Vignette Read-me file.
About Vignette
Vignette is a plug-in for Photoshop to add or remove luminance fall-off in digital images
Disclaimer: This software is provided "as is". No warranties of any kind, expressed or implied, are given. Not even to its functionality, use and applicability. Read the License agreement for further information.
Contents of this Read-me file:
1. Installation
2. Preview
3. ProfileType
4. LensType
5. Luminance
6. Adjust Relative To
7. Known issues and incompatibilities
1. Installation
Step 1: Move or Copy the filter plug-in to your Photoshop filters folder;
Step 2: (re)start Photoshop;
Step 3: Open an RGB image, the filter should then be available under:
Filter --> theimagingfactory --> Vignette...
Note: you can move the entire folder, including this ReadMe file, to your Photoshop Filters folder. Photoshop will automatically detect the appropriate plugin file during startup.
Tip: Holding the alt-key will change the Cancel button into a Reset button. Selecting Reset will revert all parameters to the settings last used.
Holding both the alt-key and shift-key simultaneously will change the Cancel button into a Defaults button. Selecting Defaults will revert all parameters to the factory defaults.
2. Preview
This plugin shows the results of its calculations in a preview pane. To better judge the effect of your settings the preview can be zoomed by the zoom-buttons below the preview pane indicated with a "+" (plus) and "-" (minus) symbol. Alternatively you can use the cmd-"+" or cmd-"-" key sequence.
A percentage of scaling is given between the zoom buttons. You can click the percentage text to quickly switch between 100% and best fit. If the preview is larger than the preview pane you can quickly scroll through the preview by clicking the mouse in the previewpane and subsequently draging the preview.
The preview checkbox next to the preview pane allows you to switch between previewing the original data and previewing the filtered data. Mac users can use the ctrl-space key sequence quickly switch the preview checkbox.
3. ProfileType
The profile popup lets you select the luminance fall-off profile of your lens. You can either select a profile corresponding to the 4th power Cosine law, or you can create a custom profile. The Cosine 4th law is usually correct for most situations. The corresponding profile is determined by the exit-angle of a lens/camera combination. You therefore have to select a lenstype (see below).
To create a custom profile you have two choices. You can create a Radial profile, or a Spatial profile. A Radial profile is determined by taking samples radially from the center of the picture outwards, and then averaging these samples into one single profile. This profile is then applied to the image radially. A Spatial profile is determined by taking samples from a grid over the entire image. A Radial profile is best suited for most situations, a Spatial profile could for example be used for Flash-patterns.
To create a custom profile:
1. Take a picture of an evenly lit, evenly colored surface. It should preferably be neutral colored and correctly exposed, but neither is necessary. It should however not be over-exposed.
2. Open the picture in your image editing application and select the Vignette filter from the filter menu.
3. Select "Create Radial" from the ProfileType menu, and wait until it jumps to "Custom".
The filter has now created a Radial profile. The picture should show an evenly luminated tint. If you still see some luminance fall-off in any corner, you may want to create a Spatial profile instead. You can use the Save button to save the current parameters to disk.
4. Select OK to apply the filter once, so it retains the profile in its settings.
5. Open an image that requires correction, and select the Vignette filter again.
6. Adjust the Luminance slider as desired, and select OK to apply the filter.
If you create a Spatial profile for a Flash pattern this way, it should be done at approximately the same distance as the flash usage in the actual image to be corrected. You may want to blur the surface image somewhat if necessary.
4. LensType
If a Cosine 4th profile is selected, you have the option of selecting a corresponding lenstype. The Cosine 4th profile is determined by the exit-angle of a lens. To select an exit-angle, select the type of lens from the LensType menu. This will show a corresponding focal-length from which the exit-angle is determined. Note that for some lenses such as retrofocus style lenses this relation may not be exact. But because of the separate luminance adjustment control, you will usually be able to exactly correct your images. If a custom exit-angle is desired anyway, you can select "custom" from the lenstype. This will show you a dialog allowing you to enter a custom exit-angle.
5. Luminance
The Luminance slider allows you to add or remove luminance in a picture according to the profile selected. Positive values will brighten a picture, negative values will darken a picture.
6. Adjust Relative To
This popup allows you to select the direction of correction, or which way the contrast is preserved. For most images you would like to correct relative to white. The luminance of the image is "damped" to the sides so you want to "brighten". However, for astrophotography for example, you may want to do the opposite instead; the luminance of the middle of the image is too bright, and you want to reduce luminance (toward black) while preserving the contrast of the bright stars in the image. In this case select Relative to black.
7. Known issues and incompatibilities
- For the NT family of OSes this plugin requires Windows NT 5.0 or higher!
- The windows versions will occasionally not update its values when first selecting a slider followed by immediate dragging. In this case, briefly release the mouse, then resume dragging.
For questions, suggestions, comments and other issues regarding this product, or for general information regarding all of our products you can visit our web-site at www.theimagingfactory.com.
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