Ask Tim Grey

Today’s Question: In your answer about dodging and burning in Lightroom Classic you mentioned the Density setting for the brush, which reminds me that I’ve never understood what the Flow setting does. Can you clarify the difference between these two controls?

Tim’s Quick Answer: The Flow and Density controls determine the overall opacity of your brush strokes and whether that opacity builds up with more painting or whether it is fixed at a specific value.

More Detail: The Density setting is understandably a little easier to understand compared to the Flow setting. Put simply, the Density control determines the opacity of the brush stroke you’re painting at any given time.

To provide an analogy, let’s assume we’re painting with black on a white canvas. If I paint with Density at 100 then I’m painting with pure black, totally covering up the white canvas. If I paint with Density at 0 then I’m not actually painting at all. Painting with Density settings in between will yield what amounts to a shade of gray, such as middle gray with a Density value of 50.

If the Flow is set to 100, then you will be consistently painting at a single Density value. For example, if you are painting with Density set to 50 and Flow set to 100, you’re painting with middle gray. Even if you overlap the same area multiple times with a single brush stroke, you’re always painting with middle gray in this example.

If you reduce the value for Flow, you can think of the virtual paint as flowing from the brush at a slower rate. I’ll over-simplify the math here to make the concept easier to understand. Let’s assume the Density is set to 100 and the Flow is set to 20. When you initially paint, you’ll be painting at an effective Density of 20, since that is the setting for Flow. When you paint over the same portion of the brush stroke a second time, the Density goes up to 40 for that area. As you continue passing over the same area while painting, evenaully it will get up to the full value for Density.

So, for example, you could set the Density to 50 and the Flow to 10, and it would take multiple passes over the same area before the Density reaches 50, but no matter how many times you keep painting over that same area again within a single brush stroke the resulting Density won’t go above 50.

In the context of masking, the shades of gray used above for illustrative purposes relate to the strength of the adjustment. So, you can use a lower setting for Density to have a reduced adjustment effect in specific areas of the image, and you can use a reduced value for Flow if you want to be able to build that adjustment up within a single brush stroke based on how many times you overlap the same area.

Personally, I find the behavior of a reduced Flow setting has a tendency to cause obvious patterns of variability, such as striations of uneven adjustment. I therefore prefer to leave the Flow setting at the maximum value of 100, and instead vary the Density setting as needed from one brush stroke to the next to achieve the desired result.

Today’s Question: Following up on your answer about dodging and burning in Photoshop, is there a technique that provides similar results you would recommend for those of us only using Lightroom Classic and not Photoshop?

Tim’s Quick Answer: You can apply dodging and burning adjustments in Lightroom Classic (or Camera Raw or Lightroom) using the Brush feature of the Masking adjustments, with separate masks for dodging and burning.

More Detail: Today’s question is a follow-up to my answer yesterday about my preferred technique for dodging and burning in Photoshop. You can perform much the same task in Lightroom Classic (or Camera Raw or Lightroom) by using individual masks for dodging and burning, in conjunction with the Brush feature.

To get started, add a new mask with the Brush option, and make sure the Feature setting is not at zero (you may even want it all the way at 100). You can also reduce the Density setting to about 20 if you want to be able to build up an effect with varying degrees of adjustment. Paint an initial area of the image you want to apply the adjustment to in order to create an actual mask. Then apply an adjustment, such as to increase the value for Exposure slightly, perhaps up to a value of 0.50 for a half-stop of brightening.

To avoid confusion, right-click on the mask you just created and choose Rename from the popup menu. In the Rename dialog enter a meaningful name for the mask, such as “Dodging (Brighten)”, since the Exposure value was increased for this mask.

Repeat the same steps above but with a negative value for the Exposure slider, renaming that mask to something like “Burning (Darken)”. You can then click on the applicable mask and paint in additional areas. The overall Exposure adjustment (and any other adjustments you want to apply to the applicable areas) will affect the image based on the mask, which means there can be a variable effect if you used a relatively low setting for Density and painted over some areas multiple times, or if you used a different Density setting for various brush strokes.

It can seem a little cumbersome to apply dodging and burning in this way using two masks, with one for lightening and one for darkening. However, with a little practice it can be a very effective technique for lightening and darkening specific areas of a photo to determine how much detail will be visible in different areas and how much overall contrast there will be.

