Why You Should Not Stack Filters


Today’s Question: I use Hoya Fusion Antistatic UV filters [https://timgrey.me/hoyauv] on my lenses. Should I remove them and screw in my variable neutral density filter when the need arises? Or can I screw the neutral density filter onto the protector filters?

Tim’s Quick Answer: I recommend removing the UV filter from the lens before attaching the neutral density filter, simply to reduce the risk of lens flare caused by having multiple filters stacked together.

More Detail: You can most certainly stack more than one filter together if you have a reason to do so. For example, if an exposure would benefit from using both a graduated neutral density filter along with a solid neutral density filter, you can absolutely stack those two filters together on the lens.

However, there are a couple of reasons to avoid using more than one filter if you can. First of all, whenever you add a filter, you are reducing overall sharpness and detail in the images you capture at least a small amount. This isn’t generally a significant concern with high-quality filters, but it is worth keeping in mind that if a filter isn’t really providing a benefit, it is probably better to not use it.

When stacking more than one filter you are also increasing the risk of lens flare caused by light reflecting back and forth between those filters. This can result in bright spots in the image, just as you might see with lens flare caused by the internal lens elements, when the sun or other bright light source is in front of the lens.

If there isn’t a strong light source in front of the lens this lens flare with the filters won’t be a concern. But I recommend avoiding the stacking of filters in general to avoid this risk, so that you’re in the habit and don’t forget to remove an unnecessary filter when there is a risk of flare.

Direct Deletion from Memory Card


Today’s Question: I have started using Photo Mechanic when I shoot wildlife because it is so much faster than the Lightroom Classic import. A friend told me I should do my sort of the keepers and rejects from the card itself, then erase the rejects directly from the card using my computer. My workflow is to then import the remaining images into Lightroom Classic. I know it is bad to erase images from a card using the trash button on my camera. But is it OK to erase individual images from a card via the computer?

Tim’s Quick Answer: It is perfectly safe to delete photos from a memory card, either on your camera or using your computer. However, I don’t generally recommend this approach because it involves deleting photos without having made a backup copy of the photos first.

More Detail: First and foremost, I don’t recommend deleting photos directly from a media card because doing so often involves deleting photos without having made a backup copy. If you later decide you wish you hadn’t deleted a given image, it would likely be too late to recover it (though there are still possible options for recovery). In other words, I don’t recommend deleting photos from media cards for pragmatic reasons, not because there is an inherent risk in doing so.

Whenever this subject comes up, I can count on hearing from photographers who insist that it is very dangerous to delete photos directly from a memory card, and that doing so will somehow scramble all the other photos on the card or cause other damage.

I’ve heard a lot of interesting explanations for why it is risky to erase photos from a memory card. All of those explanations have either relied upon anecdotal experiences that don’t prove a causal relationship between the deletion of photos or outdated information.

For example, a related piece recommendation suggests that media cards should never be formatted on the computer, but rather only in the camera that the memory card will be used in. As long as the format used on the computer, such as FAT32, is supported by the camera, there is no problem formatting on the computer.

The bottom line is that today’s cameras are well-designed and capable of managing data on a media card. There is no inherent risk in deleting photos directly from a media card, even though I don’t generally recommend the practice.

Accuracy of Planning


Today’s Question: I’m intrigued by the PhotoPills app you’ve referred to for planning photos featuring the moon or sun. In your experience, how accurate is the planning in terms of being able to precisely determine what the moon or sun will align with at the horizon?

Tim’s Quick Answer: The PhotoPills app is surprisingly accurate when it comes to planning for the specific position of the sun or moon. That is especially true when it comes to dealing with terrain. Dealing with man-made objects such as buildings.

More Detail: PhotoPills includes extensive detail about the position of the sun and moon, so you can plan for the specific timing and direction for sunrise, sunset, moonrise, and moonset. This enables you to determine, for example, the specific direction you will need to look to see the moon rise over the horizon.

That information can then be used to plan for an optimal location from which to photograph the sun or moon, so you can include a specific object within the frame along with the sun or moon. The map in the Planner pill within PhotoPills makes this possible, including satellite photo maps and terrain maps, among other options.

