Ask Tim Grey

Today’s Question: I understand that a higher bit depth is a good thing for an image, but why do you say it is especially important when working in the ProPhoto RGB color space or when working with a black and white image?

Tim’s Quick Answer: Working in 16-bit mode is important with the ProPhoto RGB color space because of the very large size of this color space. It is important with black and white images because such a small number of shades of gray are available with 8-bit per channel mode.

More Detail: The bit depth is particularly important for black and white (grayscale) images because there are a relatively small number of shades of gray available for monochromatic images to begin with. The 8-bit per channel mode only provides a maximum of 256 shades of gray ranging from black to white, while 16-bit per channel mode provides up 65,536 shades of gray. The result is that with black and white images it is extremely likely to see posterization (a loss of smooth gradations) when adjustments are applied to a black and white image in the 8-bit per channel mode.

The numbers are a bit more dramatic for color images, though the numbers can also be a little misleading. An 8-bit per channel RGB image can contain up to almost 16.8 million colors (16,777,216 to be exact). A 16-bit per channel image can contain over 281 trillion colors (281,474,976,710,656 for those keeping score). While there’s a huge difference between those numbers, in general 8-bit per channel mode works perfectly well for color images. However, with the ProPhoto RGB color space I recommend being sure to work in the 16-bit per channel mode.

The reason 16-bit per channel mode is more important with the ProPhoto RGB color space is that this color space is particularly large. That means it covers an extreme range of color values, to the point that it actually includes colors that are well beyond the visible spectrum.

Due to the large size of the ProPhoto RGB color space, with the 8-bit per channel mode the distance between neighboring colors is relatively large. That can lead to a relatively high risk of posterization, or the loss of smooth gradations of colors, when strong adjustments are applied.

I consider it a good practice to always work in the 16-bit per channel mode when editing images. But as outlined above, that is especially true when it comes to working with images in the ProPhoto RGB color space or when working with monochrome images.

Today’s Question: When opening files in Camera Raw, they’ve always opened with a profile of ColorMatch RGB (8 bit). These days they’re opening with as Display P3 (16 bit). I’m not aware of having changed any settings. Any idea what’s going on here?

Tim’s Quick Answer: I suspect this change may have been caused by a software update, and you can change the default profile setting in Camera Raw Preferences. I also suggest keeping the bit depth at 16-bits per channel.

More Detail: I also experienced this change in the default profile in Camera Raw, so I suspect this is a widespread issue. My guess is that it resulted from either a software update from Adobe or an update in the macOS operating system, though I’m not sure which since I had updated both prior to seeing the change in Camera Raw.

The current profile setting is shown in the workflow settings summary at the bottom-center of the Camera Raw interface. That summary is actually a link, which you can click to bring up the Camera Raw Preferences dialog with the Workflow tab selected. You can also get to the Preferences dialog by clicking the gear icon at the top-right of the Camera Raw window.

On the Workflow tab of the Camera Raw settings dialog you can choose the profile you want to use from the Space popup in the Color Space section. I generally recommend the ProPhoto RGB color space because it is among the largest color space profile options. Adobe RGB is also a good general-purpose option, and the sRGB color space is good for images that will only be displayed digitally and not printed.

I also recommend using the 16 bits per channel option for the Depth setting, which provides significantly more color values than 8 bits per channel. This is especially important when using the ProPhoto RGB color space, or when working with black and white images.

Once you’ve updated these settings, you can click the OK button to save the changes. Those settings will become the new default settings for images that have not yet been processed in Camera Raw. Note, however, that if you open an image that had previously been processed with camera raw, the settings active at that time—including the color profile—will remain as the settings for the image when opened again.

Today’s Question: In Lightroom Classic, what is the best way to move images in your catalog from one folder to another or from one hard drive to another? I know you’ve said to do it in Lightroom, but I don’t see how from either the import dialogue or dragging. Most of my images are on one external drive, but some are saved on my computer’s hard drive. I want to get them all on the external.

Tim’s Quick Answer: You can move folders or photos by dragging a folder within the Folders list on the left panel in the Library module, or move photos by selecting them and dragging the thumbnails to a different folder. You can also create a new folder if needed, including creating a new folder on a hard drive that isn’t yet being managed by Lightroom Classic.

