Category: Ask Tim Grey

Today’s Question: Would you please describe the difference between a background layer and normal layer [in Adobe Photoshop] and when it is advantageous to use one over the other?

Tim’s Quick Answer: The “Background” image layer in Photoshop is simply a “normal” image layer is set to “Background” status. What that primarily translates to is that the Background image layer is locked so that certain changes can’t be applied to the Background layer. This is aimed at preserving (to some extent) the contents of the Background image layer.

More Detail: In Photoshop it is possible to have multiple image layers in a single document. That might represent a composite panorama, for example, where the multiple layers represent the several frames that have been assembled into the panoramic image. Those layers could also represent a composite image, such as when an object is added to an underlying photo, or you might use a separate image layer for image cleanup work, painting pixels to cover up blemishes in the image below.

The “Background” image layer in Photoshop generally represents the original image before adjustments have been applied. But in reality, “Background” is simply a status for an image layer in Photoshop. One of the key attributes of a Background image layer is that it can’t be transformed or moved, unless you first convert the Background layer to a normal layer. This helps protect the “original” version of the image, since you can perform your work on separate image or adjustment layers without altering the Background layer.

You can convert a Background image layer to a normal (non-locked) layer by choosing Layer > New > Layer from Background on the menu. You can also convert a normal image layer to a Background image layer by selecting the layer on the layers panel and choosing Layer > New > Background from Layer on the menu.

In general, I recommend simply leaving the Background image layer alone. That way you can preserve the “original” appearance of the image. Adjustments and other effects can then be applied by adding adjustment layers or other image layers as needed to achieve the desired result.

In other words, if you need to use a layer for a task in Photoshop, it will be a normal layer rather than a Background image layer. If you need to perform a task that requires you to work directly on pixels (such as with many filters) you may need to create a copy of the Background layer for this purpose. For many other tasks (such as most image cleanup work) you can simply use a new empty image layer for that work.

Today’s Question: I always use the same card in my camera (not a choice, just lazy). Should it be rotated with other cards for longer life and less chance of failure, or does it matter?

Tim’s Quick Answer: I wouldn’t worry about rotating among several cards, as long as you replace your cards periodically and don’t ignore any signs of possible corruption.

More Detail: Media card are generally very dependable. If they are going to fail, they will most likely either fail very early on due to a manufacturing defect, or fail when they reach the end of their useful life. Rotating among cards won’t provide much benefit, other than the fact that it means it will take longer to get to the end of the useful life for a given card.

When I refer to the end of a cards useful life, that generally means reaching the maximum number of write operations for the memory of the card. That generally translates into 100,000 write cycles or more. However, that doesn’t quite convey how long it would take (on average) for a card to fail. That is because media cards use strategies such as wear leveling to help balance out the use of the memory blocks on the card and help extend the overall life of the card.

In other words, as long as you don’t happen to get a card that fails early, odds are you’ll replace a card long before it would otherwise fail. That might be because you want more capacity, you need a different card type for a new camera, you lost a card, or any other reason. The point is, in general media cards will last a long time, and switching between various cards won’t provide any significant benefit in terms of the potential of a given card to fail early.

Today’s Question: Suppose I photograph a painting with the intent of making a print of it that is as faithful as possible to the original. Assuming I have a good, calibrated monitor and good printer with a good profile for the paper I use, can I get a good result if I simply place an 18% gray card in the camera view and use Photoshop to make it look like the original card?

Tim’s Quick Answer: This is actually a good example of a scenario where using a product such as the ColorChecker Passport (https://timgrey.me/colorchecker) from X-Rite to create a custom profile for your camera based on the conditions under which you are photographing the painting.

More Detail: While photographers generally want the colors in their photos to be “accurate”, we also want to exercise a bit of creative interpretation. So we might warm up an image more than the scene really appeared, or boost the saturation a little bit.

In some cases though, such as with product photography or when reproducing a painting or other artwork, you often want the colors in the final photo to be as close to a perfect reflection of the original as possible. In other words, you want to have a photo with accurate colors that appears as though the scene had been illuminated by perfectly white light (with no color cast).

