Why Unsharp Mask?

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Today’s Question: You said, “in some cases it may be preferred to use the Unsharp Mask filter instead” [in yesterday’s Ask Tim Grey eNewsletter]. Why would you ever choose Unsharp Mask over Smart Sharpen in Photoshop?

Tim’s Quick Answer: The primary reason you might choose to use the Unsharp Mask filter rather than Smart Sharpen in Photoshop is to avoid adding the appearance of noise in smooth areas. While the Smart Sharpen filter is relatively “smart” in this regard, it is lacking the Threshold control that is available with the Unsharp Mask filter.

More Detail: I often describe sharpening as a process for adding contrast where contrast already exists. For example, texture in a photo is created by variations in pixel values. Sharpening involves enhancing those variations to create greater contrast and therefore a stronger appearance of sharpness.

While that sharpening effect is generally a very good thing, it can also cause smooth areas to appear a bit noisy. Even smooth areas will generally have some degree of variations among individual pixel values, and sharpening will exaggerate that fine texture to some extent.

The Smart Sharpen filter generally does a pretty good job in this regard, but it can still fail to protect smooth areas as much as is possible with the Unsharp Mask filter.

As a general rule I use the Smart Sharpen filter in Photoshop to apply sharpening to my images. However, when the image includes very smooth areas (such as a clear sky) that I want to preserve, I’ll scrutinize those areas when previewing the Smart Sharpen effect. If the result is problematic, I’ll cancel and switch to the Unsharp Mask filter.

With the Unsharp Mask filter, increasing the value for the Threshold setting will prevent the sharpening effect from being applied to areas with very minor variations in tonal values. In most cases a value of around 8 or so for Threshold will mitigate the sharpening effect adequately in smooth areas. You can start there and fine-tune as needed so that sharpening is applied where it is needed but does not create problems in smooth areas of your photos.

Color Shift from Sharpening

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Today’s Question: Is it true that sharpening can create color artifacts in photos? If so, is there a way to avoid this issue in Photoshop?

Tim’s Quick Answer: Yes, sharpening can create artifacts similar to color noise. You can compensate for this issue in Photoshop by using the Fade command in conjunction with the Luminosity blend mode.

More Detail: There are actually a couple of approaches you could use to prevent or compensate for the appearance of colored artifacts caused by applying a sharpening filter to an image. For example, some photographers convert the image to the Lab color mode and then apply sharpening to the “L” (luminance) channel.

In general I find it is simpler and easier to use the Luminosity blend mode in conjunction with the Fade command. This command can be used immediately after you have applied sharpening.

The first step, of course, is to apply sharpening to your image. I generally recommend the Smart Sharpen filter in Photoshop for this purpose, but in some cases it may be preferred to use the Unsharp Mask filter instead.

Once you’ve applied the desired sharpening to the image, go to the Edit menu and choose the Fade command. Note that this menu item will include the name of the filter you just applied, such as “Fade Smart Sharpen”.

When you select the Fade command, the Fade dialog will appear. The “normal” use of this command is to reduce the strength of the effect you most recently applied. In the case of sharpening you would generally not want to use that option, and so you would keep the Opacity setting at the maximum value of 100%.

However, in this case you do want to change the behavior of the sharpening filter you used, so you can change the blend mode to “Luminosity” using the Mode popup. This blend mode will cause the sharpening filter effect to only adjust the luminance values in the image, not the color values. The result is to mitigate any color variations that may have been introduced by sharpening.

The color variations introduced by sharpening are generally at the individual pixel level, and are not typically too extreme. However, for an image that is being printed at a large size, or for which sharpening creates visible color variations that appear as color noise especially along high contrast edges, the color artifacts can be a problem. Fortunately, the Luminosity blend mode applied through the use of the Fade command provides an excellent solution.

Independence from Lightroom

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Today’s Question: I shoot in RAW, use Lightroom to edit my photos, but don’t want to be dependent either on my Lightroom catalog or even on the Lightroom application to access my photos. I import my RAW captures into Lightroom, make my desired edits, and then export both JPEG and DNG files (checking the “Embed Original Raw File” and unchecking the “Use Lossy Compression” options when exporting the DNG file). I then delete the original RAW file.

