Category: Ask Tim Grey

Today’s Question: What is your opinion on the use of Tilt-Shift wide-angle lens to reduce (eliminate) perspective distortion?

Tim’s Quick Answer: I think a tilt-shift lens can be incredibly helpful for correcting (and often eliminating) perspective distortion. The key question is whether it makes sense for an individual photographer to add a tilt-shift lens to their camera bag.

More Detail: A tilt-shift lens enables you to move lens elements relative to each other, which makes it possible to correct for perspective distortion as well as to alter the alignment of the depth of field. While a tilt-shift lens is especially valuable for correcting perspective in architectural photography, there are a wide variety of other situations where such a lens can be helpful.

If you were photographing a building from ground level at a relatively close distance, there will always be a degree of perspective distortion, where the building seems to be leaning away from you. In that situation, I would absolutely recommend using a tilt-shift lens if you had one in your bag.

As a result, the real question to me isn’t whether a tilt-shift lens could be helpful, but whether it might be worthwhile to add a tilt-shift lens to your camera bag.

If you frequently photograph subjects (such as architecture) where your photos would benefit from perspective correction, a tilt-shift lens might absolutely be a worthwhile addition to your collection of gear. But if you only need this type of perspective correction (or to apply other creative possibilities) on a somewhat infrequent basis, it might not be worth spending extra money for a tilt-shift lens (or to carry the extra weight of that lens).

Keep in mind that some of the effects you can achieve with a tilt-shift lens can also be accomplished in processing after the capture, although the quality might not be equivalent. This is why in general I consider a tilt-shift lens to only be a worthwhile investment for photographers who will take advantage of its unique benefits on a somewhat frequent basis.

Today’s Question: I like applying a split toning effect to some of my black and white photos. I generally use the Camera Raw Filter to apply the effect, but that only enables two colors to be chosen. Is it possible to create a similar effect with more than just two colors?

Tim’s Quick Answer: You can create an effect similar to split toning but with multiple colors by using a Gradient Map adjustment layer in Photoshop.

More Detail: The Gradient Map adjustment layer in Photoshop enables you to define a gradient that can then be used to map color values in the gradient based on tonal values in the photo.

The first step is to add a Gradient Map adjustment layer to the image. So, select the top layer on the Layers panel, and then click the Add Adjustment Layer button (the half-black/half-white circle icon) and choose Gradient Map from the popup. On the Properties panel select the black-to-white gradient as a starting point.

Next, click within the gradient shown on the popup in the Properties panel to bring up the Gradient Editor dialog. To add a color as a gradient stop, click directly below the preview gradient. Then select a color for that gradient stop, and drag the stop left or right as needed to refine the gradient.

You can continue adding multiple colors, which will be based on tonal ranges within the image. So, the darkest values will be on the left of the gradient, and the brightest values on the right. Be sure to select a color with the desired tonal value, in addition to the overall hue and saturation.

Once you have finalized the gradient, you may want to save it as a preset for future use. To do so, simply click the “New” button in the Gradient Editor dialog. The preset will then be available to use as the starting point for other images. When you’re finished working on the gradient map, you can click the OK button to close the Gradient Editor dialog, and continue working on your image.

Today’s Question: Is there a way to precisely align my cleanup work in Photoshop? For example, when I need to clean on a horizon line, it is important that my cleanup work be aligned with that horizon.

Tim’s Quick Answer: For precise cleanup work in Photoshop, I recommend turning on the “Show Overlay” checkbox in the Clone Source panel. This will cause the source pixels to appear within your brush cursor, so you can easily align those source pixels in the destination area you are painting the cleanup into.

More Detail: The Clone Source panel in Photoshop includes a variety of options related to the source of pixels being used for cleanup tools where you can select a source manually. That includes the Clone Stamp and Healing Brush tools, for example. When you need to be precise with these tools, I recommend turning on the “Show Overlay” option.

If the Clone Source panel isn’t currently visible, you can choose Window > Clone Source from the menu to bring it up. In addition, the applicable tools include a button on the Options bar that will bring up this panel.

I don’t consider most of the options in the Clone Source panel to be especially helpful in my typical workflow. But the Show Overlay option can be tremendously useful. Admittedly, I do find that having this option enabled can be a bit distracting, so I only turn it on when I actually need it for precision painting with a cleanup tool.

