Shortcuts for Auto Advance


Today’s Question: If the Caps Lock is on, Lightroom will auto advance [when you assign an attribute to an image].

Tim’s Quick Answer: This is a follow-up to yesterday’s Ask Tim Grey eNewsletter, which addressed the Auto Advance feature in Lightroom. You can indeed turn on the Caps Lock feature to enable auto advance. In addition, holding the Shift key while using a keyboard shortcut to assign an attribute will cause Lightroom to advance to the next photo.

More Detail: Even after more than fifteen years of addressing questions from photographers, sometimes it surprises me to see which specific issues generate the most (and strongest) response. The Auto Advance feature discussed in yesterday’s email provided one of those surprises, with a large number of replies from readers.

In some respects you can think of the Caps Lock key as being an “inverter” for the Auto Advance feature. The specific result depends on whether the Auto Advance feature is already enabled.

As noted in yesterday’s email, you can enable the Auto Advance feature by choosing Photo > Auto Advance from the menu. Note, by the way, that this feature can only be found on the Photo menu if you are in the Library module.

If you have turned on the Auto Advance feature (in which case there will be a checkmark icon to the left of the Auto Advance item on the Photo menu), then turning on Caps Lock on your keyboard will actually disable Auto Advance temporarily. On the other hand, if you have the Auto Advance feature turned off, then turning on Caps Lock will enable Auto Advance.

With this “invert” option for the Auto Advance feature you can temporarily enable or disable the feature. If you prefer to use Auto Advance most of the time you can enable it, and then turn on Caps Lock if you want to disable it temporarily. Or, if you only use Auto Advance occasionally, you can turn it off on the menu and then turn on Caps Lock when you want to use Auto Advance temporarily.

Similarly, you can also add the Shift key to the keyboard shortcut for the attribute you want to assign to an image to invert the current setting for Auto Advance. So, with the Auto Advance feature turned off you can press Shift+1 to assign a one-star rating and advance to the next image. The same Shift key feature works with star ratings, pick and reject flags, and color labels.

Image Auto Advance


Today’s Question: Somewhere I’ve learned to configure Lightroom is such a way that while rating/flagging Photo’s in Lightroom the next Photo in the filmstrip is selected after the present Photo was rated or flagged. After a forced reinstall of Windows and Lightroom, this setting was gone and I don’t know how to get it back. Can you please help me to configure Lightroom again in this way?

Tim’s Quick Answer: You can re-enable the auto-advance feature in Lightroom by choosing Photo > Auto Advance from the menu.

More Detail: When the auto-advance feature is enabled in Lightroom, assigning a rating attribute to a photo will cause the next photo to be selected automatically. This feature works with the pick and reject flags, as well as star ratings and color labels.

So, for example, while reviewing photos if you press the “1” key on the keyboard to assign a one-star rating, the next image will be selected. You could then assign a star rating to that image, including the option of pressing the “0” key to assign zero stars (essentially no star rating) and automatically move on to the next image.

If the auto-advance feature is disabled, then you can instead use the arrow keys on the keyboard to move to the next image.

My personal preference is to keep the auto-advance feature disabled, so that I am always making an explicit decision about when I want to move on to the next photo. But it can obviously also be helpful to have Lightroom automatically advance to the next image whenever you assign an attribute as part of your review process.

Disabling Tool Tips


Today’s Question: Perhaps this is petty, but is there a way to turn off the little text popups that appear in Photoshop when I hover my mouse over the various controls and buttons? I find them to be quite distracting.

Tim’s Quick Answer: You can disable these “Tool Tips” text banners by turning off the “Show Tool Tips” checkbox on the Tools tab of the Preferences dialog.

More Detail: I too find the tool tips text banners to be a bit annoying, though admittedly they can be quite helpful when you’re first getting to know Photoshop. I recommend that new users keep this feature turned on (or turn it on if they have it turned off) to help them get more familiar with the many features within Photoshop. But once you know your way around, it is time to disable this distraction in my view.

This option can be found on the Tools tab of the Preferences dialog. To get to the Preferences dialog go to the Edit menu on Windows or the Photoshop menu on Macintosh, and then choose Preferences followed by Tools.

This will bring up the Preferences dialog with the Tools tab active. You can then turn off (or on if you prefer) the Show Tool Tips checkbox in the Options section at the top of the Tools tab in the Preferences dialog. Then click the OK button to apply the change and close the Preferences dialog.

Smart Preview Size


Today’s Question: How much extra disk space in my catalog do smart previews consume?

Tim’s Quick Answer: Smart Previews in Lightroom consume a surprisingly small amount of storage space. As a general rule you can expect Smart Previews to consume somewhere around 1MB per image, with your specific results depending on the nature of the images being processed.

More Detail: A Smart Preview is essentially an Adobe DNG file resized to no more than 2,540 pixels on the long side. Because there is lossless compression applied, the file sizes are quite small. In my testing I have found that the Smart Preview file size represents approximately 1MB per image. This total can vary considerably based on the types of image files you’re working with, and the effectiveness of compression based on the contents of the photos.

