Ask Tim Grey

Today’s Question: As a follow up to editing photos when the source drive is not connected, how does Lightroom deal with it when write to XMP sidecar files is enabled? Does it wait until the drive is connected and write them then? Automatically?

Tim’s Quick Answer: Yes, as soon as the source files are available again, Lightroom Classic will automatically save any updates you had made while the files were offline as long as you have turned on the option for these updates to be applied automatically.

More Detail: One of the advantages of the catalog in Lightroom Classic is that you can browse your photos (as long as previews had been built) and apply metadata updates even if the source files aren’t currently available. For example, if you store your photos on an external hard drive that isn’t connected to the computer, you can still review those photos, assign star ratings, add keywords, and more. If you build Smart Previews you can even apply adjustments in the Develop module.

If you turn on the “Automatically write changes into XMP” checkbox on the Metadata tab of the Catalog Settings dialog, Lightroom Classic will also save standard metadata updates to the source files. If you have applied updates while the source files were offline, Lightroom Classic will automatically start saving any metadata updates to the XMP sidecar files for raw captures (or to the files themselves for other image formats) once the files are available again.

If you’re not feeling confident that the updates were saved to the source files, or if you haven’t turned on the “Automatically write changes into XMP” checkbox, you can also manually save metadata updates to the source files. Simply go to the Library module and select the photos you want to update, then choose Metadata > Save Metadata to Files from the menu.

Today’s Question: Is there a way to batch process several images for an HDR [high dynamic range] merge in Lightroom Classic?

Tim’s Quick Answer: Yes, you can batch process bracketed photos into high dynamic range (HDR) images by first stacking the images and collapsing the stacks.

More Detail: I think it is well known that you can assemble HDR images in Lightroom Classic. However, it is a bit of a “hidden feature” that you can process HDR images in batch as well. This can obviously provide some workflow efficiency, and can also be very helpful for being better able to review the images to find your favorites without having to try to interpret the original bracketed exposures.

Batch processing for HDR is only supported for stacks of images, so you’ll first need to group the bracketed exposures into stacks. You can do this manually by selecting the images for a stack, right-clicking on one of the selected images, and choosing Stacking > Group into Stack from the popup menu. You can also potentially stack the images automatically by using the menu command Photo > Stacking > Auto-Stack by Capture Time.

You also need to collapse the stacks, which can be done by choosing Photo > Stacking > Collapse All Stacks from the menu. Then select the stacsk, and initiate the batch HDR processing by choosing Photo > Photo Merge > HDR from the menu.

Note that the processing for the selected stacks will be handled automatically, with no option to adjust the settings for the batch processing. The Auto-Align feature will be enabled for all images, but the Deghost option will be disabled. The Adobe DNG files for the assembled HDR images will be added to the top of each stack that was processed.

And for those wondering, in anticipation of a follow-up question, yes, you can perform the same batch processing for panoramic images using the exact same steps above in conjunction with the menu command Photo > Photo Merge > Panorama.

Today’s Question: How do you select a color space in Lightroom Classic?

Tim’s Quick Answer: In Lightroom Classic you can only select a color profile when sending an image outside of Lightroom Classic, such as when exporting or editing in Photoshop.

More Detail: Today’s question was a follow-up to the question last week about the color space setting in Camera Raw for those editing photos in Photoshop. The equivalent in Lightroom Classic would be to choose a color profile for images being exported or edited in another application such as Photoshop.

In Photoshop you can select a working space profile in the Color Settings dialog, but this isn’t an option in Lightroom Classic. Rather, Lightroom Classic always uses the ProPhoto RGB color space for rendering images in the Develop module. The Adobe RGB and sRGB color spaces are used in other modules, depending on the focus of the task. You can’t change this behavior, as it is internal to Lightroom Classic.

You can, however, select a profile for images being exported from Lightroom Classic. You can choose the color space you want to use for images being sent to Photoshop on the External Editing tab of the Preferences dialog. There you’ll find a Color Space popup under the “Edit in Adobe Photoshop” heading. There is also a Color Space popup available for configuring other external editors under the “Additional External Editor” heading.

When exporting a copy of an image from Lightroom Classic you can also select the color profile you want to convert the image to. For example, sRGB is a good profile to use for images that will be shared digitally, and Adobe RGB is a good profile to use for images that will be printed after export. The Color Space popup in the File Settings section of the Export dialog is where you can select this profile, as long as you have chosen an image format option other than “Original” or “DNG” from the Image Format popup.

Today’s Question: Sometimes when I open an image in Camera Raw I see a warning symbol with an exclamation point at the bottom-right of the image. I understand that Camera Raw is trying to tell me there’s some sort of problem, but what is it?

Tim’s Quick Answer: That warning icon indicates that the image is set not set to the most recent process version, meaning in effect it is still being adjusted based on an older version of Camera Raw. You can update to the latest process version by clicking the symbol, but be aware that the appearance of the image may change to some degree as a result.

More Detail: With Camera Raw (as will as Lightroom and Lightroom Classic) there are process versions that basically relate to a specific version of the various adjustments available. With certain updates to these applications over the years, the image processing has been updated or expanded, resulting in a new process version.

If you open an image in Camera Raw that has never been opened before, it will default to the current process version and you’ll have access to all the latest adjustments. If you had previously processed the image with an older version of camera raw with an older process version, that older process version will be retained when you open the image with Camera Raw again. This is to ensure that the image is processed the same way and with the same appearance as when it was original optimized.

You can find the process version in the Calibration section of the Edit panel in Camera Raw. You can update the process version as needed by choosing the most recent (currently Version 6) from the Process popup. However, if you open an image that is set to an older process version you’ll also see a warning symbol of a triangle with an exclamation point in it at the bottom-right of the image preview area. You can also click that warning icon to update to the latest process version.

Because a process version relates to a different version of the adjustment engine for Camera Raw (or Lightroom or Lightroom Classic), changing the process version can cause the appearance of the image to change. In some cases that change can be somewhat significant. It is therefore important to pay attention to the image when updating the process version, and then to revisit the adjustments to get the image looking its best again. By updating the process version, however, you’ll also ensure you have access to all the latest updates and adjustments for processing your photo.

Today’s Question: The other day I took a snapshot with my iPhone that I wanted to share. The photo was too dark, so I decided to brighten it a bit and add some Clarity in Lightroom Classic. I exported the photo to my hard drive using Image Format: Original. When I attached the photo to the email, it was still too dark, not at all as it appeared in Lightroom Classic. Eventually, I tried exporting it with Image Format set to JPEG. The export worked fine. What’s going on?

Tim’s Quick Answer: When you select the “Original” option for the Image Format setting when exporting a photo from Lightroom Classic, you are exporting a copy of the original file without any adjustments. If you want to have the adjustments included in the exported file, you’ll need to choose a specific image format from the popup, not the “Original” option.

More Detail: Admittedly, it can be a little confusing when you export an image from Lightroom Classic and the adjustments are not included. But this is only an issue if you choose the “Original” option from the Image Format popup in the File Settings section of the Export dialog. That option exports a copy of the original image as it was captured, with no adjustments or other metadata updates applied.

If you want to include adjustments in the exported image, you’ll need to choose a specific file format other than “Original”. That is true even if you are exporting an image that was captured as a JPEG and you want the exported copy to be a JPEG. In this case if you choose “Original” the adjustments from the Develop module will not be included in the exported file, but if you choose “JPEG” from the Image Format popup the exported image will include the adjustments. This is true even though in both cases you would be exporting a JPEG image in this example.

So, the “Original” option is for exporting a copy of the image as it came from the camera, while choosing a specific file format will create a copy that does include your adjustments from the Develop module.

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.