In this type of situation there are a variety of approaches you could take to help ensure more accurate colors. As noted in the question, you could include a gray card in the frame and then adjust the colors so that gray card appears perfectly neutral gray.

You could also use a custom white balance setting in the camera, which is a somewhat automated approach to the use of a gray card for a post-processing adjustment. In effect, the gray card is neutralized in the camera rather than after the capture.

An even better option in terms of color accuracy is to use a product such as the ColorChecker Passport from X-Rite Photo (https://timgrey.me/colorchecker). The ColorChecker Passport includes a variety of color swatches (including gray) that you can photograph under the same lighting conditions as the subject you’ll photograph. You can then photograph the subject with the same camera settings.

After the photo shoot, you can use the photo of the ColorChecker Passport to build a custom profile for that specific photo shoot. The profile can then be applied to the photos, to help ensure the most accurate colors possible.

You can get more details about the ColorChecker Passport here:

https://timgrey.me/colorchecker

Today’s Question: I am working in Lightroom Classic. Sometimes my Lightroom screen will–all of a sudden and randomly–only show my pictures. My panels and filmstrip are gone (black area). What am I hitting and what do I need to do to get them back? Currently I quit and reopen to get them back.

Tim’s Quick Answer: It sounds like you are inadvertently entering “Lights Out” view in Lightroom Classic. You can toggle between the dimmed mode, full Lights Out mode, and normal mode, by pressing the letter “L” on the keyboard.

More Detail: The “Lights Out” view in Lightroom Classic can certainly be helpful in terms of enabling you to focus exclusively on an image (or multiple images) without the distraction of the overall Lightroom Classic interface. Of course, if you’re accidentally entering Lights Out view it can be a bit disconcerting.

You can access the Lights Out view options on the Window menu on the menu bar in Lightroom Classic. Simply choose Window > Lights Out, and then select either Lights Off (for a black interface so you only see your photos), Lights Dim (so the interface is dimmed so it is not very visible, but the photos appear normally), or Lights On (so you see the full normal interface along with your photos).

You can also press the letter “L” on the keyboard to cycle through these three Lights Out views. The first time you press “L” the interface will be dimmed, with the photos appearing normally. The second time you press “L” the interface will be blacked out, and the third time you press “L” you’ll return to the normal view mode.

The Lights Out view is especially helpful when you are in the Loupe view, so you can focus more attention on the single image you’re browsing. But of course, you may also find this view option helpful even in the grid view display, so you can review a set of thumbnails without distraction.

Most importantly, of course, is to understand that this view option exists, so that if you accidentally press the “L” key on the keyboard, you’ll know why the Lightroom Classic interface got dimmed or hidden.

Today’s Question: When I resize an image in Photoshop, the math doesn’t seem to add up. For example, with pixel dimensions of 5472×3648 in the Image Size dialog Photoshop shows “114.2M”, which I assume refers to megapixels. But the actual number of megapixels is about 20. What is the 114 number based on?

Tim’s Quick Answer: The “114.2M” value in this example refers to the estimated file size in megabytes for the image, not megapixels. In addition, the estimated file size will often not be accurate, depending on how you save the image.

More Detail: The Image Size command in Photoshop enables you to change the actual pixel dimensions of an image, so that you can resize an image for specific output. This is helpful, for example, when you want to print an image at a specific size.

The “M” value shown at the top-center of the Image Size dialog stands for “megabytes”, and represents the estimated file size for the image when you save it at the current size. However, there are a variety of factors that affect the file size, which can cause the number shown in the Image Size dialog to be quite inaccurate.

Think of the file size estimate in the Image Size dialog to be based on saving the current image as a TIFF file with no layers, and with no compression applied. If you save an image in this way, the file size shown in the Image Size dialog will be quite accurate.

If you save the image as a JPEG, the file size will be considerably smaller because of the lossy compression applied, with the actual file size depending on the pixel dimensions, the image quality setting used for the JPEG compression, and the complexity of the image itself.