Today’s Question: I’m getting back into using Photoshop more in addition to Lightroom Classic, in an effort to exercise more control over my photos. Can you remind me of the technique you recommend for dodging and burning in Photoshop?

Tim’s Quick Answer: I recommend dodging and burning on a separate image layer in Photoshop, using the Overlay blend mode in conjunction with painting with black or white at a reduced opacity to darken or lighten specific areas, respectively.

More Detail: I’m sure part of the reason I like to use a dodging and burning technique to selectively lighten and darken specific areas of a photo is that I enjoyed the process working in the wet darkroom for the first time during a black and white film photography class back in high school. I also appreciate the degree of control it enables you to exercise over how detail is presented in the image.

While there are various ways you can apply dodging and burning to an image in Photoshop, my preferred method involves a separate layer with specific settings, so you can paint to lighten and darken using the Brush tool.

To get started, select the top-most image layer on the Layers panel, which may mean simply selecting the Background image layer. Then hold the Alt key on Windows or the Option key on Macintosh while clicking the “Add New Layer” button (the plus within a square icon) at the bottom of the Layers panel.

In the New Layer dialog, enter a meaningful name in the Name field, such as “Dodge and Burn”. Set the Mode popup to Overlay (Soft Light can also be used for a more subtle effect), and turn on the “Fill with neutral color” checkbox. Click OK to create the new layer.

Next, select the Brush tool from the toolbox, and press the letter “D” on the keyboard to set the default colors to black and white. On the Options bar, make sure the Mode popup is set to Normal, as we want the Overlay blend mode set for the layer not for the brush. Then set the Opacity to a value of between 10% and 20%. Be sure you have selected a brush with a soft edge, generally with a Hardness setting of 0%.

You can then paint with black to darken and white to lighten. To switch between black and white as the color you’re painting with you can press the letter “X” on the keyboard to swap the foreground and background colors.

Since this technique involves adding a layer to the image, you’ll obviously want to make sure you preserve those layers for future editing as needed. That means you’ll need to save the image as a TIFF or PSD file with layers included.

Today’s Question: As a follow-up to your answer about nudging the rotation of an image to straighten a horizon, how do you deal with a situation where lines in a scene make it appear there is a crooked horizon even when the image is perfectly level? For example, the shoreline of the opposite side of a lake might appear to slope upward from left to right, even though the camera was completely level.

Tim’s Quick Answer: Ultimately, I recommend rotating so the image looks as correct and natural as possible, even if that means that a line that could be mistaken for a horizon is not perfectly horizontal.

More Detail: When it comes to rotating an image by an arbitrary number of degrees, to me the ultimate goal is for the image to look natural, or to not appear to the viewer to be crooked. This can sometimes be difficult to accomplish, such as when there are lines in the scene that trick the eye into seeming like a horizon that isn’t straight.

If there are elements within the scene that should be perfectly vertical, such as buildings or a flagpole, you can use those as a reference for rotation. If those elements are easy to see in the photo, it can be more important for them to be straight than for a “false horizon” to be made horizontal.

In some cases, you may find that leveling the image based on gravity (such as by using an in-camera leveling feature) results in an image that appears to have a crooked horizon. But then when you rotate the image so the fake horizon is perfectly horizontal, that looks wrong too. In this type of situation I’ll compromise, rotating somewhere in between, trying to strike a balance that looks best overall.

Ultimately what generally matters most is how the image is perceived, regardless of which lines may or may not appear perfectly horizontal or vertical. Therefore, I recommend evaluating the image based on what looks most natural, even if there are crooked lines. It can also be helpful to get input from other people, so you have more of a consensus about what looks best for a particular image.

Today’s Question: I back up to Carbonite and two external hard drives. What is the value of syncing in Lightroom Classic?

Tim’s Quick Answer: In my view the primary reason to synchronize photos to the cloud from Lightroom Classic is not to back them up but rather to enable you to access selected images from virtually anywhere on just about any device.

More Detail: While synchronizing photos to the cloud from Lightroom Classic does provide an offsite backup by virtue of having copies of those photos stored on remote servers, to me the real reason to synchronize is to enable a more flexible workflow where you can access your photos from just about anywhere.

Once you’ve enabled synchronization for one or more collections in Lightroom Classic, the photos in those collections will be available throughout the Lightroom ecosystem. That includes accessing the images from a smartphone or tablet using the Lightroom mobile app, from just about any internet-connected device using Lightroom in a web browser (https://lightroom.adobe.com), or from another computer using the Lightroom desktop application.

