Category: Ask Tim Grey

Today’s Question: Both Adobe Color Themes and blend modes for the brush tool [in Adobe Photoshop] seem to really only be of use for graphics such as in InDesign or Illustrator. Have you found any use in editing photographs for either one?

Tim’s Quick Answer: I would agree that the Color Themes feature in Adobe Photoshop is really more aimed toward graphic designers rather than photographers. However, blend modes can be helpful for photographers in a variety of situations.

More Detail: The Color Themes feature in Photoshop enables you to select and define groups of colors. For example, you could have a group of colors that go well together, such as complementary colors. This type of feature is mostly helpful when you are using color a bit more directly, such as with graphic design. However, there are certainly ways you could employ Color Themes with a photographic image, such as using a theme as the basis of a Gradient Map adjustment to assign color tints based on tonal values in a photo.

Blend modes are also not something I would consider one of the more important Photoshop features for the typical photographer, but there are a variety of ways blend modes can be helpful for photographic images.

In a broader sense, for example, you could use the Multiply or Screen blend modes to create composite images with a multiple exposure effect. This would involve stacking multiple layers, and then selecting a blend mode for one or more layers using the popup on the Layers panel.

Blend modes can also be helpful in the context of the Brush tool. For example, you could use the Overlay blend mode to apply a dodging and burning effect, painting with black and white at a very low Opacity setting. I recommend performing this task on a separate layer, so that the blend mode would actually be applied to the layer rather than with the brush.

To be sure, these features are not among the most commonly used features for photographic images. But as with so many features in Photoshop, there are a variety of ways you can employ the features for creative effects or a streamlined workflow to achieve a particular look for a photo.

Today’s Question: Can you help clear up my confusion about file sizes? When I download a JPEG image from my iPhone, Lightroom shows it as having a file size of around 7.24MB. (The sizes vary from image to image, from about 2.0MB to 7.5MB.) If I send that JPEG to Photoshop I get a PSD image showing a file size of 69.8MB. This size of 69.8MB seems to be constant, no matter what the size of the original iPhone JPEG file is. If I then export the PSD image as a JPEG file I get a JPEG with a file size ranging from about 6MB to about 13.5MB. What’s happening here? Is there a benefit to getting the larger JPEG files by first producing a PSD?

Tim’s Quick Answer: In this case the primary source of confusion relates to differences in compression being applied to the JPEG images. Compression at different quality levels along with variations in the pixel data in the source image can lead to considerable differences from one JPEG file to the next.

More Detail: There are three key factors that affect file size in this context. The first is the total number of pixels contained in the image, meaning the pixel dimensions or number of megapixels. The second is the bit-depth of the image, with JPEG images only supporting 8-bit per channel mode. The third factor is compression, which is a significant variable for JPEG image file size.

With JPEG compression there is a Quality setting, which effectively controls how strong the compression should be applied. Stronger compression yields smaller file sizes, but also lower image quality. That’s not to say the image at a lower Quality setting will always have an obviously degraded image quality, but there is a difference at the pixel level. In addition, the contents of the image affect compression effectiveness. A very simple image will compress to a smaller file size than a complicated image, all other things being equal.

In this particular example one JPEG is being created by the camera (an iPhone), and the other JPEG is being created based on a derivative PSD image. While the latter JPEG may have a larger file size, there has also been an addition application of compression applied, which will have at least a small adverse effect on the quality of the image. So I would still start from the source JPEG capture, even though the file size is smaller.

Note, by the way, that the PSD file has its own set of factors affecting the file size. For example, the PSD created through Lightroom can have a bit depth of either 8-bits per channel or 16-bit per channel, with the latter causing the base file size to be twice as big. In addition a PSD file can contain layers, saved selections, layer masks, and other elements that can increase total file size. As for compression, Photoshop will use lossless compression with PSD files, which can help produce a file smaller than an uncompressed TIFF image, but still considerably larger than a JPEG image.

File size variations can be confusing, to be sure. Just keep in mind that in general it is best to start with your original source capture when optimizing a photo. When creating a derivative image it is generally best to use a file with no compression (or lossless compression) such as a PSD or TIFF image if quality is of primary concern. For other forms of sharing, a JPEG image will often provide a good solution.

Today’s Question: Isn’t it true that preview files [for Lightroom Classic] need to be on the same drive as the catalog? This brings into play the same issue of available storage space you mentioned regarding an internal SSD drive. Preview files can really eat up a lot of drive space resulting in primary drive filling up. For this reason I have just last week moved my catalog and preview files to an external SSD connected to computer via USB-C. The catalog and previews are now removed from my primary internal drive (SSD). If previews can in fact be in a different location than catalog, would it be preferable to return the catalog to the internal SSD C drive but leave previews on external?