If you save the file as a TIFF with a significant number of layers (especially image layers) and without any compression applied, the file size may be significantly larger than the estimate in the Image Size dialog.

Therefore, in many cases the file size estimate shown in the Image Size dialog is not especially useful. If you are familiar with file size as it relates to the potential output size in the context of a flattened TIFF image with no compression applied, the value may be somewhat useful. But in general I recommend ignoring the value shown, other than as a very rough guide to how much space the file might require when saved to your hard drive.

Today’s Question: Every time I open Photoshop, I immediately have to wade through several “ads” telling me how I can adjust my photos. Is there a way to skip that so I can get to what I want to do?

Tim’s Quick Answer: The screen you’re referring to is the “Home” screen, which you can disable by turning off the “Auto show the Home Screen” checkbox on the General tab in Preferences.

More Detail: A while back Adobe added a “home” screen in Photoshop, which by default is displayed when you initially launch Photoshop or anytime you close all images that had been open. The home screen shows links to lessons related to Photoshop, along with a list of recently opened images. Along the left side of the home page there are also buttons for creating a new document or opening a file, along with links to cloud-based storage and a handful of other options.

If you prefer not to see the home screen you can turn it off in Preferences. Start by selecting Photoshop > Preferences > General from the menu on Macintosh or Edit > Preferences > Genera on Windows. On the General page of the Preferences dialog you can then turn off the “Auto show the Home Screen” checkbox, found in the Options section. Next time you launch Photoshop (or close all documents) you will no longer see the home screen.

Note that you can bring up the home screen at any time if you’d like by choosing Help > Home from the menu, in case you do want to take a look at the home screen at any time even if it is disabled in Preferences.

Today’s Question: I went to use the Library Filter to locate photos by date. In the Date column every single date was listed individually, which is different from what is shown in one of your videos on the subject, where you were able to select by year or month. How can I get the years and months back on the list?

Tim’s Quick Answer: You can return to the option to select (and expand or collapse) based on months and years with the Library Filter by setting the Date column to the Hierarchical rather than Flat setting.

More Detail: The Library Filter in Lightroom Classic (View > Show Filter Bar) can be tremendously helpful in locating particular photos, especially when you want to be able to search across a large group of photos. You can even search among all images in your Lightroom Classic catalog using the Library Filter.

Among the various options found on the Metadata tab of the Library Filter bar is a Date option, which of course enables you to search for images based on the date of capture. Needless to say, if the list of dates in the Date column includes every single date for which at least one photo was captured, that list will be long and daunting.

Fortunately, it is easy to return to the hierarchical option, which enables you to collapse or expand (and filter) based on years, months, and days. In other words, you can see only years on the list, or expand some (or all) years to see the months, and then also expand the months to reveal days.

You can switch between the Hierarchical and Flat options on a popup menu found by clicking the small popup icon at the far right of the Date heading on the Metadata tab of the Library Filter bar. The button shows a set of uneven horizontal lines, and may not appear unless you hover your mouse over the Date column, depending on where that column is positioned.

When you click the popup button, you’ll see options for “Hierarchical” and “Flat”. In general I recommend selecting Hierarchical, since this provides a much more manageable list of dates to choose from when you are filtering your images to locate a particular photo.

Today’s Question: Why would a mirrorless camera have an option to use a mechanical shutter that reduces the frame rate?

Tim’s Quick Answer: A mechanical shutter ensures you will not end up with visual artifacts in photos that include movement in the scene, which can result from a completely digital shutter with the image sensors in most digital cameras.

More Detail: The image sensors in most digital cameras use what is often referred to as a “rolling shutter”. Rather than the entire image sensor being recorded at one time, the sensor values are read row by row. With very fast-moving subjects in a scene you are photographing, this can lead to visible artifacts or aberrations in the image.

For example, if you capture a photo of the spinning propeller of an airplane using an electronic shutter, you will often see that the propeller appears to have several pieces that are floating, not appearing connected to the actual propeller blades.