I can now print from or make additional edits to my image using the DNG file on any computer in any application that supports the DNG file format without needing to access either my Lightroom catalog or even the Lightroom application, and I am dependent neither on my Lightroom catalog nor even on the Lightroom application.

So if I decide tomorrow to never use Lightroom again, or if Adobe decides suddenly to discontinue Lightroom, I can continue to access all my images in any application that supports DNGs.

Should I abandon this process, and act more normally?

Tim’s Quick Answer: I recommend changing your workflow to make the most of all Lightroom has to offer while at the same time ensuring that your workflow is not completely dependent on Lightroom. I also don’t think it is necessarily a good idea to delete the original RAW capture files.

More Detail: I assume you are creating JPEG images to provide a “backup” copy of images that includes the adjustments you’ve applied within Lightroom. I don’t think this is necessary, and including this step in your workflow greatly increases the time and storage space required to accommodate those additional image files. I just see this as unnecessary clutter, in other words. If you get to the point that you can’t (or won’t) use Lightroom in your workflow, you could create copies of all existing images with a single export process at that point.

I’m also not entirely comfortable deleting the original RAW capture files. That is part of the reason I have not adopted the Adobe DNG file format as part of my workflow. But if you prefer to convert to DNG files and delete your originals it is reasonably safe to do so as long as you have confirmed that the DNG files are readable and have been backed up securely.

Frankly, if you’re not going to use Lightroom as the foundation of your full workflow for managing your photos, it might make more sense to find some other software you’re more comfortable with. However, I do think it is smart to avoid becoming too dependent on Lightroom.

Fortunately, with Lightroom it is relatively easy to adopt a workflow where you can leverage what Lightroom has to offer without creating a situation where it is very difficult to transition away from Lightroom at a later date. Photographers who adopted Apple Aperture for their image-management workflow, for example, can greatly appreciate the challenge involved in transitioning away from one software tool to another.

I recommend that you define a workflow that revolves around standard metadata fields, and then saving metadata updates to the image files themselves.

For example, instead of using collections in Lightroom as a key foundation of your organizational workflow, you might want to employ keywords. That way the keywords you add can still be available to any other image-management software you might use at a later date.

To save metadata to the image files on the hard drive, you can select all images in your Lightroom catalog and then choose Metadata > Save Metadata to Files from the menu. You can also have metadata updates saved to your files automatically by turning on the “Automatically write changes into XMP” checkbox in the Catalog Settings dialog (found on the Lightroom menu on Macintosh or the Edit menu on Windows).

My overall strategy involves retaining the original capture format from the camera, using a workflow that focuses on updating standard metadata fields (such as star ratings and keywords) rather than Lightroom-specific features (such as pick/reject flags and collections). I save the metadata to the files automatically, and also try to maintain an awareness of the current state of software so I can anticipate any issues that might require me to alter my workflow.

Flipping Part of an Image

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Today’s Question: In Photoshop, is there a way to copy a portion of the image, and then “flip it” (left to right) for pasting elsewhere in the original image?

Tim’s Quick Answer: Yes, indeed. You can simply create a selection of the desired area, create a new layer based on a copy of the selected area, flip horizontally or vertically with the Transform commands, and then use the Move tool to move the new layer into the desired position.

More Detail: It is quite easy to duplicate a portion of a photo and then flip that new layer and move it into a new position. One common use of this capability is a “mirror image” technique, which can be quite interesting. You can see a sample image I created using this technique on my Instagram feed here (be sure to follow me!):

https://www.instagram.com/p/BKSZZ0OA3l3/

The basic process is very straightforward. Start by creating a selection of the area you want to duplicate and flip. In the example image above, that would involve a rectangular selection of one-half of the image. You can then copy the selected pixels to a new layer by choosing Layer > New > Layer Via Copy from the menu (or by pressing Ctrl+J on Windows or Command+J on Macintosh).