Tim’s Quick Answer: Yes, the preview files for your Lightroom Classic catalog must be stored in the same location as the catalog itself. Therefore, the only way to avoid having your previews consume space on your internal hard drive is to move the Lightroom catalog (and thus the previews) to another drive. Keep in mind, however, that this solution can also cause a degradation in overall performance in Lightroom.

More Detail: There’s no question that the previews file for Lightroom Classic will consume considerably more storage space than the Lightroom catalog. That can have a significant impact on the available space on your internal hard drive, especially if your primary internal hard drive is an SSD drive, which will typically provide less total storage capacity than a conventional hard drive.

Just to provide some context, consider my Lightroom Classic catalog, which contains more than 400,000 photos. The actual catalog file that Lightroom uses to manage the information about my photos is less than 4GB in size. The previews file, on the other hand, is almost 90GB in size.

If you want to move your previews file for Lightroom Classic to a different drive, you’ll actually need to move the entire folder that contains the catalog and related files. That can obviously free up considerable space on the internal hard drive on your computer. However, there may be a performance penalty involved with this approach.

Quite often, an external hard drive will offer slower performance than an internal hard drive. The specific performance you can achieve depends on the speed of the storage media itself, as well as the interface used to connect the storage device. In many cases an internal hard drive will have a faster interface than would be available with an external hard drive. So, if you’re going to use an external hard drive to store your Lightroom Classic catalog and related files, it can be critically important to make sure that external hard drive offers optimal performance. Otherwise, relatively slow performance for your Lightroom catalog can result in a frustrating experience within Lightroom.

Today’s Question: I’m trying to figure out a way to import iPhone “Camera Roll” [or other smartphone] photos into Lightroom Classic at full resolution. How can I do this?

Tim’s Quick Answer: You can actually import photos into Lightroom Classic directly from your smartphone through the normal Import feature. You could also download photos using other software, and then import into Lightroom as a separate process.

More Detail: One of the challenges of importing smartphone captures into Lightroom Classic is that Lightroom doesn’t provide a way to delete photos from the source you are downloading from. That means you would need to delete the photos from your smartphone manually after importing into Lightroom, assuming you didn’t want “extra” copies of those photos on your device.

Because of this issue, my preference is to download photos from my smartphone to my computer, using software that includes an option to delete the photos once they are downloaded. I then import those photos into Lightroom separately.

You could use Adobe Bridge to download photos to your hard drive, for example. In the Photo Downloader dialog within Adobe Bridge there is a “Delete Original Files” checkbox. However, if you turn this option on, photos will be deleted from your smartphone as soon as Adobe Bridge finishes downloading them.

My preference is to not delete the photos from my smartphone until I have imported those photos into Lightroom Classic and made an additional backup copy of the photos. Therefore, Adobe Bridge isn’t my preferred solution. I happen to use the Image Capture application included with the Macintosh operating system. With this software I can download the photos from my smartphone, import them into Lightroom Classic, and back up my photos hard drive. I will then delete all of the downloaded photos using the Image Capture software, which I keep running in the background while performing the other tasks.

But again, if you don’t mind manually deleting the photos from your smartphone, you can simply use the import feature in Lightroom Classic to download the source images (including HEIC captures with newer iPhone updates) directly from your smartphone.

Today’s Question: Following up on your discussion of correcting capture time based on different time zones, why don’t you just leave your camera always set to Universal Coordinated Time (UCT)?

Tim’s Quick Answer: While using Universal Coordinated Time (UCT) as a permanent time setting for the camera can be convenient, it can also lead to confusion about what the local time was when a given photo was captured.

More Detail: It can certainly be a minor hassle to need to update the time (and possibly date) on your camera when you travel across time zones. This is one of the reasons many photographers simply leave their camera permanently set to Universal Coordinated Time (UCT). However, this introduces additional challenges if you actually want to know what the correct local time was for the capture of a given photo.

To calculate local time based on UCT, you obviously need to know your location (or at least which time zone you’re in). You also need to know if there are any additional adjustments, such as for Daylight Saving Time in the United States or Summer Time in Europe. These are obviously not insurmountable problems, but they can be especially challenging if you’re trying to locate photos based on capture time long after they were actually captured. If you don’t recall the specific location where a given photo was captured, determining the local time based on the capture time in metadata could be challenging.

My preference is to try to always have the accurate local time reflected as the time of capture in the metadata for my photos. Admittedly, at least with today’s software, that information isn’t always especially helpful. If I’m looking for photos captured around sunset, for example, the accurate timing information can be helpful. But more often than not the capture time is interesting but not critical (and sometimes it isn’t even all that interesting).

