Ask Tim Grey

Today’s Question: [Following up on a question about the target color value for monitor calibration in the November 3rd edition of the Ask Tim Grey eNewsletter,] isn’t a higher Kelvin number warmer (more red) versus a lower number cooler (more blue)?

Tim’s Quick Answer: Actually, a lower Kelvin value does indeed relate to what we think of as a “warmer” color (more red), and a higher Kelvin value relates to what we think of as a “cooler” color (more blue).

More Detail: Our psychology of color is essentially reversed relative to the Kelvin scale. At the lower end of the Kelvin scale are “warm” colors such as red, orange, and yellow. At the higher end of the scale are “cool” colors such as blue.

The Kelvin scale is based on a theoretical black body radiator. In other words, when you heat something up, the color of light emitted as it glows with heat relates to a value on the Kelvin scale.

As you heat up an object, it will glow first with a “warm” color, such as orange. As it gets hotter and hotter, it will eventually glow with a “cool” blue light, until becoming “white hot”.

So, the Kelvin scale goes from “warm” colors to “cool” colors based on our psychology of color, but those color values actually relate to the color temperature of light given off by an object as it is heated.

Adding further confusion, the Temperature scale also seems “backwards”. You drag the slider to the right for a higher Kelvin value, but that also results in a warmer appearance in the image. But this is because this slider value relates to the color temperature you want to compensate for. So a high value represents a “cool” color, and the software compensates for that cool light by warming up the image.

Today’s Question: If I upgrade to Photoshop CC from CS6, will I be able to maintain a RAW image instead of having to convert to DNG? I would like to stay with RAW and not maintain DNG files.

Tim’s Quick Answer: Yes, if you upgrade to Photoshop CC via a Creative Cloud subscription, you will be able to process your RAW captures without the need to convert to the Adobe DNG file format first.

More Detail: One of the ways Adobe encourages photographers to upgrade to the latest version of Photoshop is to provide updates to the latest proprietary RAW capture formats only in the latest major version updates of Photoshop. So, for example, if you are using an older “CS” version of Photoshop you won’t be able to get updates to Adobe Camera Raw to support the latest RAW file format updates in the newest digital cameras.

One workaround for this issue is the free Adobe DNG Converter. The Adobe DNG (Digital Negative) file format is an openly documented file format that can be used in place of a proprietary RAW capture. In fact, many cameras now support DNG as an alternative (or exclusive) form of RAW capture.

So, with an older version of Photoshop that doesn’t support a newer RAW capture format, you could simply convert those files to the Adobe DNG format with the free Adobe DNG Converter, and then open those DNG files in your older version of Photoshop.

One of the advantages of upgrading to the latest version of Photoshop is that newer proprietary RAW capture formats will still be supported, without the need to convert to the Adobe DNG file format first. And, of course, you’ll gain access to a large number of new features that have also been added to Photoshop since the transition to the Creative Cloud model. In some cases those new updates are rather impressive, so there is more to gain than simple support for the latest RAW capture formats.

Today’s Question: I created a workspace in Photoshop based on your recommendations long ago. The problem is that I sometimes move panels around for various reasons, essentially breaking my saved workspace. When I then try to choose my workspace it doesn’t go back to the saved version. How can I get back to my workspace just the way I saved it?

Tim’s Quick Answer: To reset your current workspace to the saved version, simply choose Window > Workspace > Reset [Workspace Name] from the menu. This will reset the current Photoshop workspace to the saved version of the selected workspace.

More Detail: I find that many photographers leave Photoshop configured with the default workspace. That means that panels you don’t really need are visible within the interface, and that panels you could benefit from aren’t readily available. For this reason, I highly recommend creating your own custom workspace.

Start by hiding panels you don’t want and revealing any “missing” panels that you do want. You can choose among the many available panels from the list on the Window menu. Then arrange the panels in the desired layout by dragging panels around, grouping panels together, and more.

When you’ve configured the Photoshop interface just the way you want it, go to the Window menu and choose Workspace followed by New Workspace. In the New Workspace dialog enter a meaningful name so you’ll be able to choose your workspace from a list. For example, I just use my own name as the name of my saved workspace. But you could also name different workspaces based on the tasks you use each workspace for. Click Save to save your workspace.

You can then choose your workspace from the submenu displayed by choosing Window > Workspace from the menu. And as noted above, if you make a bit of a mess of your workspace after activating it, you can reset it by going to the Window menu, choosing Workspace, and then selecting the “Reset” command that will include the name of the current workspace as part of the menu item. This will reset the current workspace to the version you saved.

Today’s Question: Recently I read an article by a photographer in which he suggested using 6000K [Kelvin] as the target color temperature for monitor calibration, since he felt that temperature produced the most accurate image reproduction. As for me, I’ve never come across that before.