More Detail: If you want to move folders or photos that are being managed by Lightroom Classic, it is important to move them within Lightroom Classic, not through the operating system or other software. Otherwise, Lightroom Classic will lose track of the location of the photos, so that folders and photos will appear as missing.

Instead, you can simply drag-and-drop photos or folders within Lightroom Classic. Simply drag selected photos or folders to a different location within the Folders section of the left panel in the Library module. If you need to drag the selected items to a level higher than the folders that are visible, such as a parent folder, you can right-click on a top-level folder and choose “Show Parent Folder” from the popup menu.

If you need to create a new destination folder, you can click the plus symbol to the right of the Folders heading and choose “Add Folder”. You can then navigate to the location where you want to create a new folder (including on a new hard drive that isn’t yet being used in Lightroom Classic) and create a new folder. That folder will then appear in the Folders list (even if it is on a hard drive that wasn’t previously being managed by Lightroom Classic) so you can drag folders or photos to that new folder.

In other words, you can work within Lightroom Classic in much the same way as you could work in your operating system in terms of creating folders, moving folders and photos, and even renaming folders and photos. The key is to perform that work within Lightroom Classic so the catalog stays up to date with the changes on your hard drives.

Today’s Question: When I choose to build previews [in Lightroom Classic] and have XMP sidecars are the previews in the XMP?

Tim’s Quick Answer: No, previews are stored alongside the catalog in Lightroom Classic. The XMP sidecar files only contain metadata updates.

More Detail: If you save metadata to raw captures in Lightroom Classic, metadata updates are saved to XMP sidecar files in addition to being saved in the catalog. You can save metadata to selected images manually by choosing Metadata > Save Metadata to File from the menu. You can also enable the automatic saving of metadata to the source files by turning on the “Automatically write changes into XMP” checkbox on the Metadata tab of the Catalog Settings dialog.

However, saving metadata to the source files does not cause previews to be saved to those files. Previews are only saved alongside the catalog, in a previews file in the same folder as the primary catalog file. This enables you to view previews of your images whenever you open the catalog, even if the source image files are not currently available, such as when an external hard drive containing images is disconnected from the computer.

Note that when you back up the Lightroom Classic catalog, the previews file is not backed up. That means that if you needed to restore from a backup because the catalog had been lost or corrupted, you may need to rebuild all previews again unless you had also backed up the previews file separate from the Lightroom Classic catalog backup.

Today’s Question: You mentioned that Lightroom Classic can show previews of photos that are on a hard drive not currently connected to the computer, as long as previews had already been created. I’m not seeing previews for many photos when my external drive is disconnected, so how can I get Lightroom Classic to build previews for all photos?

Tim’s Quick Answer: If you need to build previews for all images in your Lightroom Classic catalog you can select all images from the All Photographs collection with no filter set, and then from the menu choose Library > Previews > Build Standard-Sized Previews.

More Detail: Lightroom Classic will build standard previews as needed, meaning if you are browsing photos that don’t yet have standard previews and the source images are available, Lightroom Classic will build the previews. There’s also an option to build previews as part of the process of importing new photos, which can be helpful in terms of ensuring you have previews available for offline viewing.

Once previews are built for images, you can use those previews as the basis of viewing your photos even if the source files aren’t available, such as when an external hard drive containing photos isn’t connected to the computer.

If you find that previews are missing for some (or many) of your photos, you can build those previews on demand. Start by selecting the “All Photographs” collection in the Catalog section of the left panel in the Library module. Then go to the grid view display and make sure the Library Filter bar is displayed above the thumbnails, choosing View > Show Filter Bar from the menu if the bar isn’t shown. Then choose “None” to ensure no filter is set, so you’re seeing all images.

You can then choose Edit > Select All from the menu to select all photos, which in this case would mean all photos in your entire catalog. Then choose Library > Previews > Build Standard-Sized Previews from the menu, and Lightroom Classic will get to work building previews for all selected photos (as long as the photos are currently available).

The process of building previews could take quite a long time (hours or potentially days) depending on how many photos are in your catalog, how many of them don’t currently have previews, and the overall performance specifications of your computer. Once those previews are generated, however, you’ll be able to browse all photos even if the hard drive the photos are stored on isn’t connected to your computer.

