Ask Tim Grey

Today’s Question: When using extension tubes does the effective lens focal length change? If the effective focal length changes does that mean that the f-stop also changes?

Tim’s Quick Answer: Yes, technically an extension tube increases focal length and therefore changes the effective f-stop. However, the metadata for your photos will not reflect this change.

More Detail: An extension tube provides a simple and inexpensive way of enabling a lens to focus at a closer distance. That, in turn, increases the potential magnification of the lens. Therefore, an extension tube provides a very affordable way to do closeup or macro photography.

An extension tube simply adds space between your camera and lens, with no additional glass to potentially degrade image quality. Because the definition of focal length for a lens is the distance from the lens’ nodal point to the image sensor, using an extension tube increases the effective focal length. And since f-stops are calculated based on the lens focal length, the effective f-stop also changes.

However, the metadata won’t reflect the changes to the effective focal length and lens aperture, because the lens is effectively reporting its focal length without taking the extension tube into account. In fact, some extension tubes don’t include electronic connections between the camera and lens, preventing the camera from fully controlling the lens and eliminating metadata about the lens from being recorded at all.

Today’s Question: I noticed there is a “Focal Length 35mm” field in Lightroom Classic, but it is empty for all my photos. Is there a way to populate this field with the applicable values?

Tim’s Quick Answer: The “Focal Length 35mm” field in Lightroom Classic requires that the camera wrote the information to metadata for the photos, and you can’t edit the value in Lightroom Classic.

More Detail: The “Focal Length 35mm” EXIF metadata field is intended to contain the equivalent lens focal length based on a 35mm (full-frame) sensor. So, for example, if you were using a camera with a full-frame sensor, the “Focal Length 35mm” field would show the exact same value as the “Focal Length” field. If you were using a camera with a 1.5X cropping factor and had used a 100mm lens, the “Focal Length 35mm” field would show the effective focal length of 150mm.

However, not all cameras write this information to metadata. Based only on the photos I have in my own library, I haven’t found a single Canon camera that writes this information to metadata, while Nikon and Sony cameras (at least the models from which I have photos) do write this information. The Apple iPhone also saves this information to metadata. But this is obviously not based on any exhaustive research or photo library. It is just to illustrate that some cameras write this information to metadata and others don’t.

The “Focal Length 35mm” field, like most EXIF metadata, is not editable in Lightroom Classic. There are third-party metadata editing tools that enable you to edit EXIF, and I would assume those tools therefore enable you to edit the “Focal Length 35mm” field. However, this isn’t something I would recommend doing in general, and it is also something that would most likely not be a very efficient process in terms of automating the update for multiple photos.

Today’s Question: Is there no “delete” command in Adobe Bridge? I can’t find the command anywhere, so the only option seems to be pressing the Delete key and clicking the Delete (rather than Reject) button.

Tim’s Quick Answer: There is a Delete command in Adobe Bridge, but it is labeled “Move to Bin”, which is admittedly a bit confusing.

More Detail: Some time ago Adobe changed the “Move to Trash” command in Bridge to “Move to Bin”. My assumption is that this was done so that the same command could be used on Windows and Macintosh. In general, when you delete a file it isn’t immediately deleted, but instead put in the Recycle Bin on Windows or the Trash on Macintosh. I assume “Move to Bin” was intended to be a generic version that would work on both platforms.

However, I found this change to be confusing, and many photographers have posted in online forums that they dislike the change.

So, you can select one or more images in Bridge, and either right-click on a selected image or go to the File menu and then choose “Move to Bin” to delete the selected files. They will then be moved to the Recycle Bin (Windows) or Trash (Macintosh).

You can also use a keyboard shortcut to delete selected images, which is Ctrl+Delete on Windows and Command+Delete on Macintosh.

Note by the way that if you have the PathBar (Window > PathBar) enabled, that toolbar includes a Delete button (trash can icon) to delete selected photos. Amusingly, that button is identified as the Delete button, but functions the same way as the “Move to Bin” command.

Today’s Question: I have a list of external editors that appear in Lightroom Classic when I right click on an image and select Edit In. How can I remove an external editor from that list that I no longer use, or has been replaced by a newer version?

Tim’s Quick Answer: You can remove an external editor from the Edit In list in Lightroom Classic by deleting the applicable preset on the External Editing tab of the Preferences dialog.

More Detail: When you install a plug-in that supports operating as an external editor in Lightroom Classic, that plug-in will appear on the Edit In menu, which can be found on the Photo menu as well as on the popup menu when you right-click on an image.

If you later want to remove a plug-in from the Edit In menu, in some cases uninstalling the plug-in may cause it to be removed automatically. If not, you can manually remove the plug-in from the Preferences dialog.