For example, you might synchronize photos from Lightroom Classic to the cloud so you can review those images on your mobile device while traveling. You could also use a synchronized collection to share photos with a client on a tablet or smartphone.

With this workflow, you can choose specific photos you want to synchronize to the cloud, whether for reviewing and updating, sharing with others, providing a backup of selected images, or any other reason you may find it helpful to be able to access photos from virtually anywhere.

Today’s Question: You mentioned that it is only possible to have a single catalog synchronized to the cloud in Lightroom Classic. But if I signed up for a second Creative Cloud subscription, wouldn’t that enable me to synchronize an additional catalog.

Tim’s Quick Answer: Yes, if you add a second Adobe Creative Cloud subscription you would be able to synchronize one Lightroom Classic catalog for each of your two subscriptions. You would also need to sign out of one account and into the other to change which images you were viewing and updating via synchronization.

More Detail: You can only enable synchronization for a single Lightroom Classic catalog, because that synchronization is associated with your Adobe Creative Cloud. When you enable synchronization for collections in Lightroom Classic, the images in those collections are available from virtually anywhere using the Lightroom mobile app, Lightroom website, or Lightroom desktop application.

If you wanted to enable synchronization for more than one Lightroom Classic catalog, you would need to sign up for an additional paid Creative Cloud account. You could then synchronize one catalog for each of your accounts.

However, the actual workflow involved with this approach would not exactly be streamlined. In order to switch between the catalogs for each account, you would need to sign out of one Creative Cloud account and into another account.

If you were using Lightroom Classic with two different Creative Cloud accounts on two different computers, working with Lightroom Classic would not be too complicated. However, if you were accessing the synchronized images via Lightroom mobile or Lightroom web, you would need to sign out of one account and into the other to change which collections from which catalog you were currently browsing.

In my view, the simpler approach would be to use a single catalog in Lightroom Classic rather than two catalogs, and then to use some method of identifying collections in a way that would identify which catalog they would have been in had you been using two catalogs. In my view this would be less cumbersome than trying to manage two different Creative Cloud accounts.

Today’s Question: If you add color labels in Lightroom, will they show up in MacOS Finder? And vice versa?

Tim’s Quick Answer: No. The color labels available on MacOS are specific to the operating system, and MacOS doesn’t display the contents of the Label field in metadata where the color label is stored by Lightroom and other applications.

More Detail: While the concept of assigning color labels to files in MacOS is similar to the ability to assign color labels in other software such as Lightroom Classic, Adobe Bridge, and other applications, the two features are not related to each other.

The color labels you can assign in MacOS are an operating system feature, and the information is not stored directly in the files themselves. This is why, for example, if you synchronize files to the cloud that have MacOS color labels, those color labels won’t appear when the files are accessed from a different computer.

The color labels assigned by Lightroom Classic, Bridge, and other applications, use the Label field that is part of the XMP metadata standard. The implementation involves simply adding a word to the Label field, which some software applications will then translate to the display of a specific color for an image. Note, for example, that by default Lightroom Classic uses the word “Red” for a red color label, while Adobe Bridge uses the word “Select” for a red color label.

So, the MacOS color labels and XMP metadata labels are completely different metadata values implemented in completely different ways. Software such as Lightroom Classic does not support the MacOS color labels, and when you display metadata for images using MacOS the Label field (and therefore the color label value) is not displayed.

Assuming you are saving metadata to files for your images in Lightroom Classic, you could browse your color labels in Adobe Bridge or another application that supports that metadata. Just be sure not to make any changes to that metadata outside of Lightroom Classic, because doing so will cause a metadata mismatch.

Today’s Question: I have some images of a seascape, and my horizon always looks off. It’s almost like I can’t “snap” it into place. Even the Auto or Level doesn’t get it quite right. I’m wondering if there was a keyboard shortcut to rotate just a smidge, or a pixel?

Tim’s Quick Answer: Yes, you can nudge the rotation when cropping by clicking the mouse in the Angle field and pressing the up or down arrow keys to rotate one-tenth of a degree at a time.