To view the overlay showing source pixels you need to have the Show Overlay checkbox turned on, and you need to have sampled a source area by holding the Alt/Option key on the keyboard while clicking in the area of the image you want to use as the source of pixels for your cleanup work. At this point, your mouse pointer that shows the brush shape will display the source pixels within that shape. This enables you to very precisely align the brush before actually painting into the image.

Today’s Question: I’ve seen lens wipes advertised as preventing lenses from fogging up. Do you have any experience with these to know if they actually work?

Tim’s Quick Answer: No, in my experience the wipes that are promoted as being “anti-fog” do not prevent lenses from getting fogged up. Instead I recommend getting the lens to match the ambient temperature to minimize the risk of fogging.

More Detail: In most cases lens fogging is the result of the lens being cold in a humid environment. In my experience the most typical scenario is coming out of an air-conditioned building into a warm and humid environment. The cold lens (and other gear) causes condensation in conjunction with the humidity in the air.

I generally find that in this type of situation, I’m not really able to plan ahead. For example, if it was possible to leave my camera outdoors safely, that would have ensured the camera was not colder than the ambient air, and thus condensation would be less likely to form.

If you’re able to plan ahead, warming up your camera either by taking it outdoors before you plan to start photographing, or using a hair dryer to warm up your camera gear, can help minimize the risk of fogging.

Otherwise, I will simply wait for my camera gear to warm up, which generally takes about five minutes. In extreme cases it may be necessary to use a lens cloth to wipe excess moisture from the lens elements. But very often simply waiting will resolve the issue.

If anyone knows of lens wipes that actually provide an anti-fog capability, please let me know. All of the wipes I’ve tested were not able to prevent fogging at all.

Today’s Question: The other day I launched Lightroom only to see a message that there was a problem with my catalog and it needed to be checked. When the check was complete, Lightroom indicated that the catalog was damaged and needed to be repaired. Thankfully that was successful, but in the process all of the previews for my images changed to gray rectangles. As I browse folders the previews are being rebuilt, but is there a way to build previews for all images at one time?

Tim’s Quick Answer: You can indeed build previews for all images in your Lightroom catalog. Simply navigate to the All Photographs collection in the Catalog section of the left panel in the Library module, select all images, and then go to the menu and choose Library > Previews > Build Standard-Sized Previews.

More Detail: While I’ve certainly known photographers who have ended up with a Lightroom catalog that was corrupted to the point of not being able to be recovered, in many cases Lightroom will be able to repair whatever problems occurred with the catalog so you can get back to work without losing any information. Of course, this underscores the importance of backing up your Lightroom catalog on a somewhat regular basis.

When a catalog is repaired, I have found that the previews file becomes problematic. Fortunately, it is very easy to generate new previews for all images in your Lightroom catalog.

As noted above, the “All Photographs” collection found in the Catalog section of the left panel in the Library module enables you to view all images in your entire Lightroom catalog. You can then select all of the images by choosing Edit > Select All from the menu.

It is important to note that in order to note that in order for Lightroom to build previews for your photos, the source image files must be available. For example, if your photos are stored on external hard drives, those drives must be connected to the computer in order to build previews.

To build previews for the selected photos, you can then choose the appropriate option from the Library menu. When you navigate to the Library > Previews submenu, you’ll see that you can build Standard previews or full resolution 1:1 previews. Select the option that makes the most sense to you, and Lightroom will get to work.

The process of building previews for an entire catalog can take considerable time. Obviously, the specific time will depend upon how many images are in your catalog. However, you can expect the process to require several hours, and possibly a full day or more. Fortunately, photos that already have previews will be skipped, meaning that Lightroom won’t waste time building previews unnecessarily. That also means you can cancel the task and restart it at a later date if needed.

Today’s Question: Which program gives you a better image when cropping, Lightroom or Photoshop?

Tim’s Quick Answer: In the context of simple cropping, both Lightroom and Photoshop provide comparable (and potentially non-destructive) results. My feeling is that a decision should be made based on workflow considerations and personal preference.

More Detail: The simple act of cropping a photo does not cause any change to the image itself, other than removing (or hiding) pixels from view based on your crop. That said, it is worth noting that if you are resizing as part of the crop, there will be some minor differences in the quality of that resizing from one software application to another. Of course, both Lightroom and Photoshop do an excellent (and comparable) job of resizing photos.