While I don’t make extensive use of the actual capture time for my photos all that often, I do prefer to have the information in metadata be as accurate as possible. So I prefer to try to remember to accurately set the time zone for my camera, rather than leaving the camera permanently set to a single time zone such as UCT.

Today’s Question: Do you get better results with HDR (high dynamic range) software or with manual blending such as in Photoshop?

Tim’s Quick Answer: Generally speaking, you will get better results using HDR (high dynamic range) software rather than manually blending exposures. However, in some special cases you may find that you must resort to manual blending of photos.

More Detail: With very few exceptions, you will find that using software specially designed for creating HDR images provides a better overall result compared to manually blending exposures, such as through the use of layer masking in Photoshop.

HDR software accounts for minor differences in framing, such as when the bracketed exposures are captured hand-held. In addition, HDR software can compensate for movement within the frame from one capture to the next, such as when a tree branch is moving in a breeze. As a result, using HDR software will generally provide better results (and much faster results) than could be achieved with manual blending.

The software I prefer for assembling HDR images is Aurora HDR, which you can learn more about by following this link:

https://timgrey.me/hdrtrial

Note that there can certainly be situations were even advanced software such as Aurora HDR is unable to assemble a great HDR image. For example, when photographing the full moon at sunrise I have found that HDR software generally struggles (or fails) with the changes in the moon from one frame to the next.

In the case of the moon, the problem is often twofold. First, depending on the exposure times, there can be enough movement of the moon within the frame to cause problems from one exposure to the next in terms of assembling the final result. Second, at different exposures the halo around the moon may appear with a different intensity and size, which can lead to challenges in combining multiple exposures with HDR software.

In situations where HDR software is not able to create an image you are happy with, you may need to resort to manually blending multiple exposures, such as through the use of layer masks in Photoshop. However, I find that you will generally get the best results using good HDR software, such as Aurora HDR (https://timgrey.me/hdrtrial).

Today’s Question: I keep my images on a separate external hard drive, not on the internal hard drive on my computer. Sometimes I want some of my images available on my computer’s hard drive, so I can for example use an image as my desktop wallpaper. How do I best copy photos from Lightroom [Classic] to a different location on my internal hard drive?

Tim’s Quick Answer: The best way to get photos from your primary storage on an external hard drive to a particular folder on an internal hard drive is to use the Export feature in Lightroom Classic to make a copy of the photo in the desired destination folder.

More Detail: The Export feature in Lightroom Classic enables you to copy photos from the source storage location to another location, with the option to copy the photo as a different file format, along with a variety of other options such as renaming the photo.

In this particular example, you might export a copy of the source photo as a JPEG image, resized to pixel dimensions appropriate to your computer’s monitor display resolution, placing the exported image into a folder in the Pictures folder on your internal hard drive. This, of course, is only one example of how you might take advantage of the Export feature.

After selecting one or more photos you want to export, you can click the Export button at the bottom of the left panel in the Library module to bring up the Export dialog. In the Export dialog you can specify a destination folder, configure settings for renaming the photos, choose the file format and options to use, among other settings.

After configuring the settings for the photos you want to export, you can click the Export button in the Export dialog to create the copies of the selected photos.

Note that there is an “Add to This Catalog” checkbox in the Export dialog, which enables you to create a copy of the selected photos based on the settings you’ve established, and also add the additional copies you’re creating to the Lightroom catalog you’re currently working with. In general I recommend keeping this checkbox turned off.

Generally speaking I find that photographers use the Export command in Lightroom Classic to create additional derivative copies of their photos for a purpose beyond Lightroom. As a result, I recommend avoiding the confusion of having those additional copies of your source photos included in your Lightroom catalog. Instead, I recommend using the exported copies of your photos as appropriate to your needs. When you want to work with the image in Lightroom, return to the original source image (rather than a derivative copy), and proceed from there.

Today’s Question: You recently addressed a question about changing the capture time during import to Lightroom Classic, indicating that you had to wait until after import to change the capture time. Don’t you think it would be better if it was possible to apply this change during import when you know the camera was set to the wrong time?

Tim’s Quick Answer: While in theory it is best to correct capture time as early in your workflow as possible, I actually would not want to apply such a correction during the process of importing photos into Lightroom Classic. That is because I would rather review the photos and make absolutely sure of the time correction required, and that the same correction is needed for all photos.

More Detail: The best time to correct the capture time for your photos, of course, is before you actually capture the photos. In other words, it is best to set your camera to local time as soon as you cross into a new time zone, and before you capture any photos. This would prevent the need to apply a capture time correction after the capture.

