusAppendix F Hardware SetupPanoramic Adapter Scene PanoramaPage Rollout Panorama Hardware is assembled just as it is for a Rollout panorama Object PanoramaCamera reported error Not Ready Error MessagesCamera reported error No Room Camera reported error Conversion ErrorCamera reported error Math Error Camera reported error Value ErrorScsi Errors Comm returned error Other Errors Unknown ErrorCamera Timed Out
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