In the context of your source image file, cropping (along with all other adjustments) within Lightroom is non-destructive. What that means is that the original image file is not altered in anyway, as the actual adjustments are essentially metadata updates within Lightroom. Of course, when you actually export the image to create a derivative copy, that copy will reflect the adjustments and the cropping, meaning the pixels you cropped out within Lightroom are not included in the derivative image.

Within Photoshop it is also possible to perform a crop non-destructively. When you select the Crop tool you’ll see a “Delete Cropped Pixels” checkbox on the Options bar. Make sure this checkbox is turned off before applying a crop to a photo, and the crop will not actually remove the pixels outside the crop box. Instead, the canvas size for the image will be adjusted to hide the pixels from view. At any time you could choose Image > Reveal All from the menu to enlarge the canvas to reveal all of the hidden pixels in the image.

Because of the similarities of both Lightroom and Photoshop when it comes to cropping, I would say there isn’t a strong reason to choose one over the other for this purpose.

Personally, I tend to perform most of my photo optimization work in Lightroom, and so if I am cropping for aesthetic purposes I would tend to apply that crop in Lightroom’s Develop module. Most of my printing, on the other hand, is initiated from Photoshop, in part because I prefer to have the extra control over output sharpening that Photoshop provides. If I also want to crop as part of that print process, then I would generally use Photoshop to apply that crop.

The bottom line is that you don’t need to worry about overall image quality issues when it comes to choosing to crop in Lightroom versus Photoshop. Therefore, you can let workflow considerations and personal preference guide your decision.

Today’s Question: I use a keyword to identify photos I have shared online, for example. When looking for new images to share, I want to see only those I haven’t shared before. I know in Lightroom I can search for images that contain a given keyword. But is there a way to filter out the photos that already contain the keyword that indicates a photo has already been shared?

Tim’s Quick Answer: You can indeed filter out images that contain a specific keyword by using the “Doesn’t Contain” option when using a text search based on the Keywords field.

More Detail: Most of the methods for filtering images in Lightroom based on keywords involve viewing images that actually contain a specific keyword (or keywords). For example, you can use the Metadata section of the Library Filter bar to select keywords for the images you want to view.

It is also possible, however, to filter based on the absence of a keyword. This can be done using the Text section of the Library Filter bar, or by creating a Smart Collection that includes similar criteria.

You’ll first want to make sure the Library Filter bar is visible. You can enable it by choosing View > Show Filter Bar from the menu, or by pressing the backslash (\) key on the keyboard. Then choose the Text option on the Library Filter bar to display the text search controls. Set the first popup to “Keywords”, and the second popup to “Doesn’t Contain”. Then type the keyword you want to use for your filter in the textbox to the right of the popups. This will filter the current images (based on the folder or collection you are browsing) so that only images without the keyword you entered will be displayed.

If you then enable the “lock” option at the top-right of the Library Filter bar, you can switch among other folders or collections to view images based on your filter. You could also add other criteria, such as star ratings on the Attributes section of the Library Filter bar, so that you filter your images more effectively. In this way, using the example from the question, you could search for some of your best images from various folders, while only viewing images that do not yet have the keyword that is used to identify images that have been shared.

And, of course, this same concept could be used in a wide variety of other situations, where you want to view images that match certain criteria, but that do not contain one or more keywords you specify.

Today’s Question: With a recent Photoshop update, when my mouse is over a tool on the toolbox I get a large popup with a video in it. Is there a way to disable this popup?

Tim’s Quick Answer: You can disable these animated “tooltips” by turning off the “Use Rich Tooltips” checkbox on the Tools page of the Preferences dialog. You can also turn off the standard tooltips by turning off the “Show Tooltips” checkbox on the same page.

More Detail: Tooltips are intended to provide contextual information within a software application. Within Photoshop, for example, the standard tooltips will indicate the name of a tool when you hover your mouse over the button for that tool, along with an indication of the keyboard shortcut for the tool.

While these tooltips can certainly be helpful when you’re initially learning a software application such as Photoshop, they can also be a bit distracting. With the Photoshop CC 2018 update, Adobe added a “rich tooltips” option, which displays an animation demonstrating the basic use of a tool, along with the name of the tool, the keyboard shortcut, and a brief description.

