Today’s Question: Is there a limit on how many adds one can make to a mask?
I had a situation where I could not complete a mask in Lightroom Classic. The image was of a pile of cannon balls at an old military fort. It would not select the whole pile at once. I would add to the mask to incrementally get the whole pile – almost. After about 6 add steps, it would not allow any more. It just ignored the add command.
Tim’s Quick Answer: There isn’t a specific limit to the number of mask components you can create for an image, but it is limited by system resources such as memory.
More Detail: The masking feature in Lightroom Classic (or Camera Raw) is relatively resource-intensive, which can lead to performance degradation or even the exhaustion of system resources. This is particularly an issue when using a large number of masks or complicated masks the involve a large number of components.
You can often improve this issue by simplifying a mask to the extent possible. For example, rather than adding a separate mask component for each cannonball in the image referenced in the question, you could use the Brush to paint over all the cannon balls in a single mask component.
You can also minimize this issue, of course, by using a more powerful computer. In particular, having adequate system memory (RAM) and GPU memory (VRAM) can have a big impact. Other resources such as the processor (CPU) and adequate available hard drive space can also impact performance.
This issue is compounded by the fact that the software doesn’t generate an error message when you aren’t able to add an additional mask component. Hopefully that will be resolved by Adobe in a future release so the software doesn’t just give the impression that it is ignoring you as opposed to not being able to execute the command for you.
