Category: Ask Tim Grey

Today’s Question: Recently I checked and found out that the option to “Show Items from Subfolders” from the View menu in Adobe Bridge was disabled and greyed out. I have been searching around on the web did not find any clue how to enable this option or why it was disabled.

Tim’s Quick Answer: I suspect in this case you are viewing search results in Adobe Bridge rather than browsing directly within a folder. When you use the search feature in Adobe Bridge, there is a separate setting for whether or not to include results from subfolders, and therefore the item on the View menu is disabled when you’re viewing search results.

More Detail: When you perform a search in Adobe Bridge, the results are displayed and at the top of the Content panel you will see a summary of the search criteria. That criteria would include, for example, whether or not Adobe Bridge is showing results from subfolders or only from the current folder.

You can change the search criteria by clicking the New Search button at the top-right of the Content panel. This will bring up a dialog, which includes a variety of controls to enable you to refine your search. One of those is a checkbox for “Include All Subfolders”.

Because there is a separate control related to subfolders when using the search feature in Adobe Bridge, the “Show Items from Subfolders” command on the View menu is disabled when you have active search results displayed within Adobe Bridge.

Note that you can click the “X” button at the top-right of the Content panel (or in the search field) to clear the search result and continue browsing individual folders directly. At that point the “Show Items from Subfolders” command would be enabled again on the View menu.

Today’s Question: Can you suggest a shutter speed that would capture the “movement” that you mention [for the Harris Shutter effect discussed in Monday’s edition of the Ask Tim Grey eNewsletter]?

Tim’s Quick Answer: Actually, when capturing individual photos to create a Harris Shutter effect the shutter speed is generally not critical, though I recommend a moderately fast shutter speed in most cases. The effect is achieved in part by capturing three photos with a delay between each capture. The change that occurs in the scene during that delay is what contributes to the final effect.

More Detail: I was a little surprised (and very delighted) at the strong interest and response I received following the question (and answer) in the Ask Tim Grey eNewsletter about the Harris Shutter effect.

As noted in yesterday’s Ask Tim Grey eNewsletter, the Harris Shutter effect is produced by combining three separate image elements into a single full-color result. The original effect was created using film in conjunction with a set of colored filters that would be positioned sequentially over the lens, but you can create the same basic result with digital captures.

A full-color RGB image is comprised of a red channel, a green channel, and a blue channel, which combine to provide all of the color information for the photo. With the Harris Shutter effect, the red, green, and blue channels are captured from the exact same scene but at slightly different times, so that any movement within the frame is rendered as a color based on the channel used for that capture.

As a result, the main determining factor of the final result is the change within the scene between the individual captures. The shutter speed can obviously play a role in how the scene is rendered and the degree of variation from one frame to the next, but you can use a fast shutter speed for your captures and still produce a very dramatic result simply by introducing a delay between the individual photos that will be used as the basis of the final image.

It is worth noting that the original effect (using a physical mechanism for the overall exposure) was created by Robert S. Harris of Kodak. You can read a bit of the background of the effect in the Wikipedia article found here:

https://en.wikipedia.org/wiki/Harris_shutter

Today’s Question: I’ve been a reader for a long, long time. I was recently reminded about a topic you discussed a while ago, and can’t remember how to create the effect. Can you remind me how to create the “Harris Shutter” effect in Photoshop?

Tim’s Quick Answer: The Harris Shutter effect can be created by capturing three photographs of a scene that contains some degree of movement, with at least a short delay between each capture and with the camera mounted on the tripod. After capturing these photos, you combine the red channel from one image, the green channel from another image, and the blue channel from a third image to create the final effect.

More Detail: The Harris Shutter effect refers to a process that involved capturing a single image with the exposure for that single capture divided between the use of a red filter, a green filter, and a blue filter. The result was an exposure where the areas of the scene without movement appeared normal, and the areas with movement showed various color effects based on the blending of the color channels.

The same effect can be created in Photoshop by combining the red, green, and blue color channels from three separate images into a single final image.

Naturally the first step is to capture three photographs of the same scene. By using a tripod, areas of the scene that don’t have any movement will be rendered the same in each photo. Areas with movement, however, will appear differently in each photo.

You can then open all three photos in Photoshop. For each photo you can then go to the Channels panel for each of the photos and choose “Split Channels” from the panel popup menu at the top-right of the Channels panel. This will create three monochromatic channels for each image, opening each of them as individual images within Photoshop.

Next, close all but one channel for each image. For one image you’ll want to close the green and blue channels in order to leave the red channel. For another image you’ll want to keep only the green channel, and for a third image you’ll want to keep only the blue channel.