Tim’s Quick Answer: I would actually (mostly) agree with the recommendation to use a slightly “cool” color temperature target for a monitor display. Even though the “standard” illuminant for a print is a slightly “warm” 5000K, I recommend 6500K as an appropriate color temperature target for your monitor display.

More Detail: When it comes to a color-managed workflow for photography, the key is to ensure consistent and predictable results. That includes making sure that you are viewing an accurate image on your monitor display, and that you are producing prints that are an accurate reflection of the image file you are printing.

The “standard” illuminant for evaluating prints is a 5000K light source. This is a relatively neutral (though arguably slightly warm) light source used as the basis for printer profiling, for example. Naturally you won’t always display prints using a 5000K light source, but color management standards generally revolve around this illumination color temperature.

It might seem reasonable to assume that if you will evaluate prints based on a 5000K light source you should also calibrate your monitor display to a color temperature of 5000K. However, doing so will produce a very yellow and dingy appearance on your monitor display.

Instead, I recommend calibrating your monitor display to a color temperature that is closer to the native white point of that display. I recommend 6500K as that target value. The result will be slightly shifted toward blue, especially compared to a 5000K illumination source. But the result will be a more accurate rendition of your image on the monitor display.

Keep in mind that there is always a degree of interpretation involved when comparing an image on a monitor display compared to a print. This is in large part due to the dramatic difference between emitted light (with a monitor display) and reflected light (with a print). This is part of the reason that the calibration target values are different for monitors versus prints.

Of course, if you’re not calibrating your monitor display, then you can’t expect accurate prints. A great tool for display calibration you might consider is the ColorMunki Display from X-Rite, which you can find here:

http://timgrey.me/munkidisplay

Today’s Question: Is there a way to back up the Lightroom catalog to an external drive from within Lightroom? To me this seems to be a logical choice but if there is a way I cannot find it.

Tim’s Quick Answer: Yes. You can initiate a Lightroom backup at any time by choosing the “When Lightroom next exits” from the “Back up Catalog” popup in the Catalog Settings dialog. And when you initiate the actual backup, you have the option of specifying the location where you want the backup saved.

More Detail: By default Lightroom will prompt you to backup your catalog once each week. If you don’t specify a location where you would like the backup copy saved, the backup will be saved in a folder structure along with the source Lightroom catalog. Hopefully it goes without saying that keeping your backup copy on the same storage device as the original isn’t the best idea. So you’ll want to refine the default settings.

First, as noted above, you can initiate a backup of your Lightroom catalog at any time. Start by choosing Catalog Settings from the Lightroom menu on the Macintosh version or from the Edit menu on the Windows version. In the Catalog Settings dialog go to the General tab and click the “Back up Catalog” popup. Choose the “When Lightroom next exits” option, then close the Catalog Settings dialog and quit Lightroom.

At this point you will be prompted to backup your Lightroom catalog. The “Backup Folder” label indicates the destination where the backup copy will be saved. You can click the “Choose” button to bring up a dialog where you can specify the location to save the backup copy. I always recommend saving this backup on a drive other than the drive where your Lightroom catalog is actually stored.

I recommend always leaving the two checkboxes in the Back Up Catalog dialog turned on. The first is “Test integrity before backing up”, which as the name suggests will cause Lightroom to check that there aren’t structural problems with your catalog file before the backup. The second checkbox is “Optimize catalog after backing up”, which will clean up the catalog to help improve overall performance in Lightroom.

The “When Lightroom next exits” option in the Catalog Settings dialog is actually a temporary setting. When you select this option and quit Lightroom, you will be prompted to backup the catalog. However, the next time you launch Lightroom you will find that the setting has reverted back to whatever it had been set to previously. So, for example, if you have Lightroom set to backup your catalog weekly but then you use the option to backup the next time you quit Lightroom, the setting will actually return to a weekly backup schedule after that.

Today’s Question: When taking a RAW file through post-processing, creating a master file (a TIFF or PSD), and then creating a derivative file from the master file for social media, etc., is it possible to trace the derivative file back to the original RAW file and/or master file? I ask because in organizing my Lightroom catalog, I came across a JPEG that looks like it was processed from one of my RAW files, but has no information in the EXIF data identifying where it originated from. My file renaming over the years has screwed-up any naming associations I could possibly make to help with identifying this JPEG’s origins, so no help there.

Tim’s Quick Answer: For an existing image, you can generally use metadata values (such as capture time) to help you locate the original photo that was used as the basis of a derivative image. In this case it sounds like that isn’t an option because the exported JPEG had some (or most) of the metadata excluded. That certainly makes it difficult to match up a derivative image with the source image. Moving forward you might consider retaining metadata in exported images, and grouping derivative images into a stack with the original source image.

More Detail: By default, when you send a photo from Lightroom to another application (such as Photoshop) the derivative image will have the same base filename as the source image, and will be saved in the same folder. This generally makes the task of locating the source image for a given derivative relatively easy.

