Category: Ask Tim Grey

Today’s Question: As a photographer who currently uses the Lightroom Library module to manage my photo files and use Photoshop and Photoshop Elements as the only other Adobe software. As part of the Adobe CC Photographer package, I see that I am entitled to download and install Adobe Bridge. But since I’m not transferring any files to any other Adobe software, is there any advantage or reason for me to download and install it?

Tim’s Quick Answer: Not really. Some photographers find it easier in certain situations to launch Adobe Bridge (rather than Lightroom) when they want to quickly browse some of their photos. But I find it just as fast (and sometimes faster) to make use of Lightroom, and so I don’t feel any need to have Adobe Bridge installed.

More Detail: One of the advantages of using Lightroom to manage your photos is that you have a central catalog that speeds up the process of filtering images. In addition, if you have Standard (or 1:1) previews generated upon import for all of your photos, you can browse among various photos quickly in Lightroom.

Bridge, by comparison, is a browser without a central catalog (though it does make use of a cache, which provides a degree of benefit in terms of performance in certain situations). As a result, it can take longer in Adobe Bridge to browse among folders and especially to filter images within the folder, because for each folder you navigate to Bridge will need to analyze the images to determine which photos contain which specific metadata values.

There are some potential advantages to using Adobe Bridge if you work among a variety of different Adobe applications, such as InDesign for creating documents and Illustrator for creating illustrations. But if your workflow revolves around photos and you are using Lightroom to organize your photos, in my mind there is no reason to install Adobe Bridge.

If you do choose to make use of Adobe Bridge, I highly recommend that you avoid applying any metadata updates using Adobe Bridge, as that can lead to confusing mismatches of metadata values between Adobe Bridge and Lightroom (or more specifically, between the metadata in your photos and the metadata in your Lightroom catalog).

Today’s Question: I just returned home from 10 days in Costa Rica and realized only now (while reading Ask Tim Grey) that I forgot to reset the date and time on my camera to Costa Rica time. Is there any way to fix this now, after I’ve already uploaded the images to Lightroom?

Tim’s Quick Answer: You can most certainly update the capture time in Lightroom after you’ve imported your photos into your Lightroom catalog. Simply select the photos and then choose Metadata > Edit Capture Time from the menu. Choose the “Shift by set number of hours” option, set the appropriate time difference, and click Change to update the capture time for the photos.

More Detail: It is important to keep in mind that by default when you update the capture time in Lightroom you are only updating the capture time in metadata within the Lightroom catalog. In other words, if you browse your photos using software other than Lightroom (such as Adobe Bridge), you’ll still see the incorrect capture time.

However, you can update the settings in Lightroom so that the capture time for your original capture is updated when you use the Edit Capture Time command. There is a small degree of risk that in the process of updating the capture time for your original captures that the files will be corrupted. However, I’ve never heard of a situation where this process created any problems with the original photos. But again, there is some risk involved.

To change the setting so Lightroom will apply the capture time adjustment to the actual source photos, start by choosing Lightroom > Catalog Settings from the menu on the Macintosh version of Lightroom or Edit > Catalog Settings from the menu on the Windows version of Lightroom. This will bring up the Catalog Settings dialog. Choose the Metadata tab, where you can turn on the “Write date or time changes into proprietary raw files”. Close the Catalog Settings dialog, and from this point forward when you apply changes to the original capture time those changes will be reflected both in your Lightroom catalog and in the original files for your photos.

Today’s Question: I know this should be simple, but I can’t get Lightroom to move photos to a different folder using drag and drop. I know it is possible to move photos, since you’ve written about this very task. But when I drag and drop with several photos selected, the photos don’t move and then only one photo is selected. Is this a bug or am I doing something wrong?

Tim’s Quick Answer: To drag and drop photos within Lightroom you need to click (and drag, of course) on the thumbnail for one of the selected photos, not on the frame around the photo.

More Detail: The issue here relates to the difference between clicking on the actual thumbnail of the photo and clicking on the frame around the photo. Clicking on the frame will cause the image contained within the frame to be the only image that is selected, causing all other photos that had been selected to be deselected.

Thus, when you have multiple images selected in Lightroom and you want to drag those photos to a different location (or to a collection) it is important to click on the thumbnail for one of the selected photos rather than the frame around the photo.