Of course, dealing with the height of objects that appear in the frame adds a layer of complexity. For example, even if the sunrise is at 6:00am, that doesn’t mean you’ll necessarily start seeing the sun at that time. If there is a mountain range in between you and the horizon, for example, you’ll need to take the elevation of the mountain range into account. This is relatively easy to accomplish with the geodetics feature in the Planner, so you can determine when the sun will rise high enough to get above the mountain range, for example.

The PhotoPills map doesn’t include information on the heights of buildings and other man-made objects, but you can still work around these issues by either looking up or estimating the height of such objects, and otherwise dealing with those objects in much the same way that you would deal with terrain.

These various topics are covered in my comprehensive video course on PhotoPills, which I encourage you to view before setting about the task of planning a photo with the app. You can get all the details of my “Photo Planning with PhotoPills” course with a discount included automatically by using this link to get started:


New Tablets from Xencelabs


Today’s Question: Have you seen the new tablets from Xencelabs, and had a chance to test them? If so, how do you think they stack up to the tablets from other manufacturers?

Tim’s Quick Answer: I have indeed tested out the tablets from Xencelabs and am very impressed. I’m using the medium size bundle (https://timgrey.me/tabletbundle), which includes the Quick Keys remote featuring a series of buttons and a dial that can be programmed for fast access to commonly used features.

More Detail: A tablet can be tremendously helpful for a variety of tasks, because it enables you to use a pen as an input device rather than a mouse, for example. A tablet can be especially helpful for photographers who are using Photoshop to optimize their images. To some extent a tablet can also be helpful in the context of Lightroom Classic, especially in conjunction with the Adjustment Brush for applying targeted adjustments.

The way I generally describe the benefit of a tablet is to suggest that you try to sign your name with a mouse, and then try to perform the same task with a pen on a tablet. You simply have better tactile control when using a pen rather than a mouse.

For tasks like dodging and burning, tracing along the edge of an object to define a selection, or painting in targeted adjustments, a tablet can be invaluable.

I’ve been using the Xencelabs medium tablet bundle and have been very impressed. The quality and accuracy of the tablet is excellent. The bundle also includes a Quick Keys remote, which I find very helpful. I typically use the dial control to adjust brush size, for example, with the other buttons providing the equivalent of keyboard shortcuts for commonly used tasks.

For me personally the tablet doesn’t completely replace a mouse, in part because I’ve gotten so used to using a mouse for other tasks over the years. But for tasks that involve any degree of drawing, a tablet is invaluable. The Xencelabs tablet medium bundle is now a fixture in my digital darkroom, and you can learn more about it here:


Backing Up Keywords


Today’s Question: Over the years I have developed a very strong keyword system, with many levels of nested keywords. When I am doing backups of the Lightroom Classic catalog, does the keyword file also get backed up?

Tim’s Quick Answer: When you back up the Lightroom Classic catalog the keywords are included as part of that backup. However, you may prefer to periodically create a discrete backup of just your keyword structure in addition to the catalog backup.

More Detail: While a backup of your Lightroom Classic catalog will include all the metadata assigned to your photos in the context of the catalog, that catalog backup still depends upon Lightroom Classic. In other words, the only way to make use of a backup catalog is to open that catalog with Lightroom Classic.

If you’d like to preserve your keyword structure beyond the scope of Lightroom Classic, and also make it possible to import those keywords into another catalog at any time, you can export your keywords from Lightroom Classic.

In Lightroom Classic you can go to the Library module and then from the menu choose Metadata > Export Keywords. In the dialog that appears navigate to the location where you would like to save your keyword backup, give the backup a name, and click the Save button.

The exported keywords will be stored in a text file that preserves all keywords represented by your Lightroom Classic catalog, including keyword hierarchies. You can later import that keyword list into a Lightroom Classic catalog with the Metadata > Import Keywords command on the menu.

Brush Lag in Photoshop


Today’s Question: For some time now whenever I’m using a brush tool in Photoshop the paint stroke lags way behind my mouse cursor. I assumed this would get fixed in an update, but the problem remains. Do you know if there is a way to resolve this issue?