If the derivative was moved to a different location and you have renamed that file so that it no longer matches the source image, the search for the source image can be a little more complicated.

As long as the metadata from the original image is included with the derivative image, that metadata can often be used to locate the original photo. For example, you could navigate to the “All Photographs” collection in the Catalog section of the left panel in the Library module, and then filter images based on the capture date of the derivative image. Sorting by capture time would then reveal the source and derivative images right next to each other.

In a similar way, you could use any other metadata that was somewhat unique to the image in question as the basis of a filter to help you locate the original. But if the metadata from the original image is not included in the derivative image, the use of metadata obviously won’t be helpful in your search.

Another option relates to stacking images together. By default, when you send a photo to Photoshop from Lightroom, the derivative image will be placed into a stack with the original. You can turn this option off in Preferences, but I recommend leaving it turned on so that you will have the original and the derivative grouped together in your Lightroom catalog. In addition, I prefer to retain the same base filename, and keep all derivatives in the same folder as the source image.

Today’s Question: Is there any advantage to using Adobe Camera Raw in Photoshop to process JPEG images? I just learned that this is possible with JPEG and TIFF images, but I’m not sure if this is something I should add to my workflow.

Tim’s Quick Answer: There is no advantage in terms of general image quality related to using Adobe Camera Raw versus other adjustment options (such as within Photoshop). However, there are some features of Adobe Camera Raw that provide better results than other tools, and some photographers simply find Adobe Camera Raw easier to use.

More Detail: As the name suggests, Adobe Camera Raw is primarily focused on processing RAW captures. This relates to the fact that most RAW captures don’t contain full pixel values, since the individual pixels on an imaging sensor don’t capture all of the information required for the final photo. RAW processing software calculates the full pixel values based on the data actually captured by the image sensor in the camera.

While performing this task, of course, it makes sense to apply adjustments to optimize the overall appearance of the photo. In some cases the application of those adjustments during the RAW processing step of the workflow can improve overall image quality. Other adjustments in RAW processing software are applied after the RAW capture has been converted to actual pixel values, and thus don’t provide a benefit in the context of RAW processing versus general image adjustments.

However, Adobe Camera Raw does provide excellent results for some of the adjustments, and in some cases a workflow advantage as well. For example, I have found that the noise reduction in Adobe Camera Raw (and by extension the Lightroom Develop module) is excellent, and so I prefer to employ this software for reducing noise in my photos.

Other adjustments, such as the “Guided” Upright feature in the Transform tool, provide a workflow advantage, making it easier to apply certain adjustments. With this type of example you aren’t necessarily getting an image quality advantage, but the workflow advantage can be significant in some cases.

In addition to the ability to process JPEG and TIFF images (in addition to RAW captures) with Adobe Camera Raw directly, you can also apply Adobe Camera Raw as a filter to any image using the Filter > Camera Raw Filter option from the menu in Photoshop.

And to learn more about optimizing your RAW captures using Adobe Camera Raw, check out my new video course, “Optimizing with Adobe Camera Raw”, available here:

http://timgrey.me/learnacr

Today’s Question: I deleted [removed] a RAW (CR2) image from the Lightroom catalog by accident. In Lightroom I had converted it to black & white. When I realized that I shouldn’t have removed it, I re-imported it.

The problem is that the image that appears back in the catalog has no history other than “Import” and it appears as a black & white image. I can’t figure out how to get the colored original back. I’d like to rework it from scratch because I’ve learned so much since I did the conversion years ago.

Tim’s Quick Answer: You can get back to the color version of this photo by simply choosing “Color” from the Treatment setting at the top of the Basic section on the right panel in the Develop module.

More Detail: All of the adjustments you apply in the Develop module in Lightroom are non-destructive. What that means is that making changes to the appearance of a photo in Lightroom won’t actually alter the source file on your hard drive.

That means you can make changes to any of the adjustment settings for the image as desired. In this case, for example, that could simply involve changing the Treatment setting from “Black & White” to “Color”.

In addition, note that you can always click the Reset button at the bottom of the right panel in Lightroom if you want to return to the default settings for interpreting the image in Lightroom. This option provides you with the ability to get a “fresh start” for the image in the Develop module.

With regard to the History in the Develop module, when you initially import a photo the only history that will be shown is the actual import step. However, adjustments applied previously can still be reflected. Adjustment settings from the Develop module can be written into the XMP sidecar file for RAW captures, and directly into the file for other supported image file types. You can save most standard metadata information as well as Develop settings for an image by choosing Metadata > Save Metadata to File while in the Library module. You can also enable an option to always automatically save this information by turning on the “Automatically write changes into XMP” checkbox on the Metadata tab of the Catalog Settings dialog.

It is worth noting that if you had exported a derivative image file, such as by creating a JPEG or TIFF image from your original RAW capture, any adjustments in the Develop module would be applied to the actual pixel values in that JPEG or TIFF image. But in the case of a RAW capture, you can always get back to the original interpretation of the image.

Today’s Question: I have an iMac with two displays: an integrated 21″ monitor and a Dell UltraSharp 2401. Originally I set different brightness levels for Internet viewing (Apple monitor) versus printing (Dell). The Dell brightness was therefore set quite low. I now want to recalibrate so that the Dell is for images to be displayed on a digital frame with (hopefully) Adobe RGB color space. For accurate reproduction according to use, where should I set the brightness level for each monitor?

Tim’s Quick Answer: For the display being used to evaluate adjustments for printing I would still recommend using a relatively low brightness value, on the order of around 90 to 120 cd/m2 (candelas per square meter). For the display used to prepare images for a digital display it is reasonable to tend toward a value closer to around 200 cd/m2.

More Detail: There are two issues at play here. First, when evaluating a photo on your monitor display for purposes of preparing that image for print, it can be very helpful to use a relatively low brightness setting. The reason is that the final print doesn’t emit light the way your monitor display does, and so will naturally appear less luminous. By using a darker display you’ll have a preview that is closer to your final print, and thus will be able to make more accurate decisions about the adjustments you apply.

The second issue is that all of the other digital methods of sharing tend to involve non-calibrated displays with a wide variety of brightness settings. Those brightness settings tend to be significantly brighter than what would be recommended when preparing an image for print.

The result is that you can’t ever be completely sure what the final image will look like in a situation where the image will be viewed on a display you don’t have control over. My personal approach in these types of situations is to prepare the images with the display set to the maximum brightness setting.

For something like a digital photo frame, you have the added advantage of being able to evaluate the result. You could, for example, share an all-white image on the digital frame, and then compare that to an all-white image on your computer’s display. If you adjust the brightness on your monitor display (or the digital frame if it is so equipped) then you can then use the monitor display to accurately adjust the overall images so they’ll look good on that digital frame.

It is important to keep in mind that you also want to ensure color accuracy, along with being able to fine-tune the tonality based on your intended use. For that purpose I recommend a product such as the ColorMunki Display from X-Rite, which you can find here:

http://timgrey.me/munkidisplay

And hopefully we’ll one day have a situation where everyone is calibrating their displays, so we can always count on our images being displayed accurately!

Today’s Question: I had a hard drive crash that was referenced in my Lightroom Catalog. I had backups of the files and have restored those files to other drives. However, the hard drive still shows up in the list of drives in Lightroom. How do I remove that drive from Lightroom?

Tim’s Quick Answer: To remove a hard drive from the Folders list on the left panel in the Library module, you simply need to remove all folders (and therefore photos) from that drive within Lightroom. You can accomplish that by selecting all of the photos, right-clicking on one of the folders, and choosing “Remove” from the popup menu. Note that in this specific situation, all of the folders in question would appear as “missing” folders.

More Detail: I am assuming in this case that all of the photos represented as being on the failed hard drive are now represented on the new drive. In other words, it is important to make sure you’ve added back all of the photos from a backup copy before removing the reference to the original photos. I’ll have more to say on this in a moment.

If you’re certain that all of the photos represented on the failed hard drive (and thus showing as missing in your Lightroom catalog) have indeed been replaced with backup copies, you can remove all of the folders from the failed drive very easily.

Start by clicking on the first folder on the list of folders for that drive and then holding the Shift key on the keyboard while clicking on the last folder on the list. Then right-click on any one of the selected folders and choose “Remove” from the popup menu. Confirm your decision in the dialog that appears, and all of the selected folders will be removed. Once all folders and photos from that drive have been removed from the Lightroom catalog, the drive itself will disappear as well.

I should hasten to add that in a situation like this there is an easier way to recover your photos. The easiest approach is to simply replace your original photos drive with a backup drive. If you are using a synchronization approach to backing up your photos (which I highly recommend), this is particularly simple. You can disconnect the failed drive, then update the backup drive to look exactly like the failed drive. In other words, change the drive letter on Windows or the volume label on Macintosh to the same setting used by the original drive. Lightroom will then be able to find all of the photos just as though nothing had changed.

If your backup isn’t quite as organized as would be the case with a synchronization approach, there are still relatively straightforward ways to recover from a drive failure. For example, you could disconnect the original failed drive and connect the backup drive (or otherwise make the backup copies available) and use the “Find Missing Folder” option for the folders that show as missing from the original hard drive, restoring access to your backup photos as part of your existing Lightroom catalog organization.

And, of course, whenever a drive fails I recommend that your first order of business be to create another backup copy of your photos as quickly as possible. If, for example, you have only your master copy of your photos plus a single backup, a failed drive means you no longer have a backup.