Category: Ask Tim Grey

Today’s Question: Why is a stitched panorama said to be preferable to a good wide-angle lens?

Tim’s Quick Answer: The two key advantages to a composite panorama compared to a wide-angle capture of the same general scene is higher resolution and less lens distortion.

More Detail: The overall perspective, or relationship between the various objects in a scene, is in large part defined by your distance from the scene. Therefore, if you photograph a scene from a given position, for the most part you will capture the same perspective regardless of the lens used.

In other words, you could either use a telephoto lens to extract a detail from a scene, or you could crop a wide-angle photo to extract the same detail, and the overall perspective will be the same for both images.

Of course, if you’re cropping a wide-angle photo rather than capturing the same scene with a telephoto lens, you’ll end up with fewer pixels in the cropped image. This addresses the first benefit of a composite panorama compared to a wide-angle photo. To over-simplify a bit, if a composite panorama consists of five frames, the resulting image will have somewhere around four times more pixels across compared to a wide-angle capture of the same scene, taking into account some overlap between frames for the composite panorama.

So, I would say that the primary reason to capture a composite panorama rather than a single wide-angle photo would be to produce an image of higher resolution. This enables the final image to be printed at a considerably larger size than the single wide-angle capture would allow.

In addition, wide-angle lenses generally have more distortion than lenses with a longer focal length. That means you can generally get an image that is more accurate with less distortion using a composite panorama technique as opposed to capturing a single frame with a wide-angle lens.

In some cases, a photographer may want to have the unique “distorted” view that can be created by a wide-angle lens. But when you want to avoid distortion and produce a final image that can be printed as large as possible, creating a composite panorama will help you achieve these goals.

Today’s Question: When you’re in a tricky outdoor white balance situation, do you use any special tools to determine white balance or do you just set your camera and try to make adjustments in post processing? I’m often not sure I’ve gotten it right in post.

Tim’s Quick Answer: You could use a custom white balance setting in the camera to ensure you are starting with color that is as close as possible to the actual lighting conditions, evaluating the results in the camera with a comparison to the scene before you.

More Detail: I typically use the “Auto” white balance setting in conjunction with raw capture, since it is then possible to fine-tune the color when processing the raw capture with no penalty in terms of image quality. That’s because the white balance setting is really just a metadata value and does not actually change the raw image data captured by the camera.

However, if you’re trying to ensure the colors are as accurate as possible, the Auto white balance setting is not necessarily the best option, as you would then need to make adjustments to the color in post-processing based on your memory of the scene.

To help ensure you’re getting a photo with the most accurate color at the time of capture, you could set a custom Kelvin value for the white balance on your camera. You could evaluate the setting with the Live View display, comparing it against the scene before you, or you could capture a test photo to compare to the scene. You could still fine-tune the color in post-processing, but you would be starting out with a photo that has more accurate color based on the lighting conditions of the scene you were photographing.

If you were dealing with a situation where you want the colors to be truly accurate, as though the scene were illuminated by perfectly white light without any color cast, you could use a custom white balance setting in the camera that involves capturing a reference image of a neutral object such as a blank sheet of paper or gray card. You could also use a more sophisticated approach such as using an X-Rite ColorChecker Passport (https://bhpho.to/3aXUlVx).

Today’s Question: A while back you answered a question about how to take multiple exposures of a scene, using Photoshop to blend images and produce a final image without the people who were moving around during the time the images were captured. This was new to me, but I have used neutral density filters and a long exposure to get the same result. It seems to me that using multiple images may be easier to set up and don’t require that you have a neutral density filter on hand, but otherwise is there any advantage to either of these methods?

Tim’s Quick Answer: I would say that capturing a series of images is a more dependable way of make sure that people (or other moving elements) do not appear in the final photo. A long exposure includes the risk that some moving objects won’t disappear completely, as well as the risk that the overall image may be blurry due to camera movement during the long exposure.

More Detail: One solution for making a subject moving across a scene magically disappear is to use a long exposure for that capture. Let’s assume, for example, that you photograph a scene with a 30-second exposure and that someone walks through that scene during the exposure. If it only takes the person a few seconds to walk through the scene, there will most likely not be any evidence of that person in the long-exposure photo.