When you have only one image open for a red channel, green channel, and blue channel, you can go back to the Channels panel and choose “Merge Channels” from the panel popup menu. In the Merge Channels dialog, make sure that the Mode popup is set to “RGB Color” and that the number for Channels is set to three. Then, in the “Merge RGB Channels” dialog ensure that the appropriate channels (red, green, and blue) are selected for the applicable popups within the dialog. Click OK, and the full color image will be produced, with the Harris Shutter effect created in the process.

Today’s Question: When optimizing a RAW file in Lightroom, I am aware that the typical Camera Raw tools are non-destructive. Since there are many other adjustment tools in Lightroom, am I still working with RAW data or has Lightroom converted my image to pixels at some point? If Lightroom is working on pixels, wouldn’t I be better off to take that image out to the Photoshop Editor and work in Layers?

Tim’s Quick Answer: Lightroom is working with the RAW capture data when applying adjustments to your images, but some of the adjustments are applied after the process of rendering pixel values. But ultimately I wouldn’t worry too much about the complexities of what is happening in Lightroom, and instead focus on workflow efficiency and quality of results when defining your approach to optimizing photos.

More Detail: Much has been made about the notion of applying adjustments at the time of converting a RAW capture to actual pixel values. However, many of the adjustments you might apply with RAW-processing software are actually applied to pixel data after it has been rendered from the RAW capture. In other words, for many of the adjustments you might apply there isn’t a significant advantage to applying those adjustments with RAW-processing software rather than pixel-based tools such as Photoshop.

The specific details will vary among different software that enables you to work with RAW captures, and so it can be very difficult to get a clear sense of which adjustments are being applied at which specific stage of processing your photos. Furthermore, in many cases the timing of applying those adjustments relative to RAW data versus pixel data isn’t especially critical. In other words, I wouldn’t use this issue as the key consideration in your workflow.

Instead, I would focus on workflow efficiency, flexibility of your workflow, and the results you are able to achieve.

In many cases, for example, I simply find the results I’m able to achieve with Lightroom or Adobe Camera Raw are superior to what I could achieve within Photoshop directly. Noise reduction in Lightroom and Camera Raw are superior to the filters available in Photoshop, as are the lens correction and perspective adjustments in my experience. As a result, even with images that have already been converted to pixels rather than RAW data, I’ll often use Lightroom or the Camera Raw Filter in Photoshop to apply these adjustments to my photos.

More importantly, perhaps, is the greater power and flexibility of selections and layer masks in Photoshop as compared to Lightroom and Adobe Camera Raw. Therefore, when it comes to targeted adjustments I am quick to shift my focus to Photoshop.

I do recommend trying to get the overall tonality and color fidelity optimized as much as possible when applying adjustments with RAW-processing software. For most other adjustments, I recommend focusing on which tools provides the best results in terms of quality, the best ease-of-use, the greatest flexibility, and a workflow that feels comfortable to you.

Today’s Question: You made reference to “Lightroom Web”, which is not something I’ve ever heard of. I know about Lightroom, of course, and the mobile version of Lightroom, but what is “Lightroom Web”?

Tim’s Quick Answer: There is indeed a “web” version of Lightroom you can access through your web browser. Photos you have synchronized for access from the version of Lightroom for mobile devices can also be viewed and updated on any Internet-connected computer by pointing your web browser to: https://lightroom.adobe.com

More Detail: The workflow for managing your photos in Lightroom revolves around a computer, where you can access your Lightroom catalog to organize, optimize, and share your photos. You can also access some of your photos from mobile devices that have the Lightroom Mobile app installed, as well as through a web browser.

Once you have enabled synchronization within Lightroom on the desktop, you can enable synchronization for specific collections you have created within your catalog. Those collections will then be synchronized via the Adobe Creative Cloud, so that the images and related metadata can be accessed and updated from elsewhere.

Many photographers are aware that you can install a mobile version of Lightroom on your Apple or Android mobile devices. When you sign in with your Adobe ID to Lightroom on such a device, you’ll be able to review, edit, and update the photos you have synchronized from Lightroom on the desktop.

In addition, you can access those synchronized photos from within a web browser on any Internet-connected computer. Start by pointing your web browser here:

https://lightroom.adobe.com

Then sign in using your Adobe ID, and you’ll be able to access all of your synchronized photos right there within the web browser. All updates applied via Lightroom Mobile or using Lightroom in a web browser will be synchronized back and reflected within your Lightroom catalog on the desktop.

Today’s Question: I have started using smart previews [in Lightroom] so I can do most of my editing on a mobile device or on my laptop with the photos drive detached so it doesn’t spin all the time.