To flip this new layer you can simply choose Edit > Transform from the menu, followed by either Flip Horizontal or Flip Vertical based on the direction you wish to flip. With the sample image linked above the Flip Horizontal command was selected.

You can then use the Move tool to move the new layer to a different location within the image. In the case of the “mirror image” technique, for example, I would have selected and duplicated the right half of the image, flipped the layer horizontally, and then moved the new layer to the left half of the image. But of course you could move the new layer to any position you’d like within the image. If for any reason you need to drag the new layer to a position that falls outside the existing image area, you can simply choose Image > Reveal All from the menu to enlarge the canvas so you can see the entire image area.

For readers who subscribe to my Pixology magazine, you can find more details about this technique in the article “Step by Step: Mirror Image”, featured in the August 2016 issue.

End of the Nik Collection?

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Today’s Question: I remember the time that you were very happy with Nik Software, and recommend it with pleasure. I want to sign up for a Photoshop Creative Cloud subscription. Info on the web informs me that difficulties will rise using Photoshop CC and the Nik plug-ins. Can you tell us whether we should be concerned that the Nik Collection will stop working with Photoshop?

Tim’s Quick Answer: I think there is most certainly a reason to be concerned that the Nik Collection will no longer function well in the near future, and to begin looking for alternative solutions if you are currently using any of the tools in the Nik Collection.

More Detail: The Nik Collection is a set of software and plug-ins that were originally released by Nik Software, which was acquired by Google in 2012. Originally the suggestion was that there would not be any future updates with new features, there would be updates to ensure that these software tools continued to function with operating system and host application updates.

However, more recently Google has updated the page for the Nik Collection (https://www.google.com/nikcollection/) to indicate that no future updates of any kind will be released. The existing Nik Collection (which is still available as a free download) will only function properly with Mac OS X through version 10.10, Windows through version 8, and Adobe Photoshop through version CC 2015.

I have run into some minor issues with several of the software tools in the Nik Collection, and suspect those problems will only increase with future updates to Photoshop and the operating systems.

I will be providing more details on recommended replacements for the various tools in the Nik Collection. In the short term I know many photographers are particularly interested in options for creating high dynamic range (HDR) images. I have found that Adobe Lightroom’s built-in feature for HDR assembly works very well, and that Aurora HDR 2017 is also an excellent solution. Keep in mind that Aurora HDR 2017 is currently only available for Macintosh users, but Macphun Software has indicated that a Windows version will be coming soon.

I will provide more recommendations in the future related to replacement recommendations for the Nik Collection.

Catalog on Two Computers

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Today’s Question: I purchased a new laptop for travel and teaching. I want to use the same Lightroom catalog and images on both machines [laptop and desktop]. What do you recommend?

Tim’s Quick Answer: In this type of situation my recommendation would be to keep both your Lightroom catalog and your photos on the same external hard drive. You can then open the catalog from that external hard drive on whichever computer you’re currently using to work with your images.

More Detail: Lightroom does not offer a native solution for effectively working with your full catalog on more than one computer. That includes the inability to store your catalog on a network storage location, preventing you from being able to access the catalog from multiple computers on a network.

Some photographers have employed an online synchronization service such as Dropbox (https://www.dropbox.com) to make a catalog available on more than one computer. While this can most certainly be a workable solution, I do have concerns about the potential for synchronization failure, and of course this type of approach would require that you have access to an Internet connection in order to synchronize the actual files you’re working with.

As a result of the various limitations related to working with a catalog across two computers, I recommend simply keeping the catalog itself on an external hard drive along with the photos being managed by that catalog. You can then connect the external hard drive to whichever computer you want to work with currently. Within Lightroom, you can then open the catalog directly from the external hard drive, so that you’re always working with the actual catalog files (without the need for synchronization), and you always have your photos readily available as well.

The only potentially significant drawback to this approach of storing the Lightroom catalog on an external hard drive is degradation in performance. Most external hard drives are slower than a comparable internal hard drive, and there are also latency issues that can further degrade performance. For some photographers this reduction in performance is reason enough to work with only a single computer for Lightroom. For example, I keep my Lightroom catalog on my laptop, so that I always have access to the catalog whether I’m at home or traveling with my laptop.

