Category: Ask Tim Grey

Today’s Question: I made a selection in Photoshop CC and then added an adjustment layer. Everything looks fine, and the layer mask shows what I expected. I made a selection again and then used Quick Mask mode to modify the selection. When I added an adjustment layer, this time there is no layer mask. What am I doing wrong?

Tim’s Quick Answer: This is a matter of selections being treated differently in Photoshop depending on whether you are in Quick Mask mode or the “normal” selection mode. After using Quick mask mode to refine your selection, you can switch back to “normal” selection mode before adding the adjustment layer and the layer mask will reflect your selection.

More Detail: A common approach to applying a targeted adjustment to a photo in Photoshop is to first create a selection of the area you want to adjust, and then add an adjustment layer. The layer mask associated with the new adjustment layer will automatically reflect the selection that was active, so that the adjustment only affects the area that had been selected.

When you are in Quick Mask mode making changes to a selection, however, this behavior changes. If you add an adjustment layer while in Quick Mask mode, the layer mask associated with the new adjustment layer will not reflect the active selection. Instead, there will be a “blank” (all white) layer mask, meaning the adjustment layer will affect the entire image.

The workaround is to make sure you are in the “normal” selection mode before adding an adjustment layer (or otherwise adding a layer mask). You can still use Quick Mask mode to modify your selection, of course. But then when you’re finished you can exit Quick Mask mode (by pressing “Q” on the keyboard) to ensure you’re in the normal selection mode before adding an adjustment layer or otherwise adding a layer mask to an image.

Today’s Question: I have come across several images that have received extensive editing and now are marked with an arrow icon in the upper right corner of the image in the grid view. When I click on this icon I get a message I don’t understand:

“The metadata for this photo has been changed by both Lightroom and another application. Should Lightroom import settings from disk or overwrite disk settings with those from the catalog?”

I assume that this may be the result of editing in Lightroom after editing in Photoshop, but I’m not sure. I’m also at a loss as to what the different outcomes of the choice I’m being asked to make.

Tim’s Quick Answer: The message indicates that changes have been made to the metadata for a photo outside of Lightroom, which in turn means that the embedded metadata for the photo does not match the metadata in the Lightroom catalog. The options presented to you are asking you to choose which metadata you want to keep, and therefore which metadata you want to lose, in order to synchronize the metadata between the image and the catalog.

More Detail: There are a variety of ways the metadata in an image file might get updated so that it no longer matches what Lightroom is expecting based on the information about a photo in the Lightroom catalog. For example, if you browse a photo in Adobe Bridge and add a keyword, that keyword would not be reflected in the Lightroom catalog. As a result, there would be a metadata mismatch.

In general you can avoid these types of mismatches by making sure that everything you do with an image is initiated in Lightroom. If you always make a point of performing all updates in Lightroom, it will also be easier to know which option to select if a metadata mismatch should occur.

The options available to resolve a metadata mismatch in Lightroom involve choosing which metadata you want to keep and which metadata you want to lose. Unfortunately, it isn’t possible to simply merge all of the updates that might have been applied within Lightroom versus outside of Lightroom.

Let’s assume you have a photo of a bird captured in Florida. If you add the keyword “bird” in Lightroom and the keyword “Florida” in Bridge, you will have a metadata mismatch. In Lightroom you’ll see “bird” as a keyword, but not “Florida”. And in Bridge you’ll see “Florida” as a keyword but not “bird”. To resolve the metadata mismatch you will have to choose which of those keywords you want to keep.

Choosing the “Import Settings from Disk” option means that you want to retain the metadata added outside of Lightroom, and bring that metadata into Lightroom. In the process you’ll lose some of the metadata in Lightroom since it will be updated with outside values. If you choose the “Overwrite Settings” option you’ll preserve the metadata in Lightroom and save that information to the image file, replacing the metadata that had been included in that file.

Again, if all of your metadata updates have been applied within Lightroom, you can be reasonably confident that any mismatches are not critical. That, in turn, would mean that you could always choose the “Overwrite Settings” option to resolve the metadata mismatch by prioritizing the information in your Lightroom catalog.

Today’s Question: In Lightroom if you edit a raw file and save as JPEG I understand the edits are nondestructive to the original raw file. If you then re-edit the JPEG, are the new edits destructive to the JPEG file?