To get started, choose Preferences from the Edit menu on Windows or the Lightroom Classic menu on Macintosh. Go to the External Editing tab, where you’ll find the Preset popup in the Additional External Editor section. Click that popup and choose the plug-in you want to remove from the Edit In menu. Then click the popup again and choose “Delete preset” from the popup. Note that this option will include the name of the currently selected preset as well. You can then close the Preferences dialog, and the plug-in you removed will no longer appear on the Edit In menu.

Today’s Question: The Super Resolution feature in Camera Raw [and Lightroom] sounds similar to Topaz Gigapixel, and I was wondering which you consider the best result.

Tim’s Quick Answer: In my experience Topaz Gigapixel (https://topazlabs.com/ref/273/) produces better enlargements than the Super Resolution feature in Camera Raw, Lightroom, and Lightroom Classic.

More Detail: While I’ve heard many photographers say they’ve gotten excellent results enlarging photos with the Super Resolution available in several Adobe applications, I’ve not been particularly happy with the results I’ve gotten in my testing. I find that Topaz Gigapixel (https://topazlabs.com/ref/273/) provides superior results for all images I’ve tested with both applications.

In particular, I find that with Super Resolution the enlarged images end up with a bit more noise and other visual artifacts. Gigapixel from Topaz Labs provides enlargements that I find to be smoother and sharper, with greater detail and quality.

In fact, based on the results of my testing, when I need to enlarge an image, I skip the Super Resolution feature and simply enlarge with Photoshop’s “Image Size” command. While I have consistently gotten better results using Gigapixel, I also wouldn’t say that the results are dramatically better than using Photoshop, so I don’t consider Gigapixel to be a critical tool in the photographer’s workflow.

However, my experience using Super Resolution causes me to specifically avoid using it, because at least in my experience it slightly degrades image quality compared to using other methods of enlargement.

Today’s Question: I’ve heard photographers talk about how they use both versions of Lightroom (cloud and Classic) for different aspects of their workflow. Is there any problem involved with using both of the Lightroom applications?

Tim’s Quick Answer: I do not recommend using both Lightroom (the cloud-focused version) and Lightroom Classic. That’s especially true if you’ll use the Local tab in Lightroom, because doing so can lead to metadata mismatch issues.

More Detail: While it is possible to include both Lightroom and Lightroom Classic desktop applications in your workflow, I don’t recommend doing so. Instead, I recommend choosing one version and using that exclusively.

The primary risk of using the cloud-focused version along with Lightroom Classic is the risk of metadata mismatches. This is due to the relatively new addition of a Local tab in Lightroom. If you make changes to local images that are being managed by Lightroom Classic, you will create a metadata mismatch because the updates won’t be reflected in the Lightroom Classic catalog.

If you limit yourself to only using the Cloud tab so you’re only working with images that are stored in the cloud, there isn’t any problem with using both versions of Lightroom. However, if you’re using Lightroom Classic I recommend not using (or even installing) the cloud-focused version of Lightroom. If you need the equivalent of the Lightroom desktop application you can instead use the Lightroom mobile app or access Lightroom through a web browser (https://lightroom.adobe.com).

You can learn more about the differences between Lightroom and Lightroom Classic in the recording of my webinar on “Lightroom, Lightroom Classic, or Bridge?!” on my Tim Grey TV channel on YouTube here:

[https://youtube.com/live/BwpneG4y0nQ]

I’ll also be presenting a webinar on the subject of “Traps to Avoid in Lightroom Classic” starting at 12pm Eastern Time today, which you can tune into here:

[https://youtube.com/live/6c98YeivvwM]

Today’s Question: Is there a way in Lightroom Classic to search for only photos that contain two selected keywords rather than including images that contain one or the other but not both? When I select two keywords on the Metadata tab of the Library Filter bar I’m seeing images with one or both of the keywords, rather than only the images that have both of the selected keywords.

Tim’s Quick Answer: Yes, you can limit your search to only those images that include all chosen keywords either by using the “Contain All” option on the Text tab or by using more than one column on the Metadata tab when using the Library Filter Bar.

More Detail: By default, when you set a filter in Lightroom Classic for more than one keyword, that search is an “or” search rather than an “and” search. In other words, if you select keywords Miami and Florida for a search, you’ll see photos that contain either Miami or Florida. As a result, the search results might include an image with keywords of “Orlando” and “Florida”, even though it doesn’t include “Miami” as a keyword.

In this example, if you wanted to only see images from Miami, Florida, and not images from Orlando, you would want an “and” search. This can be handled in a couple of ways.

First, you can use the Text tab of the Library Filter bar, selecting “Keywords” from the first popup and “Contain All” from the second popup. The type the applicable keywords in the text field to the right of the popups, separating each keyword with a comma.