Metadata Mismatch Mistake

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Today’s Question: I get a message about metadata confusion in Lightroom when I work on the image in both Lightroom and Photoshop without closing and reopening the image. I don’t know which choice to check, Import Settings from Disk, or Overwrite Settings. Would you please explain these two choices and the benefits of each?

Tim’s Quick Answer: The solution here is actually to never open an image directly from Photoshop or otherwise update the metadata outside of Lightroom. If you ensure that all tasks related to your images are initiated within Lightroom, you won’t experience this data mismatch in the first place. Resolving the issue for images that have already been impacted requires making a decision about which updates to keep versus discard.

More Detail: If you update metadata for an image outside of Lightroom, the result will be a mismatch between the metadata stored with the image and the metadata in your Lightroom catalog. Even opening a RAW capture directly in Photoshop will cause adjustment metadata to be updated. Updates made outside of Lightroom will not be reflected in your Lightroom catalog, causing a mismatch and potential confusion, as well as the risk of lost data.

For example, let’s assume you add a keyword in Lightroom. If you have enabled the option to automatically save metadata out to the actual files on your hard drive (or you have manually saved that metadata) then you can see the updates in other software. So, for example, the new keyword you added would be visible if you browse the image with Adobe Bridge.

However, if you add a keyword with Adobe Bridge, that keyword will not be visible within Lightroom, because Bridge can’t add the keyword to your Lightroom catalog. Lightroom can recognize when the metadata in your catalog doesn’t match the metadata in the image file on your hard drive, and alert you of this mismatch.

To resolve the issue for images that were processed outside of Lightroom, you’ll need to decide which updates to keep and which updates to discard. For example, if you added “Bridge” as a keyword from Adobe Bridge and you added “Lightroom” as a keyword from within Lightroom, you can’t retain both keywords. You’ll need to choose whether to keep the metadata from the file on your hard drive (“Bridge” in this example) or to keep the metadata within Lightroom (“Lightroom” as a keyword in this case). In this example, one of the two keywords will be lost when you choose an option.

If you choose the “Import Settings from Disk” option in the metadata mismatch dialog, then the Lightroom catalog will be updated with all of the metadata contained in the image on your hard drive, overwriting the metadata for that image in the Lightroom catalog. If you choose the “Overwrite Settings” option, the metadata from your Lightroom catalog will be saved to the image file on the hard drive, overwriting the metadata that was there. In either case, of course, the metadata mismatch will no longer exist.

As noted above, the real solution is to avoid this problem in the first place. Once you start using Lightroom to manage your photos, it is critical that you initiate all tasks related to your photos from within Lightroom. This will ensure that your Lightroom catalog always remains up-to-date.

Lightroom to Photoshop Confusion

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Today’s Question: When opening an in image in Lightroom for editing in Photoshop I’ve always had a pop up that asked if I wanted a copy, copy with Lightroom edits, or the original file to export to Photoshop. After an update, it’s gone, no pop up at all, and it exports the original RAW file. How do I get this pop up back so I can export copies to edit in Photoshop?

Tim’s Quick Answer: Actually, Lightroom is still creating a copy of the RAW file. The only change is that you’re not seeing the dialog, but really the dialog isn’t necessary since a copy would always be created, and your original RAW capture would remain untouched. So having the dialog no longer appear is actually a good thing, although perhaps a bit confusing.

More Detail: A relatively recent update to Lightroom caused the dialog in question to no longer appear when you are sending a RAW capture to Photoshop from Lightroom using the Photo > Edit In command from the menu. With other file types (such as JPEG, TIFF, or PSD) the dialog will still appear, since in those cases you could choose whether you want to make a copy or simply open the source file directly.

With a RAW capture, the source image is processed and sent to Photoshop, creating a TIFF or PSD file in the process. You can choose which file type (and the basic settings for that file) on the External Editing tab of the Preferences dialog in Lightroom.

The adjustments you have applied to the RAW capture in Lightroom will automatically be reflected in the derivative image that is created as part of this process.