When I open Lightroom with the photos drive attached, will the XMP sidecar files that have new data from Lightroom Mobile editing or from editing with the smart previews get updated automatically or do I have to do something to ensure that they get updated?

Tim’s Quick Answer: If you have enabled the option to have Lightroom automatically update the XMP sidecar files, those updates will begin as soon as the source image files are available. The Lightroom catalog will be updated based on changes made via Lightroom Mobile (or Lightroom Web) as soon as Lightroom is connected to the Internet for synchronization.

More Detail: There are now a variety of ways you can work with your images in Lightroom, including the use of a feature-limited version of Lightroom on mobile devices and the ability to work with Smart Previews in Lightroom on a computer even when the source photos aren’t available.

In terms of working on mobile devices and with Smart Previews, the Lightroom catalog will be updated to reflect the changes you’ve applied as soon as synchronization is possible. That basically means that as soon as all of the devices in question have been connected to the Internet, updates will be synchronized. So, for example, when you apply an adjustment to an image with the mobile version of Lightroom, once your mobile device and your computer have been connected to the Internet Lightroom will be able to synchronize the data.

If you want the XMP files for RAW captures (or the actual image files for other captures) to be updated in addition to the Lightroom catalog, you can enable automatic updates. To enable automatic updates, go to the Metadata tab in the Catalog Settings dialog, which can be found on the Edit menu on Windows or the Lightroom menu on Macintosh. Then turn on the “Automatically write changes into XMP” checkbox, and Lightroom will update the source images with metadata updates based on changes you apply in the Lightroom catalog.

It is important to note that not all changes you apply in Lightroom can be written out to the XMP sidecar files (or source images). In general, features that are specific to Lightroom (such as pick and reject flags, collections, virtual copies, and more) cannot be saved in this way, and will only exist within the catalog.

Today’s Question: This may be very basic, but I’ve never understood why I need to see a flashing light on my camera indicating that photos are being written to the card. What benefit does that knowledge provide?

Tim’s Quick Answer: The light you’re referring to indicates that data is being written to the media card in the camera, which serves as a reminder not to eject the card or otherwise interrupt the process of writing data. Interrupting that process can cause files (photos and videos) to be corrupted or lost.

More Detail: When you capture a photo or video on a digital camera, the resulting file does not appear instantly on the media card in the camera. While the file can generally be written to the card very quickly, sometimes a little extra time is involved.

For example, when you capture a burst of photos, the image data is first stored in a memory buffer in the camera, and then written out to the media card. If you have captured a large burst of photos it can take considerable time to write all of the files to the media card, especially if the media card you’re using isn’t particularly fast.

During the time that data is being written to a media card, it is very important not to interrupt that process. If, for example, you capture a burst of ten photos and then immediately remove the media card from the camera, you would likely find that most of the image files never made it to the media card, and those that did may very well be corrupted.

So, the flashing light on your camera that indicates data is being written to the card is really a warning not to interrupt that process.

Many (if not most) digital cameras today will continue writing data to the media card even if you turn off the camera. You may have noticed, for example, that even after turning off the camera the flashing light continues to flash. However, if you remove the media card from the camera (or in most cases even open the battery door or the media card access door) you will interrupt the process of writing data to the card, and data may become corrupted or lost.

Today’s Question: When shooting for panoramas, is there a maximum number of individual photos to include? I got this message: “Unable to merge photos, not enough matching photos for merging”. I had 25 individual photos to merge. Was this too many?

Tim’s Quick Answer: There isn’t really a limit to how many photos can be merged into a composite panorama, other than limitations related to maximum pixel dimensions, file size, and memory available when assembling that panorama. In this case the issue you’re running into is likely that the content of the photos is not distinct enough for the software to accurately combine the photos.

More Detail: When capturing the individual frames for a composite panorama, each frame must be overlapped to some degree (generally around 20% to 50% depending on the lens focal length and other circumstances). That overlap enables software to look for similar features from one frame to the next, so the images can be blended together into the final panorama.

With a typical landscape panorama the software is generally able to find matching features among the overlapping areas of each pair of photos, enabling the composite image to be assembled with relative ease. However, if there are not distinct features across the full scene you’ve photographed, it can be difficult (or impossible) for the software to merge the images.

For example, I recently captured a composite panorama that included a boat at the far left end of the scene, with nothing but water across the rest of the scene. While there was certainly a considerable amount of texture in the water and sky that represented most of the scene I was photographing, there weren’t enough distinct features that could be aligned, since the waves would have changed from one frame to the next. As a result, I couldn’t find any software that could assemble that particular panorama.