Tim’s Quick Answer: All of the adjustments in the Develop module in Lightroom are non-destructive to the source image file you are currently working on. That includes JPEG images (among other supported file formats) in addition to raw captures.

More Detail: When you apply an adjustment to an image in Lightroom’s Develop module, the changes you apply aren’t actually altering the source image file on your hard drive. Instead, your adjustment settings are essentially metadata updates stored in the Lightroom catalog. This approach ensures Lightroom will be non-destructive to the information in your source images.

When you export an image, you are creating a new file and the adjustments you applied will be incorporated into the pixel values for that image. So, for example, if you export a JPEG image based on a raw capture you’ve adjusted in Lightroom, the source raw file remains unchanged, but the JPEG will reflect the adjustments you applied.

If you import that JPEG image into your Lightroom catalog, you can of course apply new adjustments to that image. Those adjustments will still be non-destructive, meaning the source JPEG image file on your hard drive won’t be altered based on the new adjustments you applied. Of course, if you create a new JPEG based on the existing JPEG using the Export feature, the adjustments will be incorporated into the pixel values for that new JPEG version of the image.

So, in a way, you can think of the adjustments in Lightroom as always being only metadata updates that are non-destructive to the source image. However, exporting a new copy will cause the adjustments to be incorporated into the pixel values for the new image file created as part of that process.

Today’s Question: I frequently share JPEG images online. Periodically I want to apply some quick edits to these images before posting them, so I will open them in Photoshop. I apply my edits, and then save and close. However, if that edit includes a crop, then when I choose Save I am presented with the Save As dialog. Do you have any idea why this is happening?

Tim’s Quick Answer: You are being prompted with the “Save As” dialog because you have the “Delete Cropped Pixels” checkbox turned off. You can avoid the “Save As” dialog in this scenario by either turning the “Delete Cropped Pixels” checkbox on before cropping, or by selecting Layer > Flatten Image from the menu after cropping.

More Detail: When you turn off the “Delete Cropped Pixels” checkbox on the Options bar for the Crop tool and then apply the crop, the Background image layer will be converted to a “normal” layer. With this option the pixels aren’t actually removed from the image when you apply a crop. Instead, the canvas size is reduced to hide the cropped pixels. This requires a “normal” layer rather than a Background layer.

When you have any layers beyond a Background image layer (including adjustment layers, additional image layers, or a Background image layer that has since been converted to a “normal” layer), you can only save the image in a file format that supports layers. The JPEG file format is not one of those options. Instead, you would need to save the image as a TIFF file, a Photoshop PSD file, or a Photoshop PSB file (for images beyond the 30,000 pixel per side limit).

To enable you to save the image as a JPEG after the crop, you have two basic options. The first is to use the Layer > Flatten Image command to ensure there are no layers other than the Background image layer. The second option is to make sure the “Delete Cropped Pixels” checkbox is turned on before applying the crop in this type of scenario. I do, however, recommend turning that option back on when you’re done, assuming you normally prefer to apply a “non-destructive” crop to your photos.

Today’s Question: How can I make a borderless print in Lightroom? When I try to reduce the margin settings, I’m not able to go below 0.13 inches for all four sides of the print. How can I set the margins to zero?

Tim’s Quick Answer: To print borderless from Lightroom Classic CC you actually need to select one of the borderless paper options first. These options can be found in the Page Setup dialog.

More Detail: With the default paper options, you aren’t able to produce a borderless print in Lightroom. Instead you will be limited in setting the margins based on the capabilities of your printer for a non-borderless print. These limits are often in the vicinity of 0.25 inches on each side of the print.

In order to be able to reduce the margins to zero, you need to select a borderless paper option. Start by clicking the Page Setup button at the bottom of the left panel in the Print module. In the Page Setup dialog, make sure the correct printer is selected from the Format For popup.

Then click the Paper Size popup, where you can choose the specific size of the paper you’ll be printing to. For many of the available paper sizes there will be various options on a submenu. Among those, for supported paper sizes, you will find one or more “Borderless” options. You’ll see borderless options for “Auto Expand” and “Retain Size”. I recommend selecting the “Auto Expand” option for the applicable paper size to ensure there won’t be a small blank margin around the print, which may appear if you choose the “Retain Size” option.