Today’s Question: In Lightroom Classic, the only issue with having photos stored on two drives is that you’ll have two hard drives (and therefore two sets of folders) listed in the Folders list on the left panel in the Library module. Right now, if my [single] drive with photos is disconnected from the computer, Lightroom Classic tells me so. If I had photos split between two drives, then as long as one of the two drives is plugged in, Lightroom Classic would recognize which one and be happy?

Tim’s Quick Answer: When photos are stored on more than one hard drive, Lightroom Classic will show as available the folders and photos on a drive that is connected, and folders and photos will show as missing for a drive that is disconnected.

More Detail: One of the advantages of the catalog used by Lightroom Classic to manage information about your photos is that you can still view and update metadata your photos even when the source files aren’t available. So, for example, if you disconnect an external hard drive that contains photos being managed by Lightroom Classic, you can still view the photos (as long as previews had been generated) and update the metadata for the photos even though they are not currently available.

The situation isn’t really any different if you have photos stored across more than one hard drive. In this scenario you would have a section for each hard drive in the Folders list on the left panel in the Library module. If a hard drive is disconnected, the heading for that drive will be dimmed, and the folders and photos on that drive will show as missing. If a hard drive is connected, the heading will not be dimmed, and the folders and photos won’t appear as missing.

So, if your photos are stored on two different hard drives, but only one of them is connected to your computer, the connected drive will be represented by folders that are available, and the disconnected drive will be represented by folders that show missing. In other words, the section for each hard drive in the Folders list operates independently, so it is absolutely possible to work with photos from just one drive at a time, for example, if you don’t want to have multiple hard drives connected to your computer at the same time.

Today’s Question: Should I rename my Lightroom Classic catalog before or after upgrading to Lightroom Classic 14? Or does it matter?

Tim’s Quick Answer: If you’re going to rename your Lightroom Classic catalog I definitely recommend doing so after you upgrade to Lightroom Classic version 14, not before.

More Detail: Prior to version 14 of Lightroom Classic, renaming the catalog files was simple in concept, but involved considerable risk that one or more files wouldn’t be renamed correctly. With the update to version 14, the new Rename Catalog command makes it remarkably easy to rename the catalog without risk.

Once you’ve upgraded to version 14, you can rename your catalog (including all related files) by choosing File > Rename Catalog from the menu. In the dialog that appears, you can enter a new name for your catalog. If you want to rename the folder that contains your catalog files to the same name, you can turn on the “Rename parent folder” checkbox. Click the Rename button to apply the change.

By comparison, before the Rename Command was added you would need to rename all files related to your catalog in the same way, while retaining the “extra” text for some of the file such as the Previews and Smart Previews files. While this was reasonably straightforward, it involved renaming multiple files and required a bit of attention to detail. The new command makes it remarkably easy. I just wish Adobe had added the command a long time ago!

Today’s Question: What can we do about Camera Raw having features that aren’t in Lightroom Classic, at least for now?

Tim’s Quick Answer: You could use Photoshop as a conduit to get access to the features that are now available in Camera Raw but not in Lightroom Classic.

More Detail: The latest updates to Adobe applications represent a bit of an unusual (though not unprecedented issue). For now, there is not parity between the applications, with a few features in Camera Raw that aren’t available in any version of Lightroom.

The features in question are updates to the “Enhance” features (which includes Denoise, for example), a Generative Expand feature for cropping, and a new Adobe Adaptive profile.

There are a couple of things you could do to gain access to these features if you’re using Lightroom Classic. One is to leverage Camera Raw by using a Smart Object. Start by selecting a raw capture in Lightroom Classic, and then from the menu choose Photo > Edit In > Open as Smart Object in Photoshop. When the image opens, the image will be represented as a Smart Object on the Layers panel. Double-click the thumbnail for that Smart Object and the image will open in Camera Raw. From there you can leverage all the new features that are in Camera Raw but not Lightroom Classic. Note that you need to use this Smart Object workflow to accomplish this, rather than using Camera Raw from the Filter menu.

Note that to take advantage of the updated Enhance features (such as Denoise), you’ll need to turn on the “New AI Features and Settings Panel” on the Technology Previews tab of the Camera Raw Preferences dialog.