It is still possible to assemble such a panorama with a manual approach, such as by using layers and masks in Photoshop. That can still be a challenge, of course, but when you are exercising direct control over the layer masks that are being used to blend the images together, you can find ways to blend them that will work for the final result.

As noted above, assembling a composite panorama that consists of a large number of photos generally won’t be a problem. Many applications are limited in terms of the total pixel dimensions that can be used for any image, and overall file size will be limited depending on the specific hardware and software configuration. But other than these types of limitations, you can assemble composite panoramas with a large number of individual frames, including individual frames that represent multiple rows of captures for the same scene.

Today’s Question: What would you suggest for an off-site copy of “All Photographs” in Lightroom, which would fit in a safe deposit box?

Tim’s Quick Answer: To create this type of “everything” backup for photos and your Lightroom catalog, I recommend using the “Export as Catalog” command to export all photos and a catalog that contains all of the information for those photos based on the information in your existing catalog. You can export that backup copy to an external hard drive, which can be placed in a safe deposit box (or other offsite storage).

More Detail: The “Export as Catalog” command in Lightroom enables you to export a Lightroom catalog based on the photos you’ve selected for export, along with copies of all photos being managed by that catalog. The only caveat is that you need to make sure that the actual image files are copied as part of this process.

You can export every single photo and video included in your Lightroom catalog by first selecting all photos within your catalog. To do so, go to the “All Photographs” collection in the Catalog section of the left panel in the Library module, and then choose Edit > Select All from the menu to select all images in your catalog.

Next, choose File > Export as Catalog from the menu. In the Export as Catalog dialog you can navigate to the location you want to use for saving the copy of your catalog and photos, such as an external hard drive specifically intended for this purpose. If needed you can also create a folder in that storage location to encapsulate all of the files and folders that will be created as part of this process.

In addition, it is very important to turn on the “Export negative files” checkbox. This checkbox is what actually enables the source image files to be copied, in addition to the catalog file that will be created as part of this process.

There are also options to build or include Smart Previews for your photos, and to include any other available previews that have already been generated for your photos. These items aren’t critical from a backup standpoint, since you could later re-generate all of those previews if needed.

When you click the Export Catalog button, a new catalog will be created based on the selected photos (all images in your catalog in this example), and all photos and videos will be copied as well, with the same folder structure you are already using for your existing catalog of photos.

Should you ever need to recover from that backup, obviously the photos you copied would be there, but you could also open the catalog that was created as part of this process within Lightroom in order to access all of the information you had added to the catalog for those photos up to the time of using the “Export as Catalog” command. Naturally you could essentially repeat this process periodically to “refresh” the backup you’ve created for offsite storage.

Today’s Question: This may be silly, but can you tell me how you calculated the number of color values available based on bit depth?

Tim’s Quick Answer: There are two “basic” steps to calculating the number of colors available based on bit depth. First you raise the number 2 to a power based on the bit depth you’re calculating, such as raising 2 to the 8th power for 8 bits per channel. Then you take the result from step one and multiply it by itself based on the number of color channels. In other words, you would cube the result for a three-channel RGB image to obtain the number of colors available for an 8-bit per channel RGB image.

More Detail: Bit depth refers to the number of bits used to store a specific numeric value, which in this case refers to pixel values in a digital image. Each bit can have one of two values, which represent “on” or “off” and are often described as “1” and “0” in the parlance of computer systems.

When we say that a value is “8 bits” we are essentially saying that the value can be represented by an 8-digit number, but where each digit can only be “1” or “0”. So the first digit can have one of two values, and the second digit can have one of two values, and so on. Thus, we can calculate the total number of possible values for an 8-bit number by multiplying 2 by itself a total of 8 times. For different bit depths, simply repeat the multiplication based on the bit depth value (in place of 8 used in the example here).

Of course, instead of multiplying 2 by itself multiple times, you can also simply raise the number 2 to a power based on the bit depth. So, for an 8-bit number you could raise 2 to the power of 8. This function is available on many calculators as an “x-to-the-y” function, which calls for entering “2”, then pressing the “x-to-the-y” button, followed by the power you want to raise 2 to.

At this point you will have the number of possible tonal values for a single channel. For an 8-bit value that would be 256 shades of gray for a black and white image. But for a typical RGB color image there are three channels (red, green, and blue). Therefore, you need to take the result you got from the first step and multiply it by itself based on the number of channels. So in this example you could multiply 256 by 256 by 256 (for a total of three instances of 256, if you will). That also translates into cubing the value.

So, completing our example here, 256 raised to the power of 3 produces a result of 16,777,216 possible color values for an 8-bit per channel RGB image. Keep in mind, of course, that this is only the theoretical maximum number of colors available, and the actual number represented in a given photo could be significantly lower.