Ask Tim Grey

Today’s Question: I am desperate. I lost my screen mode in Photoshop. When I launch Photoshop I get the tools and the menu bar and the panels, but with the operating system in the background. How can I get the background back?

Tim’s Quick Answer: The “background” you’re referring to is the Application Frame. You can bring back this interface option by choosing Window > Application Frame from the menu.

More Detail: The Application Frame setting is only an option for Macintosh users. Windows users always have a background in Photoshop. Macintosh applications (including the Macintosh version of Photoshop) are able to have a minimal interface where you only see open documents and interface elements such as toolbars.

In other words, Macintosh users have the option of an interface that appears somewhat “see through”, which can be a little distracting depending on what’s going on behind Photoshop. As a result, I prefer having the Application Frame turned on, and recommend that all photographer’s do the same.

As noted above, you can choose Window > Application Frame to turn this background on or off.

Today’s Question: I went to a folder from a trip of several years ago, looking for some videos I captured during that trip. I know these videos work fine, as I can access them from my operating system. But Lightroom shows a black exclamation point icon at the top right of each thumbnail, and when I put my mouse over that exclamation point it shows a message that says “Lightroom has encountered problems reading this video”. Is there anything I can do to get my videos back in Lightroom?

Tim’s Quick Answer: This scenario most likely indicates the cache for video files has become corrupted. To purge the cache so it can be rebuilt, click the “Purge Cache” button in the Video Cache Settings of the Performance tab in the Preferences dialog in Lightroom. When you restart Lightroom the videos should perform normally again.

More Detail: Lightroom uses a cache to help improve performance for playing videos within Lightroom. If that cache becomes corrupted for any reason, you may not be able to play some (or all) videos within your Lightroom catalog. The fact that these videos can be played normally outside of Lightroom further confirms that the issue is with Lightroom’s video cache.

Fortunately, it is very easy to purge the video cache, which will not cause any important data to be lost. When you then re-launch Lightroom you should be able to view all videos normally again, with the video cache being regenerated automatically.

As noted above, purging the cache for videos in Lightroom is very simple. First, bring up the Preferences dialog by going to the menu and choosing Edit > Preferences on Windows or Lightroom > Preferences on Macintosh.

Navigate to the Performance tab using the row of buttons across the top of the Preferences dialog, and look for the “Video Cache Settings” about midway down the dialog. At the far right of this dialog you can click the “Purge Cache” button to clear the video cache.

If you work with video on a regular basis in Lightroom, you can improve performance for video playback by increasing the cache size, provided you have adequate hard drive space available. The default value for Maximum Size for the cache is 3 GB, but you can increase the value. You can also turn off the “Limit video cache size” checkbox if you want to allow Lightroom to make use of as much free hard drive space as is available.

When you have adjusted the settings in the Preferences dialog, including purging the video cache, you can restart Lightroom to return to normal use of your videos.

Today’s Question: I am encountering this error message when exporting a catalogue: “Lightroom encountered an error when reading from its preview cache and needs to quit.” Any advice as to why and what the remedy is.

Tim’s Quick Answer: This error message indicates that the previews file has become corrupted. You will need to delete the previews and have Lightroom rebuild them.

More Detail: In the folder where your Lightroom catalog is stored, there is also a “Previews” file. Only the Previews file should be deleted, leaving all other files where they are. In particular, you need to be careful not to delete the “lrcat” file, which is your actual Lightroom catalog.

To locate the folder containing your catalog, you can choose Catalog Settings from the menu. This is found on the Edit menu on Windows and on the Lightroom menu on Macintosh. On the General tab in the Catalog Settings dialog you can click the Show button to open a window in your operating system showing you the folder that contains your catalog. Close Lightroom before deleting the Previews file.

Then open the folder that contains the Lightroom catalog. You will see a file that has the same base filename as your catalog, followed by “Previews.lrdata”. That file with the “Previews.lrdata” ending is the only file you need to delete. You can also move it to a different location if you want to be extra cautious.

After deleting (or moving) the Previews file, re-launch Lightroom. Initially there won’t be previews for any of your images, but Lightroom will generate them again as you browse the photos. You can also generate them all in one process, though it will require considerable time depending on how many images are in your catalog.