Of course, the approach above will cause a new file to be created when you save the result, as a TIFF or PSD depending on the setting you have selected in Preferences for External Editing in Lightroom Classic. In other words, you’re not really getting a benefit in terms of using Photoshop to access Camera Raw rather than just generating a DNG file with the Denoise feature in Lightroom Classic.

The approach above is a good way to get access to the Adobe Adaptive profile if you have found that to be useful. I don’t personally find the new profile to be helpful enough that I would go to this much effort to get access to it.

It is also worth noting that you could simply edit an image normally in Photoshop from Lightroom Classic to make use of the Generative Expand feature for the normal Crop tool in Photoshop, without having to use the Camera Raw workflow outlined above.

Having said all that, the point is that if you want to gain access to the new features in Camera Raw that aren’t currently in Lightroom Classic, you can do so by leveraging a Smart Object in Photoshop.

Today’s Question: You mentioned a “layer group” in passing in your answer [in Wednesday’s Ask Tim Grey eNewsletter] in the context of targeted adjustments in Photoshop. Can you explain how a layer group can be involved in a targeted adjustment?

Tim’s Quick Answer: A layer group in Photoshop enables you to (among other things) use a single layer mask to constrain the effect of multiple adjustment layers, so that if the mask needs to be refined, you only have to change the single layer mask associated with the layer group, rather than fixing the layer mask for multiple individual adjustment layers.

More Detail: Layer groups in Photoshop enable you to group various layers together, which can be helpful in terms of keeping the Layers panel more organized. However, I find layer groups to be especially helpful when it comes to applying targeted adjustments.

More often than not, I find that if I want to apply an adjustment to a specific area of an image in Photoshop, I actually want to apply more than one type of adjustment to the same area.

Let’s assume, for example, that I want to modify the appearance of the sky in a photo using several different adjustments. I could create a selection of the sky and add an adjustment layer, then reload the sky selection and add another adjustment layer, and repeat this process for as many adjustments as I’d like to apply to the sky.

However, if I then discovered that my original selection of the sky wasn’t quite perfect, I would need to correct the layer mask for all the adjustment layers that were based on the same sky selection. You can streamline this process by using a layer group instead.

To get started, you could select the sky. Then add a layer group by clicking on the button with a folder icon at the bottom of the Layers panel. With the selection active and the layer group selected on the Layers panel, click the “Add Layer Mask” button (the circle inside a rectangle icon) at the bottom of the Layers panel. You now have a layer group that is constrained by the mask based on the sky selection.

At that point you can add as many adjustment layers to the layer group as you’d like, and all the adjustments will only affect the area of the image defined by the layer mask attached to the layer group. If you later discover the layer mask wasn’t quite perfect, you can simply modify the single layer mask for the layer group, without having to update a layer mask for multiple adjustment layers.

Today’s Question: Following up your discussion on collections [in Lightroom Classic], if I pull a selection of pictures from a variety of drivers and folders, is there a way to create a single directory of the images or a copy to provide them to someone else?

Tim’s Quick Answer: In this scenario I would suggest exporting copies of the photos from the collection to a new folder. If needed that folder could also be added to the current catalog.

More Detail: One of the advantages of collections in Lightroom Classic is that they can be used to group photos together from a variety of different storage locations. For example, you can group photos from a number of different folders into a single collection, such as to use the images in a photo project.

If you want to share copies of those photos with someone else, one option would be to export copies of the images. You could select all the photos in the collection, for example, and then click the Export button at the bottom of the left panel. In the export dialog you could then configure the settings for how you want the copies of the photos generated, such as the file type, image resolution, and more.

Note that there is a checkbox in Export Location section of the Export dialog labeled “Add to This Catalog”. You can turn that checkbox on if you want the copies of the photos you’ve exported to be added to the catalog so you can manage them directly from there. In general, however, I don’t recommend using this option because it can lead to confusion between these copies and the original images they were based on.

As a reminder, it is also possible to create a web gallery based on a collection, and to make that gallery public so you can share the images with others. You can get more info on that process in an earlier Ask Tim Grey article here:

https://asktimgrey.com/2024/02/12/public-sharing-of-collections/