There are, of course, some advantages to an electronic shutter. You can generally achieve a much faster shutter speed with an electronic shutter compared to a mechanical shutter. You can also (as noted in today’s question) achieve a faster frame rate with an electronic shutter compared to a mechanical shutter. An electronic shutter can also be completely silent, which is not possible for a mechanical shutter.

In other words, there are benefits to both types of shutters, depending on the situation. This is the reason some cameras that feature an electronic shutter will also include a mechanical shutter. This enables you to switch between the two options depending on the specific needs for the scene or subject you are photographing.

Today’s Question: What is the best way to move files that are located in Lightroom [Classic]? Copy and paste the files outside of Lightroom and then reconnect, or move the files within Lightroom? I have about 30,000 images that need to be moved. I want to be careful, but also this could be very time consuming moving the files one at a time and then reconnecting them.

Tim’s Quick Answer: You should absolutely move the photos (and folders if applicable) within Lightroom Classic, not through your operating system. This is actually one of the most important “rules” to make sure you don’t create a mess within your Lightroom Classic catalog.

More Detail: It is critically important that once you start using Lightroom Classic to manage your photos, all tasks related to the photos you have imported into your catalog be performed within Lightroom Classic. Performing work with your images outside of Lightroom Classic is perhaps the fastest way to create a mess in Lightroom Classic.

If you want to move a photo within Lightroom Classic, you can simply drag-and-drop that photo to the desired destination folder. By default you will see a dialog asking for confirmation that you want to move the file on your hard drive, which is in large part serving as a reminder that when you move a photo within Lightroom Classic, it is actually being moved on your hard drive as well.

Similarly, you can drag-and-drop entire folders to move the folder and its contents from one storage location to another. Taking that a step further, you can also create new folders, even on a hard drive you aren’t yet using to store photos that are managed by Lightroom Classic. The option to create a new folder is on the popup menu associated with the plus symbol (+) to the right of the Folders heading on the left panel in the Library module.

While it is certainly possible to move photos using your operating system and then reconnect the photos (and folders) that appear missing as a result in Lightroom Classic, in my mind that approach is a recipe for disaster in your Lightroom catalog. Fortunately, you can easily perform that work within Lightroom Classic and avoid creating a mess in your catalog.

If you already have a bit of a mess in your Lightroom Classic catalog, note that I’ll be presenting a live online workshop during the month of August focused on “Cleaning Up Your Mess in Lightroom Classic”. You can learn more about this learning opportunity on the GreyLearning website here:

https://www.greylearning.com/courses/online-workshop-mess/

Today’s Question: I need to find an app that will show me where shadows will be at any given time. A friend suggested Sun Locator, but it’s apparently not available on iPhone. It had a visual that showed the thrown shadow that moved as you moved the time. Is there one that you use?

Tim’s Quick Answer: One of the top apps that enables you to plan for shadows is The Photographer’s Ephemeris (https://timgrey.me/tpeios). On the map you can see an indication of the direction and relative size of shadows, as you pan through the timeline.

More Detail: I use The Photographer’s Ephemeris (TPE) as a tool for planning to make use of the sun (or sunlight) and moon in my photography. Among the various features in TPE is an indicator of the direction and relative size of shadows.

You start by setting the position from which you intend to photograph, or for the subject you’ll be photographing. You can then set the date based on when you’ll be photographing, and pan through the timeline. As you pan from sunrise toward sunset, for example, you’ll see the indicator for shadows start to shrink as you move away from sunrise, and then grow again as you get closer to sunset.

The direction of the gray shadow lines indicates the direction the shadows will be cast, which obviously depends upon the relative direction to the sun as it arcs across the sky. The size of the lines gives you a sense of the relative size of the shadows you can expect.

Another tool I use (and for which I am currently producing a video training course) is PhotoPills, which includes a calculator you can use to determine the actual length of shadows based on the height of an object and of course the relative position of the sun.