The other approach would be to use more than one column for keywords on the Metadata tab. You could set the popup on the header for the first column to “Keyword”, and select “Florida” from that column. Then set the second column to “Keyword” as well, and select “Miami” from that column. You would then only be viewing photos that include both Miami and Florida as keywords.

Note that when you’re using the Library Filter bar you are filtering images in the currently selected location, such as a folder or collection. If you want to search across your entire catalog you can choose the “All Photographs” collection in the Catalog section of the left panel in the Library module.

Today’s Question: Is there a way to browse the photos in only two subfolders, not all subfolders within a parent folder in Lightroom Classic? I know I can browse all photos by enabling the “Show Photos in Subfolders” option. But what if I just want to browse some (but not all) the subfolders at the same time?

Tim’s Quick Answer: Yes, you can browse only the contents of specific folders in Lightroom Classic by selecting those folders and making sure the “Show Photos in Subfolders” option is turned off.

More Detail: I find that many photographers don’t realize you can browse the contents of more than one folder in Lightroom Classic by simply selecting the folders you want to browse from the Folders list on the left panel in the Library module. In most cases you would want to make sure the “Show Photos in Subfolders” setting (found on the Library menu) is turned off, unless you also want to see photos in subfolders of the selected folders.

To get started, click on the first folder you want to browse on the Folders list. If you want to select a range of folders, you can hold the Shift key on the keyboard while clicking on the last folder you want to select. This will cause the first folder you clicked, the folder you Shift-clicked, and all folders in between to be selected.

You can also toggle the selection of any folder in the Folders list on or off by holding the Ctrl key on Windows or the Command key on Macintosh while clicking the folder. This enables you to select among any folders without having to select a range of folders.

When you select multiple folders, you’ll be browsing all the photos contained within all selected folders. That, in turn, means that the indication of the number of photos you’re currently browsing (shown toward the left side of the top of the bottom panel) will update based on which folders are currently selected, and whether you have the “Show Photos in Subfolders” option turned on or off.

Note, by the way, that the same selection options are also available for collections in the Collections section of the left panel. You can even mix and match, selecting any combination of folders and collections from each of the sections on the left panel.

Today’s Question: I’ve run into a problem where if I choose the Camera Raw filter in Photoshop, I’m getting a blank white image instead of the actual image I’m working on. Is this a bug or am I doing something wrong?

Tim’s Quick Answer: You are most likely choosing the Camera Raw filter (from the Filter menu) without selecting the image layer you’re trying to adjust, such as by clicking on the thumbnail for the Background image layer on the Layer panel before choosing the Camera Raw Filter command.

More Detail: When you apply a filter in Photoshop, including using the Camera Raw filter to access Camera Raw adjustments for an image that is already open in Photoshop, the filter applies to the currently active layer. That layer can be a normal image layer or a smart object that contains an image.

If the preview in the dialog for the Camera Raw filter shows an all-white image, the most likely reason is that you had an adjustment layer selected on the Layers panel when you chose the Camera Raw filter from the menu. As a result, you would be applying the filter to the layer mask for the adjustment layer, rather than the underlying image. By default, a layer mask is entirely white, but could also contain black or shades of gray if you had a selection active when you added the adjustment layer or otherwise modified the layer mask.

So, simply click the thumbnail for the image layer you want to apply the filter to before choosing the filter from the menu. In most cases that would mean the Background image layer, but it could be a different layer if you’re working with a composite image, for example.

Today’s Question: Do color film photo prints have as many colors as modern digital photos? In other words, assuming no editing afterwards, is there an advantage to scanning with 16-bit color vs 8-bit? And can the same be said for scanning negatives?

Tim’s Quick Answer: Photo prints from film don’t contain as much color as modern digital images. If you have the original transparency (film or slide) I highly recommend scanning that, and I prefer to do so with 16-bit per channel color. For photo prints you can scan at 8-bit per channel unless you’re going to need to do significant editing work.

More Detail: Generally speaking, there isn’t a tremendous advantage to scanning an analog color image in 16-bit per channel mode unless you’ll need to do significant editing, but for slides or negatives I prefer to scan at 16-bit per channel just to help ensure optimal quality and fidelity. For scanning prints I recommend using 8-bit per channel mode unless significant editing is going to be required.

The original film contains significantly more information than the print, so I highly recommend scanning film if it is available, using prints for scanning only when the original film images aren’t available.

It is important to note, however, that for black and white images I always recommend scanning in 16-bit per channel mode, because there are only 256 shades of gray available for 8-bit monochrome images. As a result, it is very easy to see banding in an 8-bit black and white image because there aren’t enough shades of gray to support smooth gradations. This is a particular risk if you need to apply strong adjustments to a black and white image.