Conceptually the next best time to correct capture time would be during the process of downloading the photos from your camera or memory card. However, even if this option was available in Lightroom Classic (which it isn’t), I would prefer to wait until after the photos have been downloaded before applying any correction to the capture time.

The reason for this is that if I’m going to apply a correction to capture time, I want to take the time to double check how much correction is necessary, and which photos actually need the correction. For example, if you changed the time zone on your camera partway through a trip, you would only want to correct the photos that were captured before you changed the time on your camera.

When I realize I have neglected to correct the time zone on my camera during travels, I typically wait until after I’ve downloaded the current batch of photos to correct the time on my camera. That will help avoid confusion in terms of which photos need a correction and which do not.

In addition, before applying a correction I prefer to review my photos to double-check the adjustment that is required. I’ll often, for example, check the capture time in metadata for a photo that was captured around sunrise or sunset. By confirming the actual time of sunrise or sunset, this review enables me to easily confirm the number of hours required for the time zone correction.

Because I prefer to review the metadata for my photos before applying a time zone correction, I would tend not to apply a time zone correction during import into Lightroom Classic even if that feature were available, saving that work for right after the photos have been imported and I’ve had a chance to review the metadata for those photos.

Today’s Question: Do you use Smart Previews (or not) in Lightroom [Classic]?

Tim’s Quick Answer: Generally speaking, I do not use Smart Previews in my Lightroom Classic workflow. I generally rely on Standard (or 1:1) previews for my general image review, and the original source image files for processing my photos.

More Detail: Smart Previews in Lightroom Classic provide some potential workflow advantages, but personally I’ve not generally found those advantages to be particularly compelling.

There are two core advantages to building Smart Previews for your photos. First, Smart Previews enable you to work with your photos, including in the Develop module, even when the source photos aren’t available. For example, if an external hard drive that contains your photos is not connected to your computer, you could still work with those photos in the Develop module if you had built Smart Previews.

In addition, Lightroom Classic includes an option (in Preferences) to favor the use of Smart Previews in the Develop module in order to speed up overall performance when optimizing your photos.

Generally speaking, I have my hard drives available when I am working in Lightroom Classic, and so I simply connect the applicable hard drive when I’m working in Lightroom. Part of the reason I prefer this approach is that I am often combining tasks such as importing new photos while reviewing existing photos, causing me to need to have my hard drive connected in any event.

I’ve also not found that the use of Smart Previews provides a significant performance advantage when working in the Develop module. Part of the reason I’ve not seen a significant benefit in this regard is that I don’t actually tend to spend very much time working with my photos in the Develop module.

To be sure, there are advantages provided by the use of Smart Previews, and many photographers may want to build Smart Previews and enable the option to prefer their use for the Develop module. I simply have not found a benefit in my own workflow that makes me feel the extra storage space required by Smart Previews would be worth consuming to achieve what I consider to be modest benefits in my workflow.

Today’s Question: Do you do ALL of your keywording up front as you are importing photos, or do you do high-level keywording first and then go back and add more detailed keywords after the fact?

Tim’s Quick Answer: I only apply very general keywords during import into Lightroom Classic, and then apply more detailed keywords later in my workflow. This is in large part because Lightroom (like many other software tools) only allows you to define keywords during import that will apply equally to all photos being imported.

More Detail: In some respects the ability to assign keywords during import into Lightroom Classic (or other software) doesn’t provide much utility. After all, because you can only define a single set of keywords that can be applied to all of the photos being imported, you can’t get very specific with your keywording at that stage of your workflow.

For example, let’s assume you have took a photo trip to Italy that includes visits to Rome and Naples. You could apply the keyword “Italy” to all of the photos upon import, since all photos being imported would have been captured in Italy. However, you could not apply “Rome” or “Naples” as keywords, because some of the photos will have been captured in Rome (not Naples) and others would have been captured in Naples (not Rome).

I still apply some basic keywords during the import process, but it is important to be careful at this stage of your workflow to only apply keywords that apply equally to all photos. That means these keywords will be relatively “generic”, which in turn means these won’t be the most useful keywords in your workflow. However, since it only takes a few seconds to enter some basic keywords for the photos you are importing, I still feel this is a worthwhile task.

Later in my workflow I will then add more detailed keywords to my photos. My typical approach is to only assign keywords to my “favorite” photos (those to which I’ve assigned a star rating). I don’t personally go into extensive detail assigning keywords, simply focusing on keywords that will help remind me of the subject appearing in a photo, as well as helping to ensure I’ll be able to find particular photos later.