Sensor Dust and Spot Removal Pro

Dust and spots / Spot removal / Moiré

Remove unwanted sensor dust, spots or blemishes from images using the Spot Removal tool.

Overview of the spot removal tool Pro

The Spot Removal tool can be used to quickly remove spots or small blemishes from images. In addition to spot removal it also has an option to remove sensor dust. Although the operation using a circular cursor to retouch each imperfection is the same between the Spot and Dust modes, the two adopt different algorithms so the results will vary between them. Whereas the Spot option analyzes texture, color and brightness from the sampled area, in this case within the circular cursor, and merges that with its immediate surroundings, the Dust mode estimates the light lost and compensates with a localized exposure adjustment. It is recommended, therefore, to limit each to their intended use.

Sensor dust can be commonly seen in similar or identical locations on images from one session. Dust can settle on the front of the so-called "filter-stack" of an image sensor and may appear in varying degrees of sharpness from image-to-image, depending on the aperture selected during capture. To save time when retouching dust spots from multiple images, use the Global Copy and Apply buttons to apply the corrections. Alternatively, make a local copy of the dust spots using the Adjustments Clipboard and apply the Dust setting to the rest of the images. Always check image files when automatically removing dust spots. The Spot Removal tool works with offline images so you can continue working on a Catalog without the source files available, for example, when you’re away from the office and don’t have access to an external drive or NAS. You can use multiple overlapping selections (up to 100 selections can be made per image), however, the brush-based Heal tool is recommended when more advanced retouching is required. For more information, see the section on the Heal tool.

Removing spots and sensor dust Pro

The operation is the same for removing spots and small blemishes as it is for removing sensor dust. However, for the best results it is recommended to use the appropriate mode, depending on the issue encountered. Both types of spot removal can employed on the same image. When checking images for sensor dust, it may help to darken the image first using a negative exposure adjustment. 

  1. From the Details inspector, go to the Spot Removal tool.
  2. From Type drop-down menu, select from Dust or Spot as appropriate, and click-on the ring-shaped orange cursor adjacent to the Type field. Alternatively select the circular orange-colored cursor from the Cursor tool bar or use the shortcut (O). When the Dust option is selected, the current cursor changes to a four piece ring-shaped cursor with a crosshair. When Spot is selected, the cursor can be identified by its unbroken circular cursor with a crosshair.
  3. Magnify the image in the Viewer to 100%.
  4. Before applying, adjust the size of the circular-cursor to match the spot or dust-particle; ctrl/right-click (macOS/Windows) in the Viewer. The tool opens beneath the cursor.
  5. Adjust the Radius slider to fully cover the spot or dust-particle and click-on it to remove it. Alternatively click on the spot or dust-particle, then click-and-drag the edge of the selection ring to cover it. When active, the circular-cursor changes from silver-gray to orange-colored and the spot or dust-particle is removed.
  6. To re-position a selection, place the circular-cursor in the center of the selection-ring and drag and drop to change its position.
  7. Repeat steps 2 to 6 to remove more individual spots or dust-particles.

Removing sensor dust from multiple images Pro

Sensor dust, when it occurs, is typically seen in the same location on all images from the same camera, and particularly during the same session. Once all of the selections have been made and the dust removed from one image, you can apply the adjustments to all the images in the session. The same procedure can be used for spot-removal, with some caution, as the spots must be located in the same position in each image.

In Capture One, there is more than one method you can use. The quickest when applying to multiple images (and the Edit Selected Variants option is already enabled) is to use the local Copy and Apply command. If you haven’t decided on the image or images to apply the adjustments to (i.e., they’re not already selected or they are but the Edit Selected Variants option isn’t yet enabled) then a combination of local and global copy and apply commands must be used.

  1. Select one image from the Browser and make the selections using the Dust removal option, as previously described.
  2. Click-on the Copy and Apply button (double-headed arrow icon) in the title bar. The tool's Adjustments Clipboard dialog window opens.
  3. Add a check-mark to the Dust option, and choose from the following:
    • Copy - choose this to copy to the clipboard when you haven’t yet selected the image or images you want to apply the adjustments to (i.e., if the Edit Selected Variants option is not already enabled). The adjustments are copied to the clipboard (this includes both the local clipboard and global adjustments clipboard).
    • Apply - to copy and apply to one or more images if the Edit Selected Variants option is already enabled. The adjustments are copied to the selected images.
  4. If you selected Copy in step 3, select the image or images (when applying to multiple images, enable the Edit Selected Variants option) and press the Apply button in the main toolbar (downward slanting arrow icon), or the Apply button in the Adjustments Clipboard.
  5. The adjustments are applied to the selected image or images.
  6. Always check images afterwards when automatically removing sensor dust, and particularly so if removing spots.

 

Switching between spot and dust removal in the viewer Pro

You can switch between the Dust and Spot options quickly from image-to-image, or even on the same image directly from the Viewer.

  1. With the Spot Removal cursor selected, ctrl/right-click (macOS/Windows) in the Viewer. The Spot removal Settings dialog window opens beneath the cursor in the Viewer.
  2. Click on the field adjacent to Type and select the appropriate option from the menu.

Clearing selections from the viewer Pro

  1. When you've finished working with the Spot Removal tool, switch to another cursor such as the Pan (H) or Select (V) cursor. This will clear all of the ring-shaped, dust/spot removal cursors from the Viewer. Any sensor dust or spots that have been removed will stay hidden. 
  2. To continue using the Spot Removal tool on the same image, re-select the circular cursor from the Spot Removal tool or Cursor group. Any previous selections made will be recalled and displayed for further editing.

Deleting specific selections Pro

Each time a selection is made a selection-ring indicates the position in the image and it is recorded and numbered in the Spot Removal tool. To highlight the individual selection, you can either select it directly from the Spot drop-down menu if you know the position, or navigate through each selection using the forward / backward  > / < buttons in the tool. The selection is highlighted in the Viewer. If you have made multiple selections, however, it’s unlikely you’ll know what number it is. If you select the circular cursor in the Viewer, the numbered position will be displayed in the Spot field of the tool.

  1. To delete a selection, either select it from the list in the Spot drop-down menu in Spot Removal tool, or in the Viewer so that it changes from silver-gray to orange and choose from one of the following:
    • Press the backspace/delete key 
    • Press the delete button (-) icon in the Spot removal tool.
  2. The selection is deleted. If there was a spot or dust particle beneath that selection it will re-appear.

Deleting all selections simultaneously Pro

  1. To delete (reset) all the spot/dust adjustments in an image without affecting any other adjustments made, click on the local reset button (curved arrow icon) in the Spot Removal’s title bar. 
  2. To delete spot/dust adjustments on all selected variants, shift-click on the local reset button.
  3. To temporarily delete all the spot/dust adjustments, option/alt-click (macOS/Windows) on the local reset button.

 

Save selections as a style Pro

You can save the dust-removal adjustments, as a kind of "dust map" for that specific camera, for the following sessions.

  1. Go to the Adjustments inspector and from the Adjustments Clipboard panel, verify the Dust option is enabled and all others are disabled.
  2. Click-on the Action button (… icon). The Action menu opens.
  3. Select Save as Style… from the menu. A system dialog window opens.
  4. Give the style a meaningful name, such as [Camera Model]_Dust_Map_[Date] and press Save, or Cancel to reject and return to the app.
  5. When automatically removing sensor dust, always check images afterwards.