To build previews for all photos in your catalog, first make sure all hard drives used to store photos for your Lightroom catalog are connected. Then select the All Photographs collection in the Catalog section of the left panel in the Library module, and make sure there aren’t any filters applied that would cause you to only see a portion of your photos. Then choose Edit > Select All from the menu to select all photos. Finally, choose Library > Previews > Build Standard-Sized Previews from the menu. Lightroom will then generate previews for all photos, with the progress shown on the identity plate at the far left side of the top panel.

Today’s Question: Your answer about long exposures a few days ago mentioned that with a very long exposure moving subjects in a scene might disappear altogether. Could this be a way to have people in a scene not appear in a photo?

Tim’s Quick Answer: Yes, indeed! Provided there is enough movement of the people during an extended exposure, a long exposure can provide a method for having the people disappear from a scene in your photograph.

More Detail: When you capture a photo of a scene that includes some degree of motion with a moderately long exposure, the areas of movement will be blurred. An example would be a waterfall photographed at a relatively slow shutter speed. With a fast shutter speed you can see considerable texture and detail in the water, while with a slow shutter speed the water will take on a smooth and silky appearance.

With a scene such as a waterfall, the degree of detail will gradually diminish as the exposure gets longer. In some cases, however, a particularly long exposure can cause moving subjects to simply disappear altogether from the frame.

For example, let’s assume you are capturing a 30-second exposure, and that during the exposure a bird flies through the frame. If the bird takes one second to fly across the full frame, it would only appear within the frame for 1/30th of a second. Furthermore, the bird would only appear in a specific portion of the image for a tiny fraction of a second. That simply wouldn’t be long enough to register as visible pixels in the final image.

This same concept can be used to capture a scene containing people so that all of the people disappear. The challenge is to make sure the exposure is long enough (and the movement of the people great enough) that the final photo won’t contain any people at all. If the scenario involves a single person walking briskly through your scene during the exposure, a 30-second exposure would almost always be adequate to ensure the person doesn’t appear in the photo at all. In other cases you might need a significantly longer exposure to accomplish this.

But as long as the exposure is long enough and the movement is fast enough, a long exposure can indeed cause all people to disappear from a photo of a scene.

Today’s Question: I just purchased and downloaded Aurora HDR 2019. My question is how can I get a photo from Lightroom to Aurora to edit the photo and bring it back to Lightroom?

Tim’s Quick Answer: To use Aurora HDR 2019 (https://timgrey.me/aurora2019) from Lightroom, it first needs to be installed as a plug-in. Next, select the captures you want to merge into an HDR image. Then go to the menu and navigate to File > Edit With Preset, where you can select “Open Source Files” from the submenu under the “Aurora HDR 2019” heading.

More Detail: Once you’ve installed Aurora HDR 2019, you’ll want to install the software as a plug-in for the host application(s) you want to use with Aurora HDR. To do so, first launch Aurora HDR, making sure you have quit the applications you want to use as a host for Aurora HDR.

On the Windows version of Aurora HDR you can then choose File > Install Plugins from the menu. On the Macintosh version choose Aurora HDR 2019 from the menu bar, followed by Install Plugins.

In the dialog that appears, you will find Install buttons for the applications that can serve as a host for Aurora HDR 2019. These include installation options for Photoshop, Lightroom, and Photoshop Elements. Click the Install button for each of the host applications you want to install Aurora HDR as a plug-in for.

Once Aurora HDR 2019 is installed as a plug-in for your preferred host applications, you can send images to Aurora HDR from those applications.

The process of sending original captures from Lightroom to a plug-in that creates an HDR image is different from the “normal” workflow for sending a photo to a more typical plug-in. Instead of using the Photo > Edit In menu, you will use the “Export With Preset” command. So, select the images you want to assemble into an HDR image, and then choose File > Export with Preset > Open Source Files. Note that the “Open Source Files” command will appear under a heading that says “Aurora HDR 2019” on the menu.

The selected images will then be sent to Aurora HDR 2019, where you can process them into a finished HDR image. When the process is complete, the resulting image will appear alongside the source photos within your Lightroom catalog.

If you’re interested in learning more about Aurora HDR 2019 (and getting a free trial to test the software out), you can do so by following this link:

https://timgrey.me/aurora2019

Today’s Question: I just installed all of the updates to my Adobe Creative Cloud applications, including Lightroom and Photoshop. I see the new features in Lightroom, but Photoshop doesn’t reflect any of the features for the new update. But the Creative Cloud applications shows that I’ve updated. Why can’t I get the new features if I’ve updated Photoshop?!