More Detail: When cropping in Lightroom Classic or Camera Raw you have several options for adjusting the rotation of the image, such as to straighten a crooked horizon. Those include dragging your mouse just outside the crop box, clicking the Auto button in Lightroom Classic, using the Straighten tool (the bubble level icon), or entering a manual value in the Angle field.

One of the great tricks for fine-tuning almost any adjustment in Lightroom Classic or Camera Raw is to use the arrow keys to increase or decrease the numeric value associated with the adjustment, which includes the Angle field for rotating while cropping.

You can click the mouse on the textbox to activate the field, and then use the up and down arrow keys on the keyboard to increase or decrease the value, respectively. In the case of the Angle field the up arrow will rotate clockwise by one-tenth of a degree, and the down arrow will rotate counter-clockwise by one-tenth of a degree.

If you initially need a stronger adjustment, you can hold the Shift key while pressing the up or down arrow keys, which will rotate by one-half a degree for each press of the key.

Note that this same behavior is available for the other textboxes associated with adjustments, such as for the many adjustment sliders. In most cases the up and down arrow keys will adjust the value by one, and holding the Shift key will cause the up and down arrow keys to adjust the value by ten. However, the actual result will vary among some of the adjustments.

Today’s Question: You’ve mentioned that you recommend getting a high-resolution 4K display, but that you don’t set the display to maximum resolution. Why buy a high-resolution display if you’re not going to use that high resolution?

Tim’s Quick Answer: I recommend opting for a display with a high resolution (such as 4K or 5K) to provide excellent display quality, but prefer to set the display at a lower resolution so that interface elements are larger and text is more legible.

More Detail: It might seem odd to purchase a high-resolution display and then not take advantage of that high resolution. However, in my view setting a high-resolution display to a resolution less than the maximum it supports provides what I consider to be the best balance.

High-resolution displays have more pixels, which translates to smaller pixels compared to a display of the same size but lower resolution. Those small pixels enable the display to present finer resolution, which translates to improved image quality.

The downside of a high-resolution display is that when used at the maximum resolution setting software interface elements can be very small, which can be problematic. This can also lead to a situation where text is too small to be able to read if the software in question doesn’t provide good scaling options.

By choosing a display that has a high resolution such as 4K (approximately 4,000 pixels across) or 5K (about 5,000 pixels across), you’ll get the advantage of finer detail and higher image quality. By setting that display to a lower resolution setting, you’ll get the benefit of interface elements and text that are at a better size.

The key benefit of this approach can best be seen by comparing two displays next to each other. For example, if one display features 1920×1080 resolution, and the other supports 4K (typically around 3840×2160 pixels), when both are set to 1920×1080 resolution the 4K display will look sharper with better image quality.

If you’re comfortable with the display size when set to the full resolution your display is capable of, that’s perfectly fine. But if like me you prefer to set the display to a lower resolution, there is still an advantage to choosing a display with a higher resolution than you’ll be setting that display to.

Today’s Question: I have two Lightroom Classic catalogs (I know you don’t recommend this, but it suits my needs). I have synchronization enabled for my primary catalog, but every time I open the second catalog, I’m prompted to synchronize that catalog. I only want to have synchronization enabled for the primary catalog. Is there a way to get Lightroom Classic to stop asking me to synchronize the second catalog?

Tim’s Quick Answer: Yes, you can disable this message by deleting the catalog helper file that contains the sync data for the catalog you don’t want to enable synchronization for.

More Detail: Lightroom Classic only allows you to enable synchronization to the cloud for a single catalog. If you open a catalog and get a message asking if you want to enable synchronization for that catalog, this is an indication that synchronization had been enabled at one time for this catalog, but that you then switched to synchronizing a different catalog.

To disable this message, you can delete the sync data file associated with the catalog. First, open the catalog that you don’t want to enable synchronization for and open the Catalog Settings dialog (found on the Edit menu on Windows or the Lightroom Classic menu on Macintosh). Go to the General tab and click the Show button in the Information section. This will open a window in your operating system with the folder containing your catalog files selected.

Open the selected folder to view the catalog files. Locate the file that has the same name as the primary catalog file (the file with the .lrcat filename extension) that also includes “Sync” as part of the filename. For example, if the primary catalog file is called “Lightroom Classic Catalog.lrcat”, the sync file would be called “Lightroom Classic Catalog Sync.lrdata”.

Once the sync data file is removed, when you launch Lightroom Classic you’ll no longer be prompted to enable synchronization for this catalog.