But I think the 1MB per image value represents a good general estimate. That, in turn, translates into about 1GB of storage space for every 1,000 images. For a catalog with 100,000 images, you could expect the data file for your Smart Previews to be about 100GB.

Again, these are just rough estimates, and the actual result can vary significantly based on the types of source images you’re using along with other factors. But the point is that compared to the storage requirements for the original captures, Smart Previews are quite small and manageable.

Missing Feature


Today’s Question: You said: “On the Performance tab you can then turn on the ‘Use Smart Previews instead of Originals for image editing’ checkbox.” I do not see this check box when doing the above. What should I be doing? I generate smart previews when importing new images.

Tim’s Quick Answer: The Lightroom feature that enables you to leverage Smart Previews (rather than the source images) to speed up your workflow in the Develop module was added with version 2015.7 of Lightroom. Updating to the latest version will therefore make this feature available to you.

More Detail: One of the “workflow” changes introduced when Adobe introduced the Creative Cloud version of most of their software applications is the more frequent updates that are available. I have found that many photographers haven’t developed the habit of keeping their Creative Cloud applications up to date.

It is worth noting that a variety of small but helpful features have been released with various updates, and so it is easy to miss some important features in the context of what seems to be a “small” update.

I certainly recommend in most cases that you not update immediately when a new version becomes available. At times a new update may break an existing feature or cause other problems that can impact your workflow. It is therefore a good idea to wait at least a few days, and perhaps check to see if you can find any reports of problems related to the new update. But by updating within a reasonable time you’ll ensure you have access to all of the latest features and updates that are now provided on a more frequent basis as part of the Adobe Creative Cloud subscription model.

Faster with Smart Previews


Today’s Question: You said [in yesterday’s Ask Tim Grey eNewsletter] that you could improve performance by preferring the use of Smart Previews in Lightroom. What does that mean and how do you enable it?

Tim’s Quick Answer: You can improve (often significantly) the performance of Lightroom when optimizing photos in the Develop module by using Smart Previews (rather then the source images) as the basis of those adjustments. To enable this option turn on the “Use Smart Previews instead of Originals for image editing” checkbox on the Performance tab of the Preferences dialog in Lightroom.

More Detail: The Develop module in Lightroom makes use of the original image file as the basis of the adjustments you apply. That helps ensure you see the most accurate previews possible, but can also result in degraded performance. It is possible, however, to use Smart Previews as the basis of your adjustments in the Develop module, which will generally improve performance (sometimes quite significantly).

The first step is to generate Smart Previews for all images you want to work with in this way. You could, for example, select all images in your entire Lightroom catalog and then choose Library > Previews > Build Smart Previews from the menu to generate Smart Previews for those images. You can also build Smart Previews as part of the import process by turning on the “Build Smart Previews” checkbox in the Import dialog.

With Smart Previews built for your images, you could simply make the source images unavailable to automatically make use of the Smart Previews. For example, if the source images are on an external hard drive you could disconnect that hard drive from the computer. Lightroom will then use the Smart Previews in the place of the source images when you work in the Develop module.

In addition, you can prioritize the use of Smart Previews in the Develop module even when the source image files are available, in order to improve performance. You can enable this option in the Preferences dialog, which you can bring up by choosing Preferences from the Lightroom menu on the Macintosh version or from the Edit menu on the Windows version. On the Performance tab you can then turn on the “Use Smart Previews instead of Originals for image editing” checkbox. Lightroom will then use the Smart Preview (if available) within the Develop module, even if the source image is currently available. Note that the preview may not be as accurate, but performance will be improved.

Smart Preview Sync


Today’s Question: Regarding working with Lightroom on two computers and one external hard drive, can’t you work on the smart previews on either device while not connected to the drive and then sync them when connecting?

Tim’s Quick Answer: Not really. With this type of workflow you would still run into problems with the synchronization of the overall Lightroom workflow.

More Detail: Let’s assume you are working with a Lightroom catalog on your computer’s internal hard drive, with your photos stored on an external hard drive. Even if the external hard drive is disconnected, the standard previews generated by Lightroom would enable you to review your photos, and even update metadata in the Library module. However, in this situation you would not be able to work with your photos in the Develop module until you reconnected the external hard drive.

If you generate smart previews for your photos, however, then you would be able to work in the Develop module even when the external hard drive containing the source images is disconnected. You could even export copies of your photos based on the smart previews. When you reconnect the external hard drive the updates will be synchronized based on the source photos.

However, working with two computers would still be problematic.

Today’s question was in response to a question addressed in a previous edition of the Ask Tim Grey eNewsletter. That question related to the approach of storing your Lightroom catalog on an external hard drive with the source image files, so that you could switch between two computers by simply moving the external hard drive between those two computers.

However, this approach does not enable you to work with smart previews on both computers interchangeably. The smart previews are connected to the actual catalog files, and so you would only have access to the smart previews if you had access to the catalog. In other words, you would need to have the external hard drive connected to the computer in order to access the catalog, which in turn means the external hard drive needs to be connected in order to access the smart previews. However, in this scenario the source images would also be available, so you would not derive a significant benefit from the smart previews (other than a potential performance benefit based on prioritizing the use of the smart previews).

