Author: Tim Grey

Today’s Question: Can you explain what exactly is meant by the option to intersect a mask [or selection]? I understand the options to add or subtract, but can’t wrap my head around intersect.

Tim’s Quick Answer: The intersect option involves modifying a mask or selection to only include the overlap between the existing mask or selection and a new mask or selection. I recommend thinking of the intersect option as providing a way to say “subtract everything but this”.

More Detail: Admittedly, the intersect option for masks and selections can be a little confusing. Adding to a selection or mask is rather straightforward, as is subtracting from a selection or mask. The intersect option isn’t quite as clear.

Let’s assume you have a mask or selection of three hot air balloons in the sky, but you only want to modify the middle balloon. One approach you could take would be to subtract the balloon on the left and then subtract the balloon on the right, leaving only the balloon in the middle being included in the selection or mask.

A faster option, however, would be to subtract everything except the middle balloon in one step. That’s what the intersect option makes possible. Using the intersect option, you select only the middle balloon, and that middle balloon becomes the only balloon that is selected or included in the mask.

What’s happening in the background is that the two selections or masks are being compared, and the final selection or mask will represent only the overlap (or intersection) between both of them. However, I think it is easier to think of it as an option to “subract everything but this”. In this example that would mean you are selecting the middle balloon, effectively saying “remove all balloons from the selection or mask except this one”.

Another way you could look at this is that the intersect option is the same as subtracting the opposite of what you’ve selected. In the example above, that means intersect is the same as creating a selection of the middle hot air balloon, inverting that selection or mask, and using that to subtract from the selection of all three hot air balloons.

Today’s Question: I’d like to rename my Lightroom Classic catalog. The option for renaming asks about renaming the parent folder. When would I want to do this?

Tim’s Quick Answer: You might want to rename the folder that contains your Lightroom Classic catalog just so the folder name is more clear to you. Just be sure to NOT rename the folder if you have photos stored within the same folder structure as the catalog.

More Detail: With a relatively recent update Lightroom Classic includes an option to rename a catalog. Simply make sure you have the catalog you want to rename open in Lightroom Classic and choose File > Rename Catalog from the menu. You can then enter a more meaningful name in the New Name field, or simply update the filename such as to remove the text along the lines of “-2-2-2-v13” that may have accumulated over the years from various updates to the catalog over time.

In the Rename Catalog dialog there is also a “Rename parent folder” checkbox. If you turn this checkbox on, the folder containing the catalog will be renamed to match the new base filename of the catalog. This can be convenient, since a meaningful name for the catalog probably represents a good name for the folder containing the catalog and related files.

However, if you have any photos stored within the same folder structure as the catalog that have also been imported into the catalog, renaming the parent folder will cause the photos and any related folders to appear as missing in Lightroom Classic.

So, if you’re not sure whether you have any photos stored in the folder structure along with the catalog, it is better to not rename the folder. If you’re certain there are no photos stored in that folder structure (and there’s really no reason for there to be), you can rename the catalog folder if you’d like. If you do have photos stored in the same folder structure, you can rename the catalog as above, but then rename the parent folder from within Lightroom Classic to avoid creating any missing photos or folders.

Today’s Question: When I try to assemble an HDR [high dynamic range] panorama in Lightroom Classic, it tells me that Deghost will not be applied. Is there a way to use the Deghost feature when creating an HDR panorama?

Tim’s Quick Answer: Yes, you can use Deghost for an HDR panorama, but you’ll need to merge the HDR frames first and then assemble those into a panorama.

More Detail: Lightroom Classic (and Camera Raw for non-Lightroom users!) can assemble high dynamic range (HDR) images and composite panoramas. Both applications can also combine the two techniques in a single process to create an HDR panorama.

However, when you assemble an HDR panorama the Auto-Align feature will automatically be applied (and can’t be turned off) and the Deghost feature is not available. If you want to use Deghost (or disable Auto-Align) you’ll need to assemble the HDR panorama in a two-step process.