Tim’s Quick Answer: The latest (October 2018) release of Photoshop is actually a major update to a “2019” edition, replacing the 2018 edition. However, it is installed as a separate application, so you’ll need to be sure to launch the 2019 version to see the new features.

More Detail: Photographers who subscribe to the Adobe Creative Cloud Photography Plan (https://timgrey.me/photoplan) have gotten used to getting somewhat frequent updates to the various applications in the Creative Cloud. Generally, those updates are literally just an update to the existing application installed on your computer. In some cases, however, a completely new installation is created when you “update” an application.

Such is the case with the latest update to Photoshop, which is the “Adobe Photoshop CC 2019” version. Because this is a major update to Photoshop, it is installed as a separate version alongside the 2018 version.

This approach provides you with the opportunity to revert to the older version should there be any problems with the new update. However, this can obviously lead to some confusion if you are using a shortcut to the 2018 version when you think you’re launching the latest update.

To get to the new version, you can click the “Open” button to the right of Photoshop on the Apps tab of the Creative Cloud application. You can also go to the Applications (Macintosh) or Program Files (Windows) folder to launch the new version.

Once you’re happy working with the new 2019 version of Photoshop, you will want to update any shortcuts you use to access Photoshop (such as on the dock or Start menu), and uninstall the 2018 version so you’ll always be sure you’re only running the latest version of Photoshop.

Note that Adobe will most likely release a variety of updates to the 2019 version of Photoshop, which won’t require updating your application shortcuts until another “major” release (presumably for 2020) is available.

Today’s Question: For a few years now I’ve kept separate video and photo catalogs. However, I’ve discovered I like having the stills and videos in the same location. Is there any downside, besides storage space, to merging the two catalogs, keeping both stills and videos in the same catalog?

Tim’s Quick Answer: From my perspective it is generally advantageous to have all of your captures, whether still or video, managed in a single Lightroom catalog. To me the only other consideration would be whether certain captures don’t belong in Lightroom at all. But if you want to manage captures with Lightroom, my feeling is that all of those captures should be in a single Lightroom catalog.

More Detail: With very few exceptions, I recommend having all of your photo (and video) captures managed within a single Lightroom catalog. Put simply, if you want to manage any photos or videos in Lightroom, you should employ a single catalog for that purpose.

There are situations where you might not want to manage some captures within your Lightroom catalog. For example, the videos I capture for the express purpose of creating video training content for GreyLearning (https://www.greylearning.com) really don’t provide any advantage by being in my Lightroom catalog. I don’t need to manage those captures in the same way I need to manage my “normal” photos and videos.

As a result, for videos that are only intended to be produced into GreyLearning content, I will manage the content outside of my Lightroom catalog. But for any captures that I want to manage within Lightroom, I want to have in a single catalog.

By having all captures in a single catalog (rather than multiple catalogs) you can more easily locate specific content. You can always filter by media type (still versus video for example) or other criteria. But you don’t need to figure out which catalog to open in order to find specific captures.

For a typical photographer, in my mind there aren’t any reasons to employ more than one catalog. With very early versions of Lightroom it was problematic to manage a large number of captures in a single catalog. That is no longer the case, and performance is virtually identical with one large catalog versus multiple smaller catalogs. Furthermore, to me the advantages of using a single catalog far outweigh any potential disadvantages.

Today’s Question: Your answer about mirrorless versus SLR cameras made sense. But you didn’t indicate what you would choose if you were buying a new camera today. Do you might sharing where you stand on this decision?

Tim’s Quick Answer: I expect that my next camera will very likely be a mirrorless model. This expectation is based primarily on two considerations. First, I believe mirrorless cameras represent the future of photography. Second, for my specific photographic (and video) needs, mirrorless cameras offer some compelling advantages.

More Detail: One of the ways I often talk about mirrorless cameras is in the context of an imaginary world where mirrorless cameras already exist, but digital SLR cameras do not. In this context, where all cameras are mirrorless, my question is why you would suggest a mirror ought to be added to a mirrorless camera.

One of the key features of a mirrorless cameras is the absence of an optical viewfinder. To preview the photo you’re capturing, you either use a “live view” display on the camera’s LCD, or you make use of an electronic (rather than optical) viewfinder.