Lightroom does not inherently support working with the same catalog across multiple computers. You can move a catalog between computers (such as by keeping the catalog on an external hard drive) to work around this. It is also possible to use an online synchronization service such as DropBox ( to enable a workflow across two or more computers. However, there are also some inherent risks with this approach, so it is not something I would generally recommend.

RAW Support


Today’s Question: Can I update Photoshop CS6 to support new RAW capture formats, such as for the new camera I just bought? I would rather not subscribe to “CC” if I can avoid it.

Tim’s Quick Answer: Adobe is no longer adding support for new RAW capture formats in Adobe Camera Raw for Photoshop CS6. You will either need to subscribe to the Creative Cloud version of Photoshop, or use the Adobe DNG Converter to convert your RAW captures to the Adobe DNG format.

More Detail: When Adobe releases a new major update to Photoshop, updates to older versions of Photoshop (if they are available at all) are generally limited to bug fixes. Support for the latest RAW capture formats is generally limited to the current release of Photoshop (and by extension Adobe Camera Raw) or Lightroom.

Therefore, to be able to process the latest RAW capture formats supported by Adobe Camera Raw (or Lightroom) you need to be using the latest major version of the software. In the context of Photoshop, that means you need to have at least a Creative Cloud Photography Plan subscription so you will have access to the latest updates to Photoshop.

One workaround that works in most cases is to convert your RAW captures to the Adobe DNG (Digital Negative) format, using the free Adobe DNG Converter. Images converted to the Adobe DNG format are supported by older versions of Adobe Camera Raw, including the version available for Photoshop CS6. Thus, in most cases you can convert RAW capture formats that are not supported in Photoshop CS6 to the Adobe DNG file format, and then process the DNG file with Adobe Camera Raw.

Dithering a Gradient


Today’s Question: What is “dither”, and should I enable this option when creating a gradient in Photoshop?

Tim’s Quick Answer: Dithering in the context of a digital image refers to the introduction of “noise” to help prevent issues such as posterization. In the context of a gradient, dithering involves the blending of various color and tonal values to help maintain the appearance of a smooth transition.

More Detail: When you are working with a 16-bit per channel image, dithering is an unnecessary concept. However, for 8-bit per channel images dithering can certainly become a very real concern in certain contexts. The Gradient tool is a good example of when dithering can be helpful.

A gradient by definition is aimed at producing a smooth transition between one value and another. For example, let’s assume you are attempting to create a gradient that transitions from white to black over a range of 3,000 pixels, or around 10 inches assuming a 300 pixel-per-inch print resolution.

If the image containing this gradient is an 8-bit per channel image, there are only 256 shades of gray available to create a white-to-black gradient. That, in turn, means that each individual tonal value on the gradient will require just about twelve pixels. In other words, there will be a series of bands of individual tonal values defining this gradient, each being 1/25th of an inch in size.

By enabling the Dither option (available as a checkbox on the Options bar for the Gradient tool) you can help to create a smoother appearance for that gradient. Instead of having bands of various shades of gray that are 1/25th of an inch wide, you will have the appearance of a smoother gradation thanks to the dithering.

So, dithering is not necessary for 16-bit per channel images in the context of a normal photographic workflow. However, it can be very helpful to ensure that dithering is enabled for any image being adjusted in the 8-bit per channel mode.

What is PNG?


Today’s Question: We had pictures taken at our 50th and the photographer provided them in PNG file format. What is it and how do I convert to NEF or JPG?

Tim’s Quick Answer: The Portable Network Graphics (PNG) image format is actually a very good image format that I consider to be (in most respects) better than the JPEG image format. You could certainly use a variety of different software tools to create a JPEG image based on the PNG, but you may not need to. And there is no way to convert an image file such as PNG or JPEG to a RAW capture format such as Nikon NEF.

More Detail: The PNG image format supports lossless image compression and 16-bit per channel data, which is a considerable advantage in terms of image quality compared to JPEG image files. Frankly, the only real reason to use JPEG instead of PNG is to obtain a smaller file size through the lossy compression employed by the JPEG image format, which does degrade image quality to some extent.

I’m not really sure why the JPEG image format managed to gain wider adoption than the PNG file format. Part of the issue was a lack of support for the PNG format in various software applications. In fact, Adobe Lightroom didn’t even support the PNG format until version 5.

I would suggest keeping the PNG files as your “original” image format, creating other image file types only as you need them. You can use Lightroom to export a copy of the PNG files as JPEG (or other format) images, or use Photoshop or other software to save a copy of the image in a different format. But in most scenarios that probably won’t be necessary, and the PNG files will provide you with a good source in terms of overall image quality.

You could, of course, contact the photographer to see if they were using RAW capture, and if so ask if it would be possible to obtain the original RAW captures for at least your favorite images. But in many cases a commercial photographer will be reluctant to provide the RAW captures, preferring to provide only processed images to the client.