That’s because the person represents such as short duration of the exposure in any area of the photo that they won’t appear in the image. If they were holding a flashlight or wearing highly reflective clothing, then they may of course produce a ghosted appearance in the image. But the idea is that long exposures can cause moving subjects to disappear from a photo.

However, this approach can be tricky. Not only might the person be illuminated enough to appear with a motion blur across the photo, but sometimes a person or object that is moving through the frame doesn’t move fast enough to completely disappear.

In addition, with a long exposure you have the risk of camera movement causing blur, even if you’re using a tripod. For example, there may be vibrations imparted by a passing vehicle, or the wind might be strong enough to move your lens during the exposure.

Therefore, I find the approach of capturing multiple photos of the scene and then blending the images in post-processing (primarily using Photoshop) provides a better solution. And the blending of those photos can be automated rather easily in Photoshop using the technique covered in an earlier Ask Tim Grey eNewsletter, which you can review here:

https://asktimgrey.com/2020/05/22/automatically-remove-people/

Today’s Question: Can you tell me where the “synchronize” button is in Camera Raw in Photoshop? I want to be able to make adjustments based on one image that apply to other similar images.

Tim’s Quick Answer: In Adobe Camera Raw you can synchronize adjustments on multiple images automatically by selecting all of the photos on the filmstrip and then applying adjustments. You can also synchronize the adjustments from one photo to other selected photos by clicking the sync button at the bottom of the toolbar that appears when you hover over an image thumbnail.

More Detail: When you open multiple raw captures in Adobe Photoshop, all of those images will initially be opened in Camera Raw so you can adjust the settings for the raw captures. You can work on one image at a time if you prefer, but it is also possible to synchronize adjustments across multiple images.

If you select all of the images on the filmstrip within Camera Raw (such as by choosing Edit > Select All from the menu), adjustments you apply are automatically synchronized across all of the selected images.

If you want to synchronize adjustments after applying those adjustments to a single image, you can first set the image with the adjustments you want to synchronize as the active image and then select all of the images. Then hover your mouse over the thumbnails, which will cause a small toolbar to appear at the top-right of the thumbnail. The bottom button is a synchronize button.

When you click that synchronize button, a dialog will appear that enables you to select the specific adjustments you want to synchronize to the other selected images. Turn on the checkboxes for those adjustments you want to synchronize or click the Check All button if you want to apply all adjustments. Then click the OK button and the adjustments from the active image will be applied to the other selected images.

Today’s Question: When I review photos and give them star ratings [in Lightroom Classic], I notice that sometimes when I press the number, the photo automatically advances to the next image, and other times it doesn’t. Do you know what I did to make the photo be able to advance and how I can turn it on and off?

Tim’s Quick Answer: The feature you’re referring to is called “Auto Advance”, which normally can be disabled by turning it off from the Photo menu on the menu bar in Lightroom Classic. However, in this case it sounds like one of the keyboard shortcut options is the culprit.

More Detail: Lightroom Classic includes an option to automatically advance to the next image when you apply certain metadata updates to the current image. For example, if you have Auto Advance enabled, pressing a keyboard shortcut to assign a star rating (the numbers 1 through 5, or 0 for no stars) will cause the applicable rating to be assigned to the current image, and the next image will be selected automatically.

Some photographers find this Auto Advance feature convenient, and others prefer to have the feature disabled. You can turn the option on or off by choosing Photo > Auto Advance from the menu.

However, there are a couple of other ways this feature can be enabled, which can lead to having the automatic advance feature apply unexpectedly.

First, you can hold the Shift key on the keyboard to enable Auto Advance even when it is turned off on the menu. So, for example, if you press Shift+1 on the keyboard a one-star rating will be assigned to the current image, and Lightroom Classic will advance to the next image.

Similarly, if you turn on the Caps Lock feature on your keyboard, the Auto Advance feature will apply. So, with Caps Lock on if you press the number 1 on the keyboard, a one-star rating will be applied to the current image and Lightroom Classic will advance to the next image.

So, in this case I suspect the Caps Lock key is turned on. You can turn off Caps Lock (and make sure not to accidently hold the Shift key when using keyboard shortcuts for things like star ratings) to ensure the Auto Advance feature isn’t activated unexpectedly.

Today’s Question: Is there any way to prevent Lightroom Mobile from syncing images from my iPhone’s Camera Roll?

Tim’s Quick Answer: You can turn off the automatic import of photos on the Import page of the Settings within the Lightroom mobile app.

More Detail: The Lightroom mobile app (for iOS and Android devices) includes the option to automatically import the photos you capture using the camera app on your mobile device. This provides a convenient method of adding those photos to your Lightroom Classic catalog, for example. However, it is possible to disable this automatic import if you prefer.

Start by tapping the gear icon that appears at the top-right of the Lightroom mobile app. That will bring up a Settings page, where you can tap Import to access the settings related to importing photos. There you’ll find individual settings for Photos and Videos. Tap to toggle the setting to on or off based on your preference for importing photos and videos automatically.

Today’s Question: I really like the idea of keeping my Lightroom Classic catalog on an external drive so I can use it with both my desktop and laptop computer. What is the suggested workflow for backing up the external drive and would you have your photos on that external drive as well?

Tim’s Quick Answer: You can keep your Lightroom Classic catalog and photos on the same external hard drive to enable working on different computers simply by connecting the hard drive to the computer you want to use. I recommend backing up that drive with software such as GoodSync (http://timgrey.me/greybackup), though I would also use Lightroom Classic to backup the catalog for maintenance purposes.

More Detail: The Lightroom Classic catalog can’t be used across a network, so if you want to be able to work in Lightroom Classic on more than one computer, you’ll need to move the catalog between computers. The easiest way to accomplish this is to simply keep the catalog on an external hard drive that can be moved between computers.

Keep in mind that performance will generally suffer to some extent when keeping your Lightroom Classic catalog on an external rather than internal hard drive. Therefore, if you are going to keep your catalog on an external hard drive you’ll want to choose a drive with high performance, such as an SSD drive.

You can also keep your photos on the same external hard drive so that both the catalog and photos being managed by that catalog are on the same drive. This makes it easy to switch between computers and work with your catalog and photos, as long as you have Lightroom Classic installed and activated on the computer you want to work on.

To backup the catalog and photos on an external hard drive I recommend a synchronization approach. I use GoodSync (http://timgrey.me/greybackup) for this purpose, but there are other backup solutions that provide similar features.

However, even if you’re using other software such as GoodSync to backup your catalog, I still recommend using backup feature in Lightroom Classic to backup your catalog. That’s because Lightroom Classic enables you to scan your catalog for errors and optimize the catalog as part of the backup process, which can help alert you to potential problems with your catalog and also help improve overall performance.

Today’s Question: For one of my folders when using the Synchronize Folder command in Lightroom Classic with the “Show import dialog before importing” checkbox turned on, I’m seeing an odd behavior. Lightroom Classic initially indicates that there is one new photo. Yet when I click the Synchronize button there aren’t any photos shown and the Import button is grayed out. I’ve tried this several times with the same result. Do you know why this may be happening?

Tim’s Quick Answer: The most likely explanation here is that there is a photo within the folder that is not currently in your Lightroom Classic catalog, but that it is not being imported because that same photo is duplicated elsewhere on your hard drive and is included in the catalog.

More Detail: The Synchronize Folder command in Lightroom Classic makes it easy to update a folder within the catalog to reflect differences on your hard drive. For example, if you add a new image to the folder through your operating system, that photo would not appear in your Lightroom Classic catalog. You could, however, right-click on the folder in the Folders list on the left panel in the Library module and choose Synchronize Folder from the popup menu to bring the “missing” photo into your catalog.

As noted in today’s question, you can also choose to show the Import dialog as part of this synchronization process, so that you can adjust the settings for the import. This would enable you, for example, to assign a Develop preset and metadata preset to the images being added to the catalog via synchronization.

If the Synchronize Folder dialog indicates that there are images to be synchronized, but the Import dialog does not show the images, that is an indication that you have the “Do Not Import Suspected Duplicates” checkbox turned on, and that the images are indeed duplicated elsewhere in the catalog.

