Ask Tim Grey

Today’s Question: In what situations would you convert from 16-bit to 8-bit?

Tim’s Quick Answer: Only when necessary. I recommend keeping your primary image file in 16-bit per channel mode, and only converting to 8-bit per channel when creating an image for sharing, such as when saving a JPEG derivative image to share online.

More Detail: When you process a raw capture, such as with Camera Raw in Photoshop, I recommend converting to a 16-bit per channel image rather than 8-bit per channel to maximize potential detail and fidelity, and to minimize the risk of any posterization (the loss of smooth gradations of tone and color). I only recommend converting to 8-bit per channel mode when it is necessary, such as when saving a derivative image in a format such as JPEG that doesn’t support (or require) a higher bit depth.

If you’re completely finished applying adjustments to an image that had been saved in the 16-bit per channel mode, and you want to reduce the bit depth to reduce overall file size, the risks are not too great as long as you only do so for a color (not black and white) image and you make sure to flatten the image first (assuming the use of layers in Photoshop).

For black and white images, I would never convert the master image file to 8-bit per channel because doing so carries considerable risk of posterization in the image, leading to potential banding and other problematic visual artifacts.

But overall, I recommend keeping the master image in the 16-bit per channel mode, and only using 8-bit per channel mode for derivative images created for sharing. Even in those cases, it isn’t generally necessary to use the explicit step of converting to 8-bit per channel mode, such as by using the Image > Mode > 8 Bits/Channel command in Photoshop. For example in Photoshop you can simply use the “Save a Copy” command to save as a JPEG in 8-bit per channel mode because 16-bit per channel is not supported in that case.

Today’s Question: I have the dreaded “corrupted catalog” message [in Lightroom Classic] and have looked online at how to fix this. I am reluctant to try to fix this issue with so little knowledge of how the catalogs work. I fear causing more issues.

Tim’s Quick Answer: You can generally recover a corrupted catalog using tools built into Lightroom Classic. Failing that, you can recover from a catalog backup.

More Detail: There are two messages you may see if the Lightroom Classic catalog is corrupted. If you are presented with the dialog that includes the “Repair Catalog” button, click that button to see if Lightroom Classic is able to resolve the issue for you.

If you don’t see that button, you can launch Lightroom Classic while holding the Alt key on Windows or the Option key on Macintosh, which will bring up the Select Catalog dialog. Choose the applicable catalog from the list within the dialog and turn on the “Test integrity of this catalog” checkbox at the bottom-right of the list. Then click the Open dialog.

If neither of the above provide a solution, your best option is to recover from a recent catalog backup. By default those backups are stored in a “Backups” folder in the same folder as the catalog files. The backup will be a ZIP file that you can extract the catalog files from. Then open the catalog by double-clicking the file with the .lrcat filename extension.

Another option that may work is to create a new catalog and then use the “Import from Another Catalog” command to import the corrupted catalog into the new catalog.

Worst case, you could simply create a new catalog and import all existing photos using the Add option at the top-center of the Import dialog, making sure that you don’t apply any changes such as a metadata preset or Develop preset during that import. As long as you had previously enabled the option to automatically save metadata to the source files, this would preserve key metadata. However, in this case you would lose Lightroom-specific metadata such as collections, virtual copies, and history.

Today’s Question: Why is 8-bit a bigger problem for black and white images compared to color?

Tim’s Quick Answer: Put simply, for a black and white image there are very few shades of gray available in 8-bit per channel mode compared to a color image. This leads to a very high risk of posterization (a loss of smooth gradations of tone) especially with relatively strong adjustments.

More Detail: The bit depth for an image refers to the total number of tonal or color values available. A higher bit depth translates to more tonal or color values available, which helps ensure smoother gradations of tone and color in the image, even with relatively strong adjustments.

When working in 16-bit per channel mode there are a tremendous number of tonal or color values available. For a black and white image, that provides a total of 65,536 shades of gray from black all the way to white. For a color image the number is over 261 trillion color and tonal values.