Today’s Question: I have three versions of Photoshop (CS2, CS3, and CS6). All of a sudden I have only crosshairs for the mouse pointer for all of my tools. I had this happen years ago but I cannot find what to do to get back to “normal”.

Tim’s Quick Answer: All you need to do is press the Caps Lock key on the keyboard. This keyboard shortcut serves as a toggle between the “brush shape” mouse pointers (generally a circle, for example) and the “precise” option (crosshairs).

More Detail: This is a common source of confusion when you turn on (or off) the Caps Lock option and don’t realize it also impacts the display of the pointer for your mouse. Note that you can also adjust the specific settings for the mouse cursors by going to the Cursors page of the Preferences dialog. You can find the Preferences option on the Edit menu on the Windows version of Photoshop or the Photoshop menu on the Macintosh version of Photoshop.

It is also worth noting that if the brush is too small or too large to display as a circle (for example), then the cursor will also display as a crosshair rather than the brush shape. So, if pressing the Caps Lock key on the keyboard doesn’t solve the issue of seeing a crosshair when you expect to see a brush shape, make sure the brush size is not too large or too small.

Today’s Question: I was watching a presentation about Lightroom and when the presenter moved from one image to the next, exposure information appeared briefly over the photo. I would like to enable this option but for the life of me can’t find it. Can you tell me how to enable this option?

Tim’s Quick Answer: The “trick” here is to turn on the “Show briefly when photo changes” checkbox for one of the Loupe Info options in the Library View Options dialog, which you can find by choosing View > View Options from the menu bar.

More Detail: The information display you’re referring to is the Info Overlay for the loupe view, which you can display (or hide) by pressing Ctrl+I on Windows or Command+I on Macintosh. If you want the info to appear briefly each time you switch to a different image, you can configure that option in the Library View Options dialog. To do so, select View > View Options from the menu and click the Loupe View tab. Make sure the “Show Info Overlay” checkbox is turned off, and then turn on the “Show briefly when photo changes” checkbox for Loupe Info 1 or Loupe Info 2.

More Detail: By turning on the “Show briefly when photo changes” checkbox for Loupe Info 1 or Loupe Info 2, the information for the applicable info option will appear briefly each time you switch to a different image, rather than having to toggle the display of the information manually.

Note that you can also adjust the specific information included with the two Loupe Info options. Each of the Loupe Info options includes three popups, where you can select specific information to be displayed based on the metadata for the current image.

Today’s Question: I have a client that hires me to do some product photography, where the colors of their products need to be very accurate based on specific RGB values. I know I can see the color values for a given area by opening the Info panel in Photoshop and moving my mouse over the area. But as soon as I move my mouse back to make changes to my adjustment, the Info panel numbers disappear. Is there a way to keep the numbers visible while I’m working on adjusting the color?

Tim’s Quick Answer: The solution to this issue is to place one or more color samplers on the image so that you can view the values for those samplers on the Info panel. Start by clicking and holding the mouse button down on the button for the Eyedropper tool on the toolbox to bring up a flyout menu, where you can choose the Color Sampler tool. Then click on the image in the areas you want to evaluate, adding up to ten color samplers (up to four with older versions of Photoshop. You can then view the value for each of those color samplers on the Info panel.

More Detail: When you are using color samplers on your image to adjust pixel values within the image, the values shown for each color sampler on the Info panel will have two values for each of the color channel when you are applying an adjustment. The value to the left is the “before” value, before your adjustments were applied. The value to the right is the “after” value. So you’ll want to pay attention to the values on the right for each color sampler shown on the Info panel as you apply your adjustments aimed at achieving specific color values.

Note that when you’re finished working with the color samplers you can remove them from the image. To do so, first make sure the Color Sampler tool is active. Then hold the Alt key on Windows or the Option key on Macintosh, and click on the color sampler in the image to remove the color sampler. Note that the mouse pointer will show a pair of scissors when you are holding the Alt/Option key and hover the mouse over a color sampler.

Today’s Question: In a recent eNewsletter you stated that in camera “With most cameras each individual ‘pixel’ on the image sensor is only recording a single color value (generally red, green, or blue)”. Can you expand on this and explain how we end up with all three color values for each pixel from such slim camera data?