Once you’ve selected the appropriate paper size option you can click the OK button to close the Page Setup dialog. You’ll then be able to set the margins on all sides to zero, and set the Cell Size settings to the full size of the page, so you can produce a borderless print.

Today’s Question: When I see yellow flowers with the naked eye, I see them as having more lemony, light yellow overtones. But when I photograph them I see they usually turn out with more orange overtones and it seems difficult to capture their natural color from the start. Seems I always am fiddling with Lightroom temperature and exposure adjustments to try to make the yellows look natural. I have similar challenges when I photograph reds. And, not only do I have temperature issues, it seems difficult to capture details. Any advice?

Tim’s Quick Answer: There are two key issues here. One is a color temperature that isn’t quite right, and the other is an exposure that is too bright for at least one of the channels for the image. I suggest starting with a custom white balance setting for this type of scenario, and checking your exposure carefully using histograms for individual color channels rather than only for overall luminance.

More Detail: In theory the accuracy of color in a raw capture isn’t critical, as you can always fine-tune the Temperature and Tint adjustments in post-processing. With a raw capture, if you apply those color adjustments as part of the original processing of the raw capture then there is no penalty in terms of image quality.

Of course, in many cases you may want to ensure the color in the original capture is as accurate as possible, so that you have a better starting point in post-processing. A custom white balance setting in the camera can help with this.

The specifics of implementing this option will vary from one camera to the next, but in general the process involves taking a picture of a neutral subject (such as a blank sheet of paper or a gray card) under the same lighting as the subject you’ll photograph. Then set that image as the reference photo for a custom white balance setting within the camera. Set the white balance preset to the appropriate “custom” setting, and the color will be adjusted based on the color of the light for subsequent captures.

This does mean the beneficial influence of color (such as golden light in the late afternoon) will be neutralized, which isn’t always ideal. But with this approach you’ll have a more accurate starting point for your color. The result will be as though the subject was illuminated by pure white light.

As for the loss of detail for key colors, this generally means that one (or two) color channels has been over-exposed. This is just like clipping highlights to pure white, except that it doesn’t involve all three channels.

So, for example, if the red channel is over-exposed, you’ll lose texture and detail in a photo of a red rose. The solution is to reduce the exposure so that all three color channels show no clipping for the highlights. To evaluate this I recommend setting your camera to display a “full color” histogram that displays an individual histogram for each of the three color channels (red, green, and blue). This level of detail can’t easily be determined with a luminance histogram that is based on brightness values for the overall image.

Today’s Question: When preparing photos for a PowerPoint show where the quality of the images is important (for showing off the photos to their best) and around 150 photos or more, what would you recommend for file size?

Tim’s Quick Answer: The key for a digital presentation such as a slideshow is to make sure the images are sized based on the pixel dimensions of the display you will be using. You can then save the images as either PNG (Portable Network Graphics) files, or as JPEG images with the Quality set at or near the maximum value.

More Detail: The actual file size for images that will be presented on a digital display (such as in a slideshow presentation) doesn’t tend to be a critical concern, in large part because by definition those files won’t be extremely large.

The first thing you’ll want to do is confirm the resolution of the display you’ll be using for the presentation. In many cases you’ll still find projectors in use with a relatively low resolution of around 1024×768 pixels, or perhaps full HD resolution of 1920×1080 pixels. Of course, you might also have the opportunity to present on higher-resolution displays, such as a 4K display that will have a resolution of around 4,000 pixels wide.

Based on the display, you can then resize the copies of images to be used in the presentation to a size that is at or slightly above the expected resolution. I then prefer to save in the PNG file format if that is supported by the software you’ll use for your presentation. PNG files will generally offer at least slightly improved quality over JPEG images, because the PNG format uses lossless compression. The file sizes will be larger than a JPEG image in most cases, but for a digital slideshow that isn’t a significant concern.

If the software you are using for the presentation doesn’t support PNG files, you can save the images as JPEG files with the Quality setting at (or near) the maximum value. This will still provide good image quality, with a file size that is generally smaller than the PNG file would have been.