This would also suggest that the New Photos filter option is set at the top center of the Import dialog. That will cause the duplicates that are not being imported because of the fact that they are duplicates to be hidden from view. If you instead selected the All Photos filter option you would see the images that are being excluded because they are duplicates, and those images would be dimmed with the import disabled for them.

If you want to import the photos even though they are duplicates, you could turn off the “Do Not Import Suspected Duplicates” checkbox in the Import dialog. And, of course, you’ll probably want to also search for the duplicates within your catalog and deal with them accordingly.

Today’s Question: You discussed the topic of “demosaicing” and touched based on the Bayer sensor. Can you also discuss the Foveon sensor and its potential advantages on capturing color values?

Tim’s Quick Answer: The Foveon sensor captures full color for each pixel, rather than only red, green, or blue for each pixel as with a Bayer pattern sensor. While there are theoretical advantages to the Foveon sensor, there are also limitations that have prevented the Foveon sensor from having a clear advantage over others.

More Detail: As I imagine most photographers are aware, the typical digital camera includes a sensor with a Bayer pattern array, where for each four pixels on the sensor two are capturing only green light, one is capturing red light, and one is capturing blue light.

Because these sensors only capture one out of the three color values per pixel, software must be used to process the resulting image data into a full-color photo. This process is referred to as “demosaicing”.

The Foveon sensor was first used in a camera (the Sigma SD9) in 2002, and I had the opportunity to test that camera at the time. While I was impressed with the technology and the level of detail in the photos from the Foveon sensor compared to other digital cameras at the time, the technology never caught on with the top digital camera manufacturers. In 2008 Sigma acquired Foveon, and several camera models employing the Foveon sensor were released by Sigma over the years.

While there are theoretical advantages to the Foveon sensor based on capturing full-color information, there are drawbacks as well. For example, because light is being absorbed in separate “layers” in the Foveon sensor, the sensor isn’t capturing as much information as you might assume. That translates into a need for additional amplification, which results in noise. The more recent Foveon-based cameras I’ve been able to test exhibited very poor noise performance.

All things considered, I would say that the benefits of the Foveon sensor are outweighed by the disadvantages, and that in general sensors with a Bayer pattern array provide better image quality compared to the Foveon sensor.

Today’s Question: Could you please address the best ways to do local dodging and burning, in Lightroom Classic vs. Photoshop?

Tim’s Quick Answer: In Lightroom Classic you can dodge and burn using the Adjustment Brush to paint adjustments into specific areas of a photo. In Photoshop I recommend a technique that involves painting with black and white at a reduced opacity on a separate layer set to the Overlay blend mode.

More Detail: Dodging and burning involves lightening and darkening specific areas of an image, often to enhance detail or refine the mood of an image. The concept comes from the wet darkroom, where you could dodge and burn by adjusting how much light reached the photographic paper during exposure with an enlarger.

In Lightroom Classic the Adjustment Brush tool can be used to lighten and darken specific areas of a photo. After selecting the Adjustment Brush from the toolbar below the histogram display on the right panel in the Develop module you can set a slight increase or decrease for the Exposure control. Then paint within the image to apply that lightening or darkening to specific areas of the photo. You can add additional edits to enable lightening in some areas while darkening in others, for example.

In Photoshop I recommend a technique that involves painting on a separate layer. Start by holding the Alt key on Windows or the Option key on Macintosh while clicking on the Create New Layer button (with the plus symbol) at the bottom of the Layers panel. In the New Layer dialog that appears, set the Mode popup to Overlay and turn on the “Fill with Overlay-neutral color” checkbox. Click OK to create the new layer.

Next, choose the Brush tool, and set the colors to their defaults of black and white by pressing the letter “D” on the keyboard. On the Options bar set the brush to a 0% value for Hardness and reduce the Opacity for the brush (not the layer) to about 15%.

You can then paint with black on the new layer to darken areas of the image, and paint with white to lighten. Note that you can press “X” on the keyboard to switch between the foreground and background color, which means switching between black and white in this case.

It is possible to apply effective dodging and burning with either Lightroom Classic or Photoshop. However, my preference is to use Photoshop because I find it a little more streamlined to work on a single layer, painting with black or white to switch between darkening and lightening. With Lightroom Classic it can be a little more complicated since you need to work with more than one edit pin in order to be able to both lighten and darken.