What is the difference between the Spot and Dust options in the Spot Removal tool? When should I use those?
The Spot Removal tool is intended for light retouching of images. It has two methods available: Dust and Spot. Each of those can be used to do light retouching of images depending on the root cause and severity of the spot. Do note that the Spot Removal tool is limited to 100 corrections per variant.
To access the Spot Removal tool, navigate to the Details tab in the Tool Tabs area.
In a nutshell, the Spot option is used to repair a problem in the scene of the image. The Dust option is used to fix a spot of dust on the sensor which shows up in the image.
The Dust option can repair image defects caused by dust on the sensor that obstructs up to two stops of light. The speckle of dust must appear out of focus, which is typically the case with an object close to the sensor at moderate apertures.
Dust speckles residing on the sensor remain at a fixed location. As such, it may be advantageous to locate the spots carefully on one image and apply them to all images taken at the same shoot. The correction applied will be specific to each image and the information within the area of the correction.
Check the examples of the Dust function in action.
The Spot function should be used to correct more severe problems, particularly those in the scene captured. This is often necessary when the lens is stopped down so that even tiny speckles can obstruct the light completely and/or have halos due to diffraction. The Spot method is aimed to repair the image, assuming that it is completely ruined in the marked area. Thus, it may also be useful for retouching images with any unwanted artifact. We use an intelligent neighbor pixel calculation that incorporates additional elements including feathering and color blending.
Check the examples of the Spot function in action.
In the examples of Dust and Spot corrections above, the circles are indicative of where the correction is applied. They are visible when the Dust or Spot cursor is selected. The circles themselves will not appear in the processed files.