Today’s Question: In a recent answer you said about JPEG file sizes: “with variation based on the actual contents of the image”. What do you mean by that? Wouldn’t the file size be based only on the pixel dimensions and the quality setting used.

Tim’s Quick Answer: The file size of a JPEG image is primarily determined by the pixel dimensions and the quality setting. However, the specific file size result will vary based on the complexity of information in the image file. In other words, the more variation there is in pixel values, the larger the file size is likely to be.

More Detail: JPEG compression operates by dividing the image up into blocks of pixels and simplifying the information within each block. For example, an image would typically be divided into blocks of 256 pixels (16×16 pixels in a block). Within each block, the pixel values are simplified.

For example, let’s assume that in a given block all 256 pixels are pure white. With no compression at all, you essentially would need to say “white” 256 times to describe the contents of the block. But it would be much more efficient to simply say “256 white pixels”.

In a similar way, JPEG compression will alter the pixel values within each block in order to be able to describe the pixel values more efficiently, resulting in a smaller file size.

For my example of 256 white pixels, the information can be described with great efficiency, so that block would represent a smaller file size. If, on the other hand, there was tremendous variation within a block of pixels, it isn’t as easy to simplify the contents of that block without further degrading image quality. That would result in a larger file size.

So, with an image at a particular size in terms of pixel dimensions, and with a specific quality setting for the JPEG compression, the file size can still vary considerably for different photos based on the actual contents of the image.

Today’s Question: When exporting a raw, TIFF, or PSD file as a JPEG from Lightroom, you may need to reduce the output JPEG file size for sending via e-mail for example. You can reduce the JPEG quality, or you can specify a maximum file size, or you can resize the image and specify the resolution. For the equivalent JPEG file size, which of these approaches give the best quality JPEG image?

Tim’s Quick Answer: When creating a JPEG image, the pixel dimensions primarily determine the potential output size, and the Quality setting determines the amount of quality degradation caused by compression. Both are important, but I would make it a priority to use a relatively high Quality setting (about 80% or above).

More Detail: The pixel dimensions determine how many pixels are included in the JPEG image you’re exporting. That, in turn, determines how large the image can be displayed or printed. When printing the image can certainly be enlarged to a degree, but an extreme enlargement can result in poor print quality.

The Quality setting relates to compression applied to the image in order to reduce file size. Even at a relatively high Quality setting, the file size will be relatively small. But if you use a setting for Quality that is too low, compression artifacts may be visible in the image.

I recommend taking a balanced approach. For printing you’ll need to determine the pixel dimensions required for the intended output. For digital displays, you can set pixel dimensions that will provide an adequate display size based on how the image will be displayed. For a typical monitor display, for example, I’ll generally resize the image to about 2,000 pixels on the long side. I’ll then typically use a Quality setting of 80%. This provides an image of very good quality for a digital display, with a file size that is generally around 1MB or so (with variation based on the actual contents of the image).

Note, by the way, that the pixel per inch setting is not critical and does not impact file size. This is simply a setting that determines the print resolution. It does not affect the image appearance on a digital display.

Today’s Question: Is “native” ISO synonymous with “base” ISO? Is there only 1 “native” ISO?

Tim’s Quick Answer: No, native and base ISO are not necessarily the same thing. A native ISO is an actual amplification setting in the camera that does not require interpolation in processing. The base ISO is the lowest of the native ISO options.

More Detail: Digital cameras offer a wide variety of ISO settings. However, in many cases the options available are not truly “native” options. What that means is that the camera essentially doesn’t have all of the ISO settings you can choose from as built-in amplification options. Instead, the capture data needs to be interpolated to calculate pixel values for non-native ISO settings.

For example, you may be able to select an ISO setting of 160 on your camera. But chances are, the only native ISO settings in that range are 100 and 200. To calculate the pixel data for 160 ISO, the camera could expose based on 200 ISO and then interpolate the data to achieve a final exposure based on a 160 ISO setting.

In many cases a camera will offer native ISO settings in one-stop increments, such as 100, 200, 400, and so on. Values in between are generally non-native, being calculated based on interpolation.

The point is that a camera will generally offer multiple native ISO settings. The base ISO setting is simply (in most cases) the lowest of those native ISO options.