Tim’s Quick Answer: There are certainly exceptions, but with most digital cameras the image sensor uses a sensor where each “pixel” is only recording a single color of light. Essentially each photosite on the sensor has a colored filter in front of it, so each photosite records only red, green, or blue light. Either in the camera (in the case of JPEG capture) or in post-processing (with RAW capture) the “other” values are calculated based on surrounding pixel values.

More Detail: It might seem a little outrageous that two-thirds of the information in a digital photograph is created after the capture, but it is true for the vast majority of digital camera sensors. And I can make the situation sound even worse.

The red, green, and blue photosites on the image sensor aren’t distributed in equal quantities in most cases. On a typical sensor half of the photosites are capturing green light, one-quarter are capturing red light, and one-quarter are capturing blue light. This is because the green light represents the most prominent light in the scene based on nature of human vision. One way to think of this is to consider that in an RGB image, the green channel will most often represent the best black and white image if you could only choose among the three channels to create a black and white image.

So, how is that “extra” information created out of thin air? To be sure, the process is complicated and there are many advanced algorithms at work behind the scenes when processing a RAW capture. But in basic concept it isn’t actually too complicated.

Instead of thinking about the final color photograph, think about the individual channels that comprise that color image. Each of the channels (red, green, and blue) are black and white images that reflect how much red, green, or blue light should be combined to create the color value for each pixel. You can get a sense of this by viewing the individual color channels for a color image using the Channels panel in Photoshop.

Imagine a black and white photo, consisting of many shades of gray. Now imagine that every other pixel is blank. That is what the unprocessed green channel looks like for a RAW capture, in terms of the image sensor only recording green light for half of the pixels on the image sensor. The software simply (I use the term loosely) needs to calculate the missing values in between each green pixel value. In theory you could just fill in the blanks with the average of the two adjoining pixel values, but of course in the real world the math is far more complicated.

Keep in mind also that besides having half of the pixel values for the green channel, the software processing a RAW capture also has red and blue values for the surrounding pixels. So there is a reasonable amount of information to provide an ability to infer pixel values.

Of course, for the red and blue channels the situation is a little more challenging, since fully three-quarters of the information is “missing” for those channels. But the same basic process applies (with complicated math in the background) and the “other” color values for each pixel can be calculated.

To be sure, in the early days of digital capture the task of “filling in the blanks” (a process that is generally referred to as demosaicing, by the way) wasn’t performed very well. Over the years the software for RAW processing has gotten much more advanced. This enables the initial color information to be calculated more accurately than was the case with earlier software, and it also means that greater detail and sharpness can be preserved.

I suppose it would be fair to say that in simple concept, the task of demosaicing is relatively straightforward. You “simply” need to fill in the blanks based on what you can infer from surrounding pixel values. But, of course, the math behind this processing is quite complicated. Thank goodness there are very smart software engineers who have tackled this task and provided us with a variety of high-quality RAW-processing software!

Today’s Question: Are high-speed bursts typically written to CF and SD cards out of capture order? I sometimes shoot sports action with a Canon 1D X (using 90 MB/s CF) or people in motion with an Olympus E-M1 (80 MB/s SD). When I convert the raw files — captured at 10 fps — to dng and upload them to Lightroom specifying a numerical sequence, they often sequence out of capture order. For example, in a horse-racing burst the lead horse in frame #20 is clearly farther along the track than in frame #21. Or a person crossing the street will appear to have taken two steps backward from frame #5 to frame #6. What’s going on here?

Tim’s Quick Answer: I’ve only seen this behavior a small number of times, and have not been able to determine whether it is an issue with Lightroom or if it is perhaps an issue with how the images were written to (or read from) the media card. However, you can solve the issue by renaming after (rather than during) import with the sort order set to “Capture Time”.

More Detail: It is altogether possible that the camera is writing the images to the card in the incorrect sequence, especially with burst capture. Cameras generally write each new capture to the camera’s buffer first, and then transfer each image from the buffer to the media card. The images are written in the order they are captured, but I’m sure with high-speed capture it is possible the buffer might write images out of order.

I’ve also seen some indications (which I’ve never been able to verify) that Lightroom sometimes imports photos in the wrong order. This seems to be an inconsistent behavior, and it is also possible that the issue actually lies with the card and not Lightroom.