In the early days of mirrorless cameras, an electronic viewfinder represented a compromise. The resolution and quality of those electronic viewfinders didn’t provide anywhere near the quality of view you could achieve with an optical viewfinder, which in the context of an SLR camera provides you with an actual view through the lens at the scene you are photographing.

Many of today’s electronic viewfinders provide excellent resolution and image quality, while also providing a better preview of what your actual photo will look like compared to a simple view through an optical viewfinder.

In addition, the absence of a mirror mechanism provides a variety of other benefits, such as improvements to autofocus and previewing while capturing not only still photos but also video captures. The benefits related to video are of particular interest to me, since I capture a tremendous amount of video for the courses I produce for the GreyLearning library (https://www.greylearning.com).

So, if I were planning to buy a camera today, on balance I expect I would opt for a mirrorless camera. I do believe my next camera will be a mirrorless camera, and I’ll most certainly provide an update as soon as I make a decision about my future path related to photo gear.

Today’s Question: I’m constantly hearing about the advantages of mirrorless cameras compared to digital SLRs. But do those advantages still apply when the mirrorless camera is full-frame? Isn’t it then just as big and heavy as an SLR?

Tim’s Quick Answer: There is no question that mirrorless cameras provide some advantages (along with some potential disadvantages) compared to single lens reflex (SLR) cameras. In most cases, however, the size and weight benefits don’t relate so much to SLR versus mirrorless, as they do to the size of the image sensor used in the camera.

More Detail: Mirrorless cameras are often touted as being smaller and lighter than a digital SLR. However, just because a camera is mirrorless doesn’t mean it will necessarily be smaller or lighter than an SLR camera.

The fundamental difference between a mirrorless camera and an SLR is, of course, the absence of the mirror that is used to enable an optical through-the-lens viewfinder. While there is a degree of weight savings to be gained by the absence of these components, mirrorless cameras gain much of their size and weight advantage from the use of a smaller sensor size.

With a smaller image sensor a camera can employ smaller lenses to achieve the same field of view. Thus, the camera body can be smaller and the lenses can be smaller. The smaller size of both generally translates into lighter weights.

Of course, digital SLR cameras are available with a variety of different sensor sizes, which translate into varying sizes and weights. For example, a small digital SLR that uses a sensor smaller than a “full frame” digital SLR could be lighter (and use smaller lenses) than a full-frame mirrorless camera.

I think it is important to keep in mind that mirrorless cameras aren’t simply digital SLR cameras with the mirror removed. The absence of a mirror provides a variety of advantages, such as excellent continuous autofocus performance even during capture.

I think it is a mistake to seek out a mirrorless camera under the assumption it will automatically be smaller and lighter than all available digital SLR cameras. However, I do think mirrorless cameras offer a variety of advantages that go far beyond size and weight, and are therefore worth exploring. I most certainly don’t feel it makes sense to choose mirrorless versus SLR based purely on the category these cameras fall into. Rather, the specific features of individual camera models should be evaluated to find the best fit for your specific needs.

Today’s Question: I’ve been told that a digital camera can’t capture as much information as human vision. Is that true?

Tim’s Quick Answer: I would say that a digital camera can actually capture more information than normal human vision is capable of, though perception can be a bit different from this.

More Detail: I most often hear the suggestion that human vision is “better” than a digital camera in the context of high dynamic range (HDR) photography. The suggestion is that by creating an HDR image you are matching the advanced capabilities of human vision. Instead, I would say that HDR photography reproduces the illusion of human vision.

The reason we might perceive human vision as having greater dynamic range and greater depth of field than a digital camera is that our eyes are constantly adjusting in terms of exposure and focal point as we move our view around a scene.

A classic example of the limitations of human vision is illustrated by walking out of a dark movie theater into daylight. It takes a minute or two for our eyes to adjust from a dark environment to a very bright environment, which illustrates that the dynamic range of our vision isn’t really all that significant. Rather, as we move our eyes around a scene with varying light levels, our pupils adjust to effectively alter the exposure of our vision.

Similarly, as we move our eyes around a scene, our focal point changes rapidly, providing the illusion of tremendous depth of field. We actually see a very small area of a scene to be in perfect focus, both in terms of depth and field of view.

So, in general I would say that a digital camera is actually able to capture more information in terms of dynamic range and depth of field, when compared to normal human vision. The difference is that human vision is simply making constant adjustments, while a digital photo preserves a single (hopefully decisive) moment in time.