The first step is to assemble each bracketed set if captures into an HDR image. During this process you can adjust the settings based on your preference, such as to leverage the Deghost feature. I recommend using the exact same settings for each bracketed set of images you’ll assemble into the panorama.

Once the HDR images have been assembled, you can select only the HDR images (they will be saved as Adobe DNG files) and then use the Photo > Photo Merge > Panorama command to create a panorama based on the HDR images. This will result in the final HDR panorama, requiring more steps than the fully automated approach but with more flexibility in terms of how the images are assembled.

Today’s Question: I have a photo where the People option for Distraction Removal in Lightroom Classic is not finding the people in the image and therefore can’t remove them. Is there a way to tell Lightroom Classic where the people are so they can be removed automatically?

Tim’s Quick Answer: Sort of. You can’t provide assistance to the Distraction Removal feature, but you can still remove the people by painting with the Remove tool, perhaps with the inclusion of generative AI. The same feature is available in Camera Raw, Lightroom Classic, and Lightroom.

More Detail: The options found under the Distraction Removal heading for Lightroom Classic, Camera Raw, and Lightroom are completely automatic. If the target subject (such as people with the People option) aren’t identified for a given image, then the feature simply won’t work with that image. Note that this feature is specifically looking for people that are distracting in the frame, so a person that appears as a key subject won’t be detected either.

However, you can get similar results by using the Remove tool, generally in conjunction with the generative AI feature for the best results.

In Lightroom Classic, for example, after choosing the Remove tool from the toolbar below the histogram on the right panel, make sure the Remove option (the first button) is selected for Mode. To get results consistent with what you can normally expect for the Distraction Removal feature turn on the “Use generative AI” checkbox. You can then paint over the distracting people in the photo, refine the mask you’ve painted as needed, and click the Remove button to apply the distraction removal.

While this manual approach isn’t as fast or convenient as the automatic option under Distraction Removal, it will generally provide you with similar (and generally very good) results for removing people from an image.

Today’s Question: I have an older iMac running Ventura (13.x), that cannot run a later version of MacOS. I have the Adobe Photography subscription, which includes Bridge, Photoshop and Lightroom. In your opinion do you think it will continue to run on my iMac? And do you know if an update to the mentioned software will break it? And if so, is it possible to turn off auto updates from Adobe?

Tim’s Quick Answer: I would not expect MacOS Ventura to be supported much longer for future updates to Adobe applications. However, you can disable automatic updates to provide more time before you would need to upgrade your computer by using older versions of Adobe applications.

More Detail: Backward compatibility is a particular challenge for those using a Macintosh computer. Older hardware is not supported by more recent versions of the MacOS operating system, and Adobe applications (among others) tend not to support older operating system versions.

For Macintosh users the current system requirements only support operating systems as old as MacOS Ventura (v13). At some point in the relatively near future, I expect that to change so that MacOS Sonoma (v14) is the oldest operating system version that is supported. Since your computer can’t be updated, that prevents you from updating to the latest versions of Adobe applications, once they require MacOS Sonoma or later.

To buy yourself time before you need to replace your computer, you can simply stop updating Adobe applications once the system requirements no longer support MacOS Ventura. To disable automatic updates, choose “Apps” from the toolbar along the left edge of the Creative Cloud application (where you would install applications or updates). Toward the top-center click “Manage auto-updates”. You can then turn off “Auto-update” to disable any automatic updates, or keep that option turned on and then turn off automatic updates for specific applications.

Today’s Question: I have been using Photoshop for over 20 years and early on decided to avoid using the denoise functionality because of potential loss of detail. However, recently I have been experimenting with this function and have been pleased with the results in many challenging situations, so I assume this functionality has been upgraded over time. However, I still am concerned about what the process does to the source file, as it seems to apply destructive edits. Am I correct?

Tim’s Quick Answer: No, none of the adjustments (including Denoise) in Camera Raw, Lightroom Classic, and Lightroom, will alter the original raw capture. And it is true that Denoise has gotten significantly better with recent updates.

More Detail: I suspect any concern about Denoise altering the original raw capture is the result that a recent change from Adobe enables Denoise to be applied without having to create a DNG file as part of the process. In effect, Denoise is now simply another of the many adjustments available in Camera Raw, Lightroom Classic, and Lightroom.

One of the key features of raw processing software is that it does not alter the original raw capture. Rather, the raw data is processed with the adjustment settings you’ve specified, to generate new pixels that would typically then result in a new image file. The raw capture remains unaltered. The adjustment settings are preserved in an XMP “sidecar” file. This can contribute to making it appear that the raw capture was modified, because if you open the raw capture again, you’ll see that all prior adjustments (including Denoise) are already in effect.

Rest assured that your raw capture remains unmodified. You could, for example, simply reset all adjustments to revert to the original image, or make a second copy of the raw capture (without the XMP file) and open that to start from the default settings.

Today’s Question: The size of the original raw photo (CR3 from a Canon R5) was approximately 45 megabytes. When I sent the image to Photoshop from Lightroom Classic to use Generative Fill for image cleanup, the resulting TIF file is now nearly 650 megabytes in size. Is this normal and, even if it is, do you have any suggestions that would keep resulting edits (when they become TIF’s via Photoshop) to a more “reasonable” size?

Tim’s Quick Answer: This significant increase in file size is mostly due to the use of Generative Fill in Photoshop without flattening the layers. In the absence of the use of Generative Fill in this case the resulting file would not have been anywhere near as large.

More Detail: A TIFF file will always have a considerably larger file size that a raw capture, though there are a number of factors that can dramatically increase the file size for a TIFF image.

To begin with, in most cases a raw capture only contains only one of the three RGB (red, green, blue) for each of the pixels in the final image. It is not until the raw capture is processed to create another image that the full pixel data is generated. At that time, the file will generally be at least three times larger than the raw capture based on 8-bit per channel mode. If the TIFF image was saved in the 16-bit per channel mode, that base file size increases to six times the original file size.

So, in the case of a 45MB raw capture, a TIFF saved in 8-bit per channel mode would be about 135MB in size. At 16-bits per channel that file size would increase to about 270MB.

However, the Generative Fill feature adds an additional layer with considerable data. This can lead to an image that is almost ten times larger than the original raw capture.

There are two basic strategies that can be used to reduce the file size of a TIFF or PSD image. One is to flatten layers once you’re completely confident that the image is completely finished and you don’t need to modify any of the existing layers. Of course, you always have the raw capture to go back to if you need to make changes, but this could still involve considerable work depending on what you had done in Photoshop.

The other thing you could do is convert the image to 8-bit per channel mode rather than 16-bit per channel mode. I only recommend considering this option if you are completely finished with adjustments and you have flattened all layers, because otherwise converting to 8-bit per channel can cause posterization (a loss of smooth gradations in the image).

Note that there is also compression available for TIFF files, which can help reduce the file size to some extent. This won’t make as much of a difference as the above options, but it is helpful. In Lightroom Classic you can go to the External Editing tab of the Preferences dialog and choose ZIP from the Compression popup. This will help reduce file size without any impact on image quality.

Today’s Question: When I import images into Lightroom Classic I use a user preset that includes Lightroom’s “auto” processing. I find that’s a good place to start my adjustments. I also often take bracketed exposures to create HDR [high dynamic range] images through Lightroom’s “Photo Merge” feature. Does the “auto” import processing affect the HDR creation?

Tim’s Quick Answer: Adjustments applied to bracketed exposures before merging to a high dynamic range (HDR) image won’t affect the creation of the underlying HDR image, but can affect the initial appearance of that image.

More Detail: It is not a problem to apply adjustments to the bracketed images before merging them into an HDR image in Lightroom Classic. Applying adjustments before merging will not affect the underlying HDR image that is assembled. However, many of the adjustments will carry through to the HDR image. But if you’re not happy with the results, you can always refine the adjustments after merging.

As a somewhat extreme example, let’s assume you converted a bracketed set of exposures to black and white (using the B&W treatment option in the Basic section) before merging them to HDR. The resulting HDR image will appear in black and white rather than color. However, you could then simply turn off the B&W treatment option and the HDR will magically appear in color again.

The issue is a little different with the tonal adjustments applied when you use the Auto adjustment, in that the basic tonal adjustments will not carry through to the HDR image. For example, if you shifted the exposure value for all the bracketed images, that would not cause any change in the HDR image when you merge the image. The HDR would be the same with or without the Exposure adjustment for the bracketed exposures.

Also keep in mind that you can enable the “Auto Settings” option in the HDR Merge Preview dialog, which is similar in concept to applying the Auto adjustment in the Develop module or on import via a preset. This will alter the settings based on an evaluation of the HDR image, but you can always refine the adjustment settings later with no impact on image quality.

Today’s Question: Can one make a collection set in Lightroom Classic after the fact? I have a large number of collections, and if I had been thinking ahead, I would have organized them into sets. Can I do that now?

Tim’s Quick Answer: Yes, you can create a new collection set after you created collections and then move existing collections into a collection set.

More Detail: Collections in Lightroom Classic can be organized into collection sets, similar to how a group of related folders can be placed into a common parent folder. While it is possible to add a collection to a collection set when the collection is created, you can also add collection sets after the fact.

To create a new collection set, click the plus (+) icon to the right of the Collections heading on the left panel in the Library module and choose “Create Collection Set” from the popup menu. In the dialog that appears, enter a meaningful name for the collection set in the Name field and click the Create button. The new collection set will then appear in the Collections section.

When you want to add an existing collection to a collection set, simply drag the collection onto the collection set. This will place the collection inside the collection set, and you can then collapse the collection set to hide the contents and streamline the display in the Collections section.

Note that you can also have multiple layers of nested collection sets. For example, you could create a collection set called “Projects” that contains collection sets for “Calendars”, “Books”, and “Presentations”. You could then put collections into their respective category of collection set, which in turn is inside another collection set. This can be especially helpful for photographers who create a particularly large number of collections for organizing their photos.

Today’s Question: What do they [Adobe] mean by “Export Negative Files” [with the Export as Catalog command in Lightroom Classic]?

Tim’s Quick Answer: The “Export Negative Files” checkbox in the “Export as Catalog” dialog really means “export copies of source photos”.

More Detail: In an earlier Ask Tim Grey post I addressed how the “Export as Catalog” command could be used to back up the Lightroom Classic catalog along with the photos it contains. This command can also be helpful when, for example, you have been working with a traveling catalog on a laptop and want to migrate that catalog to your desktop computer to merge with the primary catalog.

The general process involves creating a new catalog that contains all the information about the photos you’re exporting, which could include all photos in the source catalog or just a subset, depending on the purpose. In addition, you would generally want to make copies of the photos to go along with the new catalog, so that you had everything you needed to continue managing the photos reflected in the new catalog all in one place.

If you want to include copies of the photos along with the new catalog, you need to turn on the “Export Negative Files” checkbox. This name, I think it is fair to say, is wildly confusing.

My assumption—which I’ve never verified—has always been that someone at Adobe thought they were being clever. The name “Lightroom” is obviously a variation on the darkroom that was a key aspect of film photography. So, I have always assumed that the term “negative” in “Export Negative Files” referred to the negatives that are the source of prints made in the wet darkroom. Ignoring the fact that “negative” is a term that essentially excludes slide film, it is also confusing to use this term in the context of managing digital photos.

Regardless of the etymology or intent, I think the use of “negative” in the context of the Export as Catalog command is confusing. I’m frankly a bit surprised that with Lightroom having been around for more than 18 years Adobe hasn’t updated the checkbox to have a more meaningful name.

If you’re interested in the original post about using the Export as Catalog command to back up the catalog and photos, you can find it on the Ask Tim Grey blog here:

https://asktimgrey.com/2025/09/10/full-backup-of-catalog-and-photos/