In any event, you can work around this issue by saving the renaming for after the import rather than during the import. Simply import the photos with the renaming option turned off, and then sort the imported images based on Capture Time. You can then select all of the images, make sure you are in the Library module, and choose Library > Rename Photos from the menu to initiate the file renaming using the same settings you would have otherwise used during import.

Today’s Question: When I take a 40MB DNG file from Lightroom to Photoshop, the resulting TIFF file is 207MB. Why does the file size increase by a factor of five and is there some way to reduce the TIFF file size?

Tim’s Quick Answer: There are three basic factors at play here. First, if the Adobe DNG file was created from a proprietary RAW capture format (or was a DNG capture out of the camera), the image data within the DNG file only contains one-third of the total information in terms of pixel values (more on this in a moment). Second, the DNG format uses compression that typically results in a file size that is around 20% smaller than the original RAW capture. Third, the image sent to Photoshop was likely created as a 16-bit per channel image, which doubles the base file size.

More Detail: As you may already be aware, a RAW capture only includes one-third of the total pixel information for the image. There are exceptions and variations here, but with most cameras each individual “pixel” on the image sensor is only recording a single color value (generally red, green, or blue). Part of the process of converting the original RAW capture to a “real” image involves calculating the full color value for each pixel. The result is that the RAW capture is generally about one-third of the file size of the final image, all other things being equal.

The DNG format makes use of lossless compression that results in files that are generally smaller than the original RAW capture, assuming the DNG file was created from a proprietary RAW capture. On average I find that this compression results in a DNG file that is about 20% smaller than the original RAW capture, but your results may vary.

The original RAW capture would contain information based on either 12-bit, 14-bit, or 16-bit per channel information, depending on the specific camera. Once you convert the original capture to a pixel-based format, you have the option of rendering the image in either the 8-bit or 16-bit per channel mode. The 16-bit per channel mode image will be twice as large as the 8-bit version, all other things being equal.

Finally, there is the potential for applying compression to the TIFF image, which results in a smaller file size. For example, you can make use of LZW or ZIP compression for TIFF images created by Lightroom as part of the process of sending a photo to Photoshop. Both of these options provide lossless compression that reduces the size of the image file without any reduction in image quality.

In this case, based on the information you’ve provided, I would guess that the TIFF image is being created in the 16-bit per channel mode, with LZW (or ZIP) compression enabled. In that case, the only real option for reducing the file size (other than reducing the pixel dimensions) would be to create the TIFF file as an 8-bit per channel image rather than a 16-bit per channel image. However, this would also result in less overall information in the photo, and a higher risk of some degree of posterization in the image.

On the assumption that you want to retain the full pixel dimensions of the image, and that you want to keep the image in the 16-bit per channel mode, the only other option for reducing the file size is to be sure to make use of LZW (or ZIP) compression for the TIFF file. These options can be found in the External Editing section of the Preferences dialog in Lightroom.

Today’s Question: I’m still using Adobe Bridge to manage my photos, as it works well for me. One issue I have run into, however, relates to searching for photos in subfolders. If I have been to the same place several times I make a folder for the place, and then a subfolder for each trip within that folder. Is there any way to search for images matching specific criteria (such as keywords) within all of the subfolders at once, rather than searching in each subfolder one at a time?

Tim’s Quick Answer: Yes, you can filter images across all of the subfolders below the currently selected folder (or even across an entire hard drive). Start by selecting the parent folder containing the subfolders you want to search. Then go to the menu bar and choose View > Show Items from Subfolders. This will cause the images from subfolders to be shown along with those from the current folder, and you can then set filter criteria on the Filter panel to filter among the full set of photos that are now displayed.

More Detail: It is important to keep in mind that because Adobe Bridge is a browser that does not make use of a central catalog for managing photos, the process of browsing and filtering images across multiple folders (or across an entire hard drive) can be a bit slow.

This performance issue is one of the key reasons I favor Lightroom over Adobe Bridge for managing my photos. Because Lightroom makes use of a central catalog, you are able to filter images across many folders much more quickly.

That said, you can indeed browse across multiple subfolders and set filters based on those multiple folders by making use of the “Show Items from Subfolders” option on the View menu.