Photo Migration

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Today’s Question: I have kept my photo collection on my C drive on my laptop, organized by year and month. I have duplicates of the collection on two external hard drives (J and G drives). Now I wish to delete all photos off my C (internal) drive, and work only from the J drive, with backup to the G drive. How do I manage this transition?

Tim’s Quick Answer: Assuming you have already made an exact copy of the photos on your internal hard drive to the external hard drive, with the exact same folder structure, I would recommend connecting the existing catalog to the external hard drive. This will involve fewer risks than trying to create a new catalog or deleting the photos from the internal drive from within Lightroom.

More Detail: It is important to keep in mind that your Lightroom catalog is simply managing information about your photos and referencing the source image files in their storage location. If you copy photos from one location to another outside of Lightroom, it is important to avoid creating a mismatch between the Lightroom catalog and your overall photo storage.

Normally the approach I would recommend in a situation like this would be to start by creating a reliable backup (or two, or more) of the photos on your internal hard drive. Then, within Lightroom, I would move all of the folders from the internal hard drive to the external hard drive you want to use moving forward.

In this case you have already copied photos from the internal hard drive to an external hard drive. As long as the copy is an exact match of the original (such as by using synchronization software), then you can connect the existing references to your photos to the new storage location.

The first step here is to “hide” the photos on the internal hard drive from Lightroom. This can be as simple as renaming the top-level folder for the overall storage structure, so that Lightroom will no longer find the folders and photos where they are expected. You can then right-click on any of the folders that now appear to be missing within Lightroom, and choose the option to reconnect the missing folder. In the dialog that appears you can then select the corresponding folder on the external hard drive. Lightroom should then recursively reconnect all folders on that external hard drive, so there are no longer any missing photos or folders within Lightroom.

In effect, what you’re doing here is redirecting Lightroom to the exact same folder and photo structure on a different drive. In the process you will not lose any information for your photos, since the catalog information is still available and you are simply referencing different copies of your photos.

Once that overall process is complete and you have confirmed that everything is in order in Lightroom, you can make yet another backup of your photos on the external hard drive, and then delete all photo folders on your internal hard drive to free up space. This last step, of course, should be postponed a little while to make sure all of your photos are safely being managed from your external hard drive before removing the photos altogether from your internal drive.

JPEG File Size Variation

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Today’s Question: I’m puzzled by the extreme variation in file sizes after I resize in Photoshop then compress in JPEG format. My regular work involves processing a group of images starting with a RAW capture, and then processing in Lightroom, then exporting to Photoshop as a 16-bit TIFF. I convert to 8-bit, do routine adjustments, save, and then resize to specific pixel dimensions of 1024 x 681. Then I save as a JPEG at a Quality level of 8, which is where the question arises. The size of the final JPEG images ranges from around 200KB to sometimes 4MB. Is there a good explanation for this?

Tim’s Quick Answer: There can actually be a tremendous degree of variation in file size for JPEG images, based on the contents of the photo. In addition, additional variation can be caused by the amount of metadata embedded in the image as well as whether an ICC profile is embedded as part of the image.

More Detail: It is very common to see file size variations for JPEG images that represent about a factor of six or more. In other words, after processing a group of photos to create JPEG images with the same overall settings, if the smallest file size is around 100KB I would not be surprised if one or more images had a file size of around 600KB.

If you have an embedded profile for some images but not others, this would generally create a file size difference of around 200KB. That can obviously create a larger spread. Metadata will, of course, generally not cause a tremendous variation in file size, though that obviously depends on how much additional metadata (such as keywords) you’re adding to the images.

If some of the images are HDR captures, there is certainly a greater potential for variation in file sizes. That is because HDR images often contain more detail that non-HDR images, and greater detail results in a larger file size with a JPEG image.

I would say that a 4MB file size for a JPEG image that has pixel dimensions of 1024×681 pixels is highly unlikely. I would check to see which ICC profile you are embedding (if any), and the size of that profile. If you are consistently converting the images to the sRGB color space then you shouldn’t see this variation. But if a different profile with a larger file size is being used in some cases, that could certainly explain the larger file sizes in some cases.