Tim’s Quick Answer: The behavior you describe is a result of the Smoothing setting for the brush (on the Options bar in Photoshop) being set rather high. You can use a lower value for this setting to avoid the lag between the brush and your mouse cursor but note that your brush strokes won’t appear quite as smooth then.

More Detail: The Brush tool (and the related Pencil tool) include a Smoothing setting, which enables you to have Photoshop smooth out your brush strokes. For example, if you draw a basic “S” shape with the Brush tool you’ll likely find that the curves of the “S” don’t have perfectly smooth curves. Instead, you will probably see that there are minor bumps along the curve, depending on how smooth a hand you have.

For photographers who are using the Brush tool for things like dodging and burning, modifying a layer mask, and other tasks that involve general painting without necessarily needing perfectly smooth curves for each brush stroke, a high value for Smoothing is probably not going to provide much benefit. More to the point, a high value can cause a frustrating lag between the mouse cursor you’re painting with and the actual brush stroke that appears in your image in Photoshop.

Therefore, for photographers I recommend using a very low value for Smoothing, perhaps as low as 0% (which is what I use) but probably not higher than about 10% or so. This will minimize the behavior of Smoothing, so the brush strokes will follow your mouse cursor more closely.

Late Adoption of XMP


Today’s Question: I have used Lightroom Classic for years and have never checked the box to “automatically write changes into XMP” in the Metadata settings. I have over a hundred thousand photos. If I check this box, will all photos be subjected to this change? How long will it take? Will it affect my cloud backup?

Tim’s Quick Answer: When you turn on the “Automatically write changes into XMP” checkbox it will apply to all photos in your catalog and will work in the background. It won’t take very much time, and the files are quite small so it won’t have a significant impact on your backup.

More Detail: I recommend turning on the “Automatically write changes into XMP” checkbox, which can be found on the Metadata tab of the Catalog Settings dialog in Lightroom Classic. The checkbox is off by default, but I consider it advantageous to have the option turned on.

The primary reason I prefer to have this option enabled is that it provides a backup of your key metadata that you can recover from in the event of a corrupted catalog, for example. It also provides a degree of cross-application compatibility, such as enabling you to view key metadata values with other software such as Adobe Bridge.

When you turn this option on, Lightroom Classic will start updating all existing images in the background. In my experience even with a large number of photos the process takes less than thirty minutes. You can quit Lightroom Classic and the process will resume the next time you launch Lightroom Classic again.

The size of the XMP sidecar files for raw captures (or the increase in file size for other image types) is quite small, so updating a backup also won’t require significant additional space or time.

In other words, as far as I’m concerned there’s really no reason to leave this option turned off, and I recommend turning it on.

Electronic versus Mechanical Shutter


Today’s Question: I understand that using the electronic shutter on mirrorless cameras can extend the life of the mechanical shutter. But one of the problems with the electronic shutter is that for moving objects, they are likely to be distorted, which won’t happen when using the mechanical shutter. For static images where nothing is moving, is there any reason not to prefer the electronic shutter over the mechanical shutter?

Tim’s Quick Answer: In addition to using the mechanical shutter rather than the electronic shutter when photographing a moving subject, you may want to use the mechanical shutter when photographing under artificial light to avoid potential banding in the photo.

More Detail: Many mirrorless cameras include both an electronic and mechanical shutter, enabling you to choose which shutter is used at any time.

The electronic shutter provides the advantage of being completely silent, and in many cases also enables you to use faster shutter speeds than would be possible with the mechanical shutter. Favoring the electronic shutter can also help extend the life of the mechanical shutter mechanism.

However, because most cameras use a rolling sensor, where data is read line by line rather than all at once, using the electronic shutter when there is movement in the frame can lead to distortion. For example, you may have seen photos where the propeller blades of an airplane appear to be bent because of a rolling shutter. In addition, with some types of artificial lighting you can get a banded appearance in the photo due to flickering of the light that is not necessarily visible to the naked eye.

For situations where there is little or no motion in the frame, the electronic shutter will generally be best. Of course, at times you may need to use the electronic shutter to achieve a faster shutter speed than is possible with the mechanical shutter. In other cases you may choose to use the electronic shutter in order to allow for silent photography, even if there is a risk of some distortion.