The rich tooltips are controlled by the “Use Rich Tooltips” checkbox on the Tools page of the Preferences dialog. You can get to that page by going to the menu and choosing Edit > Preferences > Tools in the Windows version of Photoshop, or by choosing Photoshop > Preferences > Tools in the Macintosh version. With the “Use Rich Tooltips” checkbox turned on you will see the “rich” version of tooltips, and with it turned off you will see the standard version.

Of course, if you prefer to turn off tooltips altogether, there is an option for that as well. Simply turn off the “Show Tooltips” checkbox on the Tools page of the Preferences dialog, and you won’t see any tooltips at all within Photoshop (rich or otherwise).

Today’s Question: It takes me longer than 30 days to be finished with my 1:1 previews in Lightroom [Classic CC] so I have to delete them manually. When photos are in a stack within a folder and I delete the 1:1 previews for that folder, are the 1:1 previews of the images in the stacks deleted?

Tim’s Quick Answer: Photos that are in a stack will only be selected (and therefore affected by deleting the 1:1 previews) if the stacks are expanded for the folder before you select the images within the folder. Note, however, that you also have the option to remove 1:1 previews for all photos within a folder, even if you did not select all of those photos initially.

More Detail: Lightroom will generate a 1:1 preview for an image when you zoom in on the image. You can also generate these full-resolution previews during import, or later in your workflow using the command found on the Library > Previews submenu.

By default Lightroom will remove 1:1 previews if you have not accessed them within thirty days. In addition, you can choose to have those previews discarded after one week or one day, or to never discard the 1:1 previews automatically. This setting is found on the File Handling tab of the Catalog Settings dialog in Lightroom.

If you want to retain 1:1 previews longer than thirty days, you can select the “Never” option from the “Automatically Discard 1:1 Previews” popup in the Catalog Settings dialog. You can then choose when you want to discard those previews manually in order to free up hard drive space.

So, when you are finished with your review work for a given folder, you could select all images within the folder that you want to remove the previews for. If you want to remove previews for all images in a folder, you don’t actually need to select all of the photos first. Simply choose Library > Previews > Discard 1:1 Previews from the menu, and in the dialog that appears choose the option to discard previews for all images in the folder rather than only the selected images.

If you want to remove these previews for only certain photos, you do need to select those photos individually first. If some of the photos are in stacks, you do need to select all of the images within the stack, rather than only selecting the stack itself. You can streamline this process by expanding all of the stacks within the current folder. To do so, go to the menu and choose Photo > Stacking > Expand All Stacks. You can then select the specific photos you want to remove the 1:1 previews for, and then select the menu command to actually discard previews for the selected images.

Today’s Question: I need to replace my standard zoom lens, and am trying to decide between the 24-70mm lens versus the 24-105mm lens. My next lens in terms of focal length is a 70-200mm. So, should I choose the 24-70mm to avoid overlap between lenses, or opt for the lens with the greater range even though there is an overlap with the 70-200mm lens?

Tim’s Quick Answer: In this case, all other things being equal, I would opt for the 24-105mm lens rather than the 24-70mm lens. The reason is that I would rather have greater utility with a given lens, in order to reduce the frequency with which I need to switch lenses.

More Detail: There are, of course, more than a few factors to consider when choosing a lens. For purposes of today’s question, I will therefore assume the two lens options are essentially equal in all aspects other than focal length (recognizing that there will generally be at least a weight difference involved when talking about two lenses with different focal length ranges).

For me personally, for most photography trips a lens with a range of around 24-105mm tends to be my most-used lens. As a result, I’m particularly interested in having as much utility with that lens as possible. That means I would tend to favor the 24-105mm lens over a 24-70mm lens, assuming my next lens in terms of focal length is a 70-200mm lens.

In other words, I’d rather have a little bit of overlap between my lenses, to help reduce the number of times I might need to switch lenses.

That said, it is also important to consider other factors. In many cases you may find that a 24-70mm lens provides improved sharpness, and possibly a larger maximum aperture size. In addition, a 24-70mm lens will generally be lighter compared to a 24-105mm lens (though not always, based on a variety of factors).

Ultimately, I encourage you to consider which specifications for a given lens are most important to you. But if two lenses meet your needs somewhat equally other than focal length, I would tend to favor the lens with a greater range, due to the increased utility for that lens.