For a black and white image there is only one channel rather than the three channels for an RGB image, which greatly impacts the number of tonal values available. In 8-bit per channel mode a color image can consist of up to almost 16.8 million color and tonal values. That’s nowhere near the huge number for a 16-bit per channel color image, but it is enough to provide smooth gradations unless extreme adjustments are applied.

For black and white images in 8-bit per channel mode there are only 256 shades of gray available. This creates a very real challenge for avoiding posterization even with relatively moderate adjustments. A very common example is a loss of smooth gradation in the sky, where banding can result even with minor adjustments. This takes on the appearance of something like a black and white rainbow, with bands of different shades of gray rather than smooth gradations across the sky.

So, while I always recommend working with images in the 16-bit per channel mode to maximize image quality especially in the context of avoiding posterization, this is especially important for black and white images because they are so much more limited in terms of the number of tonal values available.

Today’s Question: Do we need to be careful to only switch to 8-bit as a last step in editing [in Photoshop]?

Tim’s Quick Answer: In general, I recommend only converting to 8-bit per channel (rather than 16-bit) with a copy of the original image and after flattening that image.

More Detail: I strongly recommend leveraging 16-bit per channel processing for your images in Photoshop, rather than 8-bit per channel. This ensures the maximum available tonal and color values for the image. If adjustments are applied to an 8-bit per channel image there is a risk of posterization, or the loss of smooth gradations of tone and color. This is a particular concern for black and white images.

So, when processing a raw capture and opening it in Photoshop, I recommend keeping it in the 16-bit per channel mode. This is handled via the Workflow Settings in Camera Raw or the External Editing Preferences in Lightroom Classic. Save the image with all layers intact as a 16-bit per channel image as a TIFF or PSD file.

When you want to create an 8-bit per channel image, either export a copy with the desired settings, or create a duplicate within Photoshop. In the latter case you can choose Image > Duplicate Image from the menu, turning on the “Duplicate Merged Layers Only” checkbox so the duplicate will be flattened. This is very important to ensure the conversion to 8-bit per channel mode occurs after adjustments have been applied to the pixel data.

You can then convert the derivative image to 8-bit per channel mode by choosing Image > Mode > 8 Bits/Channel from the menu. You can then perform any other tasks, such as to resize to different pixel dimensions, and then saved the resulting derivative image in the desired file format.

Today’s Question: I have a photo where the sky is washed out (but not blown out) due to high overcast clouds and relatively bright lighting. I think this was somewhat exacerbated by the foreground being boats on the ocean, with a lot of light reflecting off the water. What would you recommend for adding some color or detail to the sky using Lightroom Classic?

Tim’s Quick Answer: In this type of situation, I recommend using a mask in Lightroom Classic, using the Color control to add a tint to the sky, and possibly reducing the value for Exposure and refining other adjustments as needed.

More Detail: There are a variety of things you could do to deal with a washed-out sky, including completely replacing the sky using another photo by creating a composite image in Photoshop. However, as long as the sky isn’t completely blown out, you can generally add some color and possibly darken or add contrast as needed. This would involve adding a mask so the adjustment only affects the sky.

In many cases you could obviously use the Select Sky mask option so the adjustment would only affect the sky. However, in many cases, especially with a relatively straight horizon, using the Linear Gradient option works very well. This enables you, for example, to have the adjustment taper off toward the horizon for a more natural look.

Once you’ve added either a Sky or Linear Gradient mask, you can apply the targeted adjustments. I recommend starting with the Color adjustment, which is often missed as it isn’t especially conspicuous. By default, the color swatch will appear as a white rectangle with a black “X” on it. Click that swatch to bring up the color picker, and click within the gradient to select a good shade of cyan or blue for the sky. Click the “X” at the top-left of the color picker to close it.

You can then apply other adjustments as needed. Often a slight reduction in the Exposure value will help, but you may also want to enhance contrast such as by increasing the value for Clarity or by adjusting the other tonal value adjustments such as Highlights, Shadows, Whites, and Blacks.

As needed, you can go back and forth between refining the layer mask and fine-tuning the adjustment settings until you are happy with the result. For example, if you used a linear gradient for the mask, you can reposition or adjust the size of the transition based on the adjustment you’ve applied, or you can modify the adjustments to better match the area being affected based on the mask.

Today’s Question: Once I’ve identified the people who appear in photos using the People view [in Lightroom Classic], is there a quick way to locate photos of a specific person without having to switch to the People view to find them?

Tim’s Quick Answer: Yes, you can simply filter the Keyword List to only show keywords that are identified as people, and then click the arrow associated with a name on the Keyword list to filter the photos to only those containing the keyword for the applicable person.

More Detail: When you identify a person in the People view, the keyword assigned to the image as part of that process is identified as a Person keyword. This is indicated by the fact that the Person checkbox will be turned on, which you can review by right-clicking on the applicable keyword on the Keyword List and choosing “Edit Keyword Tag” from the popup menu.

At the top of the keyword list there is a filter option for viewing only People keywords, which is easy to miss because it is hidden from view by default. You can expand the filter option by clicking the triangle icon to the right of the search field at the top of the Keyword List. That will reveal several options, including People. Click that label to filter the Keyword List to show only those that have the Person checkbox turned on.

Once you’ve filtered the Keyword List and located the name of the person you want to view images for, you can hover your mouse over the keyword for that person’s name and click the right-pointing arrow icon to the right of the keyword. This will set a filter so that all photos with the selected keyword will be displayed, based on your entire Lightroom Classic catalog.

Today’s Question: I upgraded to the latest Lightroom Classic and now the icons which indicated crop and adjustments are no longer at the bottom of the photos. I use this to keep track of my edits. Do you have any ideas why this is happening?

Tim’s Quick Answer: You can enable the badges you’re referring to in the Library View Options dialog for the grid view or in the Preferences dialog for the thumbnail filmstrip on the bottom panel.

More Detail: The small icons that appear at the bottom-right corner of thumbnails for some images are referred to as badges. They indicate the status of various features, such as whether an image has been cropped or whether adjustments have been applied in the Develop module, among others.

I haven’t seen any issue with an upgrade to Lightroom Classic causing these badges to be disabled, but it is easy to enable them again regardless.

For the grid view in the main image preview area, go to the menu and choose View > View Options. Go to the Grid View tab, and make sure the “Show Grid Extras” checkbox is turned on. Then also make sure that the “Thumbnail Badges” checkbox in the Cell Icons section is turned on. Then close the dialog, and you’ll have the thumbnail badges again in the grid view.

For the thumbnails on the filmstrip on the bottom panel, go to the Edit menu on Windows or the Lightroom Classic menu on Macintosh and choose “Preferences”. Go to the Interface tab and turn on the “Show badges” checkbox in the Filmstrip section. You can then close the dialog and you’ll have the badge icons restored on the thumbnails on the filmstrip.

If you’re curious about the meaning of these badge icons, by the way, there’s a post that explains them on the GreyLearning blog here:

https://greylearningblog.com/meaning-of-thumbnail-badge-icons-in-lightroom-classic/

Meaning of Thumbnail Badge Icons in Lightroom Classic

Today’s Question: I know you can batch rename photos in Lightroom Classic, but the process involved seems cumbersome when I only want to rename a single image, such as to add a bit of text to the end of the filename. Is there a simpler way to rename a single photo?

Tim’s Quick Answer: Yes! You can rename a single image in Lightroom Classic by updating the File Name field in the Library module.

More Detail: While the Rename Photos command can be tremendously helpful (and flexible) when it comes to renaming multiple selected images, I agree that it can be a little cumbersome for a situation where you want to make relatively minor changes to the filename for a single image. For example, you might want to append “-BW” to the end of a filename to indicate this is a black and white version of a color original.

Fortunately, you can very easily change the filename for a single selected image by editing the text in the File Name field in the Metadata section of the right panel in the Library module.

You can make any changes you’d like in that field, including completely changing the base filename if you want to. Just be sure not to edit the filename extension, which is includes the period after the base filename and the additional characters (typically three or four characters) that appear after the period. The filename change will take effect as soon as you change the focus to another field, such as by pressing the Tab or Enter/Return key on the keyboard or by clicking on another metadata field.

Today’s Question: My current 8TB hard drive is filling and I think it is time to prepare to increase my storage capacity. I have a 20TB internal drive that can be installed in my PC. Can I move my Lightroom Classic files and photos to the new 20TB drive and then delete them from the original 8TB drive?

Tim’s Quick Answer: You can most certainly move the Lightroom Classic catalog files and the photos to the larger storage without too much difficulty, though you do need to be careful with the process.

More Detail: There are several ways you could go about this task, but the approach I recommend is to copy the applicable files to the new destination, and then update the Lightroom Classic configuration to reflect the changes.

The first step would be to first quit Lightroom Classic and then copy the entire folder containing the catalog files to the new hard drive. After the copy is complete rename the folder on the original drive to reflect that it is now just a backup copy being held temporarily.

Then copy the entire photo storage to the new drive. If you don’t already have a top-level parent folder you might want to create it as part of this process, such as to create a “Photos” folder on the new drive and copy all folders for all photos into that drive. If the existing folder structure for folders was in a parent folder, I would rename that parent folder to indicate it is now a backup copy. If the drive is an external drive you can disconnect it, and if it is an internal drive you can change the drive letter (Windows) or the volume label (Macintosh). The point is to change the storage location so Lightroom Classic will not be able to find it where expected.

At this point you can open the catalog from the new hard drive location by double-clicking the file with the .lrcat filename extension in the catalog folder you copied to the new drive. Then go to the General tab of the Preferences dialog and set the catalog in the new location as the default catalog. This will ensure the catalog in the new location is always opened by default when you launch Lightroom Classic.

Initially all folders and photos will appear to be missing. But you can resolve that by reconnecting them to the new storage location. To do so, go to the top level folder above all existing folders, which might require you to right-click on the top folder on the list in the Folders section of the left panel in the Library module and choose “Find Missing Folder” from the popup. Then navigate to an open the related top level folder on the new drive, making sure that folder appears at the top-center of the dialog. Then click the Choose button to reconnect the top-level folder, which in turn will reconnect all subfolders and photos. At that point you can continue your normal workflow, and once you’ve backed everything up again you can delete the catalog folder and photos from their original location.

Today’s Question: How and where can you use Adobe Bridge to export a copy of the image?

Tim’s Quick Answer: You can export copies of images from Adobe Bridge in several ways, including by using the Export panel or the File > Export To command on the menu.

More Detail: The notion of exporting photos from Adobe Bridge may seem a little odd, since Bridge doesn’t use a catalog the way Lightroom Classic does. So you can think of this action as being more about creating a copy of selected photos in a way that enables you to apply changes, such as to change the pixel dimensions and save in a different file format than the original.

For example, you might want to create copies of photos to send via email or share online, where you want to reduce the pixel dimensions and save as a JPEG image.

One of the easiest ways to create this type of copy of one or more photos in Bridge is to select the photos and choose the File > Export To command followed by the desired option (such as Custom Export). You can also select the photos and drag them to the desired preset on the Export panel. If the panel isn’t visible you can choose Window > Export from the menu to enable it.

In either case the Export dialog will appear, where you can configure the settings for the derivative images you want to create and then click the Start Export button to initiate the process.

Another option is to use the Image Processor in Photoshop. You can send photos to Photoshop for this purpose by selecting the images in Bridge and then choosing Tools > Photoshop > Image Processor from the menu. However, in most cases I recommend the Export feature outlined above, as it is newer and has a few more options. The main advantage of Image Processor is that you can save to more than one derivative file format in one process, but for most typical situations this isn’t a significant advantage.

Exporting copies of photos from Bridge is covered in more detail in my “Adobe Bridge for Photographers” course, which of course is included in the GreyLearning Ultimate Bundle. You can find the individual course here:

https://www.greylearning.com/courses/adobe-bridge-for-photographers

You can also get the GreyLearning Ultimate Bundle with a discount included automatically by using this link to get started:

https://www.greylearning.com/bundles/greylearning-bundle?coupon=golive