If you’ll be photographing under artificial lighting you may want to opt for the mechanical shutter to ensure you don’t get banding in the photos or be sure to carefully check a test photo first to confirm that the lighting in question won’t result in this issue.

Overflow Storage


Today’s Question: I want to utilize an unused 4TB external drive to give some relief to my main 6TB drive. How exactly can this be accomplished, within Lightroom Classic, without creating any problems? I want to maintain the same folder structure for the photos that will reside on the new external drive. How best to distinguish between the old and the new drive? How best to avoid the “dreaded” question marks?

Tim’s Quick Answer: You can transfer photo and folders to a new external hard drive quite easily by first creating a new folder on the new hard drive and then dragging and dropping to that drive. The key being to make sure all this work is done within Lightroom Classic.

More Detail: One of the reasons that I find photographers get confused about moving photos from an existing hard drive to a new hard drive is that Lightroom Classic doesn’t show the new hard drive in the Folders section of the left panel in the Library module. That’s because Lightroom Classic only displays hard drives that actually contain photos being managed within the catalog.

When you want to make a new hard drive available within Lightroom Classic so you can move existing photos to that new drive, you first need to create a new folder on the drive. To do so, click on the plus (+) icon to the right of the Folders heading on the left panel in the Library module and choose “Add Folder” (not “Add Subfolder”) from the popup menu.

In the dialog that appears, navigate to the new hard drive you want to make available within Lightroom Classic. Then click the “New Folder” button at the bottom of the dialog and enter a name for the new folder. Since this will be a top-level folder in the context of your photos in Lightroom Classic, I suggest using a somewhat generic name such as “Photos”. If you want to designate that this storage location is something of an archive for overflow photos you could call the folder “Photo Archive”, for example. Click the Choose button to close the dialog after creating your new folder.

At this point the new folder you created will appear on the Folders list on the left panel in Lightroom Classic, under a heading representing the new hard drive. You can then drag-and-drop folders from the existing hard drive to the new folder on the new hard drive. You can also create other new folders on the new hard drive, such as to then move a subset of photos from a folder on the existing drive to a folder with the same (or similar) name on the new drive.

By virtue of doing all this work in Lightroom Classic, none of the photos or folders will go missing in the context of the catalog. And, of course, all of the changes you make in this way within Lightroom Classic will be reflected on the actual hard drive and through your operating system.

Does High ISO Cause Noise?


Today’s Question: I enjoyed your article on “Understanding ISO” in the November issue of Pixology. I had seen a video that suggested higher ISO settings don’t actually cause noise. What is your take on that idea?

Tim’s Quick Answer: With most cameras a higher ISO setting will result in more noise in the final image. The video in question focused on the fact that underexposure leads to noise, suggesting that the ISO setting played no role at all. But the ISO setting does impact noise levels.

More Detail: I often see photographers using semantics to try to make a claim that seems to contradict established knowledge in photography. This generally seems focused more on getting viewers to watch a video rather than on truly helping them understand an issue.

When you raise the ISO setting on a camera in order to maintain the same exposure you need to either use a faster shutter speed or use a smaller lens aperture. In other words, at a higher ISO setting you are capturing an image that is underexposed and then brightening the image through amplification.

It is true that underexposing an image will result in more noise. It is also true that amplification will result in more noise. But the fact of the matter is, increasing the ISO setting will increase noise levels with most cameras (a small number of cameras are ISO invariant, which mostly means they have excellent noise performance overall).

In addition, it is worth noting that using the ISO setting to increase the overall exposure is better than underexposing an image without raising the ISO setting. That is because in-camera amplification of the signal recorded by the image sensor results in less noise that post-capture brightening of the image.

So, raising the ISO setting will increase noise levels for most cameras in most circumstances. But generally speaking, the benefit of raising the ISO setting is greater than the risk of noise, in terms of being able to ensure a fast enough shutter speed to avoid motion blur or not having enough depth of field.

You can learn more about the ISO setting as it relates to exposure in the November 2021 issue of Pixology magazine. If you’re not already a subscriber, you can learn more about Pixology on the GreyLearning website here: