Category: Ask Tim Grey

Today’s Question: [In response to the answer from February 15th regarding sharing images for high-resolution displays] What about PPI [pixel per inch resolution]? 1000 pixels measures differently at say 72 PPI than 110 PPI, and our re-sizing applications do ask for both resolution and pixel dimensions.

Tim’s Quick Answer: The pixel per inch (PPI) resolution is only truly applicable when printing an image. For digital sharing only the actual pixel dimensions matter, and the PPI resolution can essentially be ignored.

More Detail: When sharing a photo, you want to be sure that the size of the image is large enough to appear with good quality using the intended output method. Ultimately, all that means is that you need to have enough pixels in the image. The pixel-per-inch (PPI) resolution is effectively irrelevant.

The PPI measurement for resolution is really just a shorthand. Instead of saying that an image is “3,000 by 2,400 pixels” you can say the image is “10-inches by 8-inches at 300 pixels per inch”. The latter is just a method of describing the pixel dimensions in a way that is easier to translate to the final output.

However, the PPI resolution for an image really only applies when the image is being printed. If the image is being shared digitally, all that matters are the pixel dimensions, not the metadata setting that defines the PPI resolution.

For example, if a monitor display features a resolution that is 2,000 pixels across and you resize an image to be 1,000 pixels across, the image will by default be displayed at a size that is half the width of the monitor display. The number of pixels in conjunction with the physical pixel dimensions of the monitor display determines how the size at which the image will be presented.

Obviously, the software being used to display the image could alter the presentation of the image, such as by displaying the image larger or smaller than the actual pixel dimensions call for. But when preparing an image for digital sharing you only need to consider the actual pixel dimensions, not the PPI resolution value stored in metadata.

In fact, even when printing an image, the PPI resolution value is really just a number in metadata. The print quality depends upon having enough pixels in the source image to produce the intended output size based on how the output is being rendered by the printer. If you have enough pixels in the source image for the intended print size, a good quality print will be the result regardless of what the PPI resolution in metadata was set to.

Again, the PPI value really just provides a way to talk about the output size in more real-world terms. Producing output of good quality simply requires enough pixels for that output.

Note, by the way, that today’s question was a follow-up to an answer in a previous edition of the Ask Tim Grey eNewsletter, which you can find here:

https://asktimgrey.com/2022/02/15/high-resolution-sharing/

Today’s Question: How do you feel about photographers who use Photoshop filters or textures heavily on their photos?

Tim’s Quick Answer: While I don’t personally tend to apply a lot of filters, textures, or other creative effects that take a photo beyond the typical appearance of a photo, when these effects are done well they can produce very nice artistic images.

More Detail: I think it can be important to distinguish between a somewhat “normal” interpretation of a photograph and an artistic interpretation that happens to have been created in part from a photographic image. Neither of these is inherently better than the other, they are simply different.

Creating a great image is not necessarily easy. In my view it is especially difficult to create a great image when applying strong filters or textures to a photo. It is very common, in my experience, for a photo with these types of effects to quickly take on an appearance of being over-processed that can detract from the aesthetics of the image.

For photographers who are interested in taking their photos beyond the look of a “normal” photograph I think it is important to have a clear vision for what they are trying to produce. I also think it is important to consider that if you’re using Photoshop filters as the foundation of your creative effects, for example, those filters are relatively limited in number and there is a risk that the image will be perceived as having had filters applied to it rather than being appreciated for the aesthetic of the result.

Of course, ultimately it doesn’t matter what I think about specific ways of creatively interpreting a photo. I’ve seen a great many images that started as a photograph (or multiple photographs) and were transformed into incredible pieces of art. I’ve also seen many images that lacked a creative look in part because common Photoshop filters were applied to them. As with any form of artistic impression, it is up to the artist to decide what they like and what they want to produce, and to create the best art they can and then (hopefully) share their vision with others.

By the way, this question was asked in response to my recent webinar presentation on “The Best Photo Tips I Ever Learned”. You can view a recording of the full presentation here:

https://youtu.be/usaQn2GD6ns

Today’s Question: Like you I upgraded to a MacBook Pro with only two USB-C ports, one of which gets used for power. I got a USB hub to expand the number of ports, but hard drives with a USB-C connection don’t work with this hub. Is there a way to get more ports that will work with external hard drives?

Tim’s Quick Answer: The key here is to use a powered USB hub, so that the hub can provide more power than would otherwise be available from the port the hub is connected to.

More Detail: As I’ve noted previously, about the only shortcoming of my MacBook Pro laptop featuring the high-performance Apple M1 processor is that there are only two USB-C data ports on this laptop, and one of them is generally used for power. In other words, I only really have a single data port available much of the time.

A USB hub provides a solution for expanding the number of ports available on a computer, but this isn’t as easy a solution as it might seem if you want to use bus-powered hard drives or other peripherals requiring power in conjunction with a hub that doesn’t have an external power source.

There are a variety of powered USB hubs available, but I was looking for something that would work well with my configuration. Specifically, I wanted the hub to connect to USB-C, and provide power for at least one USB-C port and a couple of USB-A ports.

The USB hub I’ve been using (and happy with) is an Anker model that features power input via a USB-C connector, an additional USB-C data connection, two USB-A data ports, SD card reader, HDMI output for a second monitor display, and more.

You can learn more about the hub I’m using on the GreyLearning blog here:

https://greylearningblog.com/powered-usb-hub-for-more-ports/

Today’s Question: Some time ago I was told to always quit Lightroom Classic before doing a full backup. But I don’t remember where or why. So, is it OK to run a full backup while Lightroom Classic is open, or should it be shut down first?

Tim’s Quick Answer: I consider it perfectly safe to run a backup while using other software, including Lightroom Classic. However, I do recommend minimizing the use of software (including Lightroom Classic) that could be making changes while a backup is running.

More Detail: I’ve never seen any indication that running a backup while other software is making changes to files that are being backed up will create any problems at all. There will likely be some degree of performance degradation, but that isn’t generally a significant concern.

If there are changes being made while the backup is running, there is a chance that the backup won’t be completely up to date when it completes. But simply running the backup job again later will resolve that issue.

In the case of Lightroom Classic in particular there is a risk that the catalog may be updated during a backup, or that images (or XMP sidecar files for raw captures) may be updated in the background during a backup. These don’t present any real concern of corruption of files or of the backup.

So, I prefer to keep my computer idle without any other applications running when performing a backup, but it is not critical to take this approach.

Note, by the way, that there have been numerous times when I have needed to work while backing up a hard drive with GoodSync (http://timgrey.me/greybackup), and I most certainly continue working even while my cloud-based backup is being updated by Backblaze (https://timgrey.me/onlinebackup).

Today’s Question: In follow up to reading about your life plan to only have a laptop, I was wondering how or when you made the decision to replace the old laptop with a new one?

Tim’s Quick Answer: In my view there’s no need to consider replacing a laptop unless there’s a clear benefit in terms of performance or user experience.

More Detail: When I recently replaced my laptop my existing laptop was already a few years old, but I was still happy with the overall performance and specifications. However, I started having some hardware issues including problems with the keyboard and USB ports that started to be unreliable. These are certainly issues that could have been fixed, but I decided to invest in a new laptop rather than upgrade my existing laptop.

Having hardware problems obviously impacts the user experience, but often these issues can be resolved with a repair. While I was happy with the performance of my prior laptop, I knew the newer model would provide a considerable performance boost, in part because it included the new Apple M1 processor.

Another factor that impacted my decision was that I was able to get a surprisingly good trade-in value for my existing laptop. Since I was eager to test out the new M1 processor anyway, this sealed the deal for me, and I opted to upgrade.

It can be challenging to evaluate new features, upgraded performance specifications, and more, without actually getting an opportunity to do a hands-on test of the new computer. Fortunately, I was able to perform some basic testing, and could also review performance tests online, so I knew I would be happy with the new computer.

Each user is different in terms of how various considerations are weighed. If money is no object, you could certainly upgrade your computer on a regular basis. I tend to feel that it is worth considering replacing a laptop after around three years or so, but only based on an evaluation of what is available at that point and how it will improve your experience by upgrading to a new computer.

My laptop of choice is a MacBook Pro, and you can get the details of a nicely equipped 14-inch model (a 16-inch model is also available) here:

https://bhpho.to/3oJPM91

Today’s Question: With newer high-resolution monitors, what now would be the acceptable photo resolution standard for online sharing? I recently purchased a new computer, and the recommended resolution for the monitor is 3840×2160 pixels. This setting is larger than my old monitor of 1920×1440. Now when I view my website, I find the photos are quite small. I usually keep my website jpeg photos in the 1050×800 range.

Tim’s Quick Answer: I still tend to use a resolution of around 1,000 pixels on the long side, in part because most website visitors are not using extremely high-resolution displays. I also suggest using responsive web design whenever possible for sharing photos online.

More Detail: Sizing photos for online sharing involves striking a balance between an image that is large enough for viewers to see well but not so large that a stolen image could be printed at a large size.

I tend to size photos to around 1,000 pixels on the long side when sharing online. This generally ensures the image will be at a reasonable size for viewing, without being so large that the image could be printed at a large size.

The statistics I’ve been able to locate indicate that around 60% of website visitors worldwide are using a display resolution of 1920×1080 pixels or lower. Many who have a higher resolution display, myself included, tend to operate that display at a resolution lower than the maximum.

For typical resolution settings an image sized to around 1,000 pixels on the long side will fill about one-quarter of the screen. On a display with a 4K resolution that image would only fill about one-sixteenth of the screen. However, most web browsers allow you to zoom in on a page you’re browsing, and if the photo is shared on a page that employs responsive web design (which includes many blog site templates, for example), then the image will appear at a similar size regardless of display resolution.

If you’re more concerned about having a relatively large display for your photos and not too concerned about the potential for your photos to be stolen and printed at a moderately large size, you could increase the resolution for the photos to 2,000 pixels on the long side. This would provide an image that is about full-screen for the typical website visitor, and about one-quarter of the screen for someone using a 4K display. Note that an image shared at this higher resolution could be printed up to 4″x6″ at excellent quality, and up to around 8″x10″ with very good quality.

Today’s Question: When I use a selection tool [in Photoshop or Photoshop Elements] that produces the “marching ants,” such as the Lasso tool or Quick Selection tool, the selection outline is so light I can hardly see it. Is there a setting that allows me to darken them?

Tim’s Quick Answer: While you can’t alter the “marching ants” animated dashed line that represents the selection outline, you can use Quick Mask mode as an option for being able to better see the selection area.

More Detail: Quick Mask mode is a feature in Photoshop that provides an alternative way of viewing and modifying selections, and while it isn’t exactly an included feature in Photoshop Elements, it can be accessed there as well. When you activate Quick Mask mode by default you’ll see a translucent red overlay over non-selected areas of the image, with selected areas appearing normally.

In Photoshop you can switch to Quick Mask mode by pressing the letter “Q” on the keyboard, or by clicking the button at the bottom of the toolbar that has an icon of a dashed circle within a rectangle. If you double-click on that button on the toolbar you can bring up a dialog that enables you to change the color display settings for Quick Mask mode.

In Photoshop Elements there isn’t a Quick Mask button on the toolbar, but you can still access Quick Mask mode with a little workaround. After creating a selection, regardless of which tool you’ve used, switch to the Selection Brush tool. This is found along with the Quick Selection tool, so you can start by selecting the Quick Selection tool from the toolbar and then click the Selection Brush button at the left side of the Tool Options panel.

To the right of the Add and Subtract options on the Tool Options panel you’ll find a popup with a default value of “Selection”. Change that to “Mask” and you’ll see the equivalent of Quick Mask mode. You can switch to a different tool or change the popup back to “Selection” to hide this Quick Mask display.

I would certainly appreciate it if Adobe would provide some better options for making the animated dashed line that represents selections in Photoshop and Photoshop Elements easier to see. But in the meantime, the Quick Mask mode option can be helpful for evaluating and modifying selections.

Today’s Question: I am getting ready to replace my aged MacPro and am seriously considering buying the new MacBook Pro with a M1 max chip as it seems to be the best thing around. My plan would be to use it as my desktop as well as when I go on the road. Your thoughts on this? If you use the M1 MacBook Pro as a desktop, how do you set it up with external monitors, keyboard, mouse, and hard drives?

Tim’s Quick Answer: I have used a laptop as my only computer for about fifteen years now, and absolutely love this approach. I can be mobile with the laptop, and when I’m home I have a monitor, keyboard, and mouse that I use for convenience.

More Detail: I adopted the approach of using a laptop as my only computer simply because I was traveling so extensively that it didn’t make sense to keep a desktop computer at home. What I’ve learned along the way is that it can be incredibly convenient to use a laptop exclusively.

By using a laptop as my only computer, all my key files and applications stored on the internal hard drive are available to me anywhere, as long as I’ve brought my laptop with me. For example, my Lightroom Classic catalog is on my laptop’s internal hard drive, so if I have my laptop, I have my catalog.

When I’m home I connect an external monitor, but I keep my laptop open so that I have the benefit of two displays. I use the external monitor as my primary display in this context, with the laptop providing a supplemental display.

I use an external keyboard and mouse (I use the Apple Magic Mouse, https://bhpho.to/3uydSYn) for convenience as well, both of which connect wirelessly via Bluetooth. This enables me to keep the laptop off to the side so I can focus on the external monitor in front of me.

I keep my photos and much of my other important data on external hard drives, which I can bring with me when traveling if needed. Regardless of where I happen to be, I can connect external hard drives directly or via a USB hub if I need to connect multiple drives at once.

Especially since the latest laptops are quite powerful, I don’t feel any need to consider a desktop computer. As far as I’m concerned, a laptop is the only type of computer I need. The Apple M1 processor also provides excellent performance, as noted in a previous answer.

You can find a MacBook Pro with M1 processor outfitted nicely (with additional options for upgrade or expansion) here:

https://bhpho.to/3orGUoK

Today’s Question: I wish to change the name of my Lightroom Classic catalog. Its name has lengthened every time Adobe adds an update. Can you explain how to rename the catalog safely?

Tim’s Quick Answer: To rename the Lightroom Classic catalog you actually need to rename a series of files with a similar base filename structure, so it is important to be careful with this process.

More Detail: The Lightroom Classic catalog consists of more than just a single catalog file, but rather includes a series of “helper” files as well. If you want to rename the catalog you need to also rename the helper files using the same base filename structure.

To get started you need to know where the catalog files are stored. Fortunately, this is easy to determine from within Lightroom Classic. First, choose Edit > Catalog Settings from the menu to bring up the Catalog Settings dialog. Then go to the General tab and click the Show button to the right of the Location field in the Information section. That will open a window in the operating system showing the location where the folder for the catalog is stored, with that folder highlighted.

Before you start renaming the catalog files you need to quit Lightroom Classic, so be sure to do that next. Then double-click on the folder that contains the catalog files.

The actual catalog file has a filename extension of “.lrcat”. You’ll also find a series of files with an “.lrdata” filename extension, with the specific number of these files depending on which features you’ve taken advantage of. For example, if you have generated Smart Previews within Lightroom Classic you’ll find an lrdata file for those Smart Previews. With the latest update to Lightroom Classic you’ll also find a file with a filename extension of “.lrcat-data”.

The lrcat and lrcat-data files will have the same base filename. The files with the lrdata filename extension will have that same base filename, along with one or more words appended to the filename. The portion of all of the filenames that matches the lrcat file must be renamed in exactly the same way for all files.

I recommend that you start with the lrcat file. You can right-click on the file and choose the rename command. Then type any name you’d like for the catalog file. You can then select that filename and copy it to the clipboard by pressing Ctrl+C on Windows or Command+C on Macintosh. Next, rename the lrcat-data file and paste the copied filename to replace the existing filename.

For the lrdata files you’ll need to be a little more careful. You need to replace the portion of the filename that matches the previous name for your catalog, while retaining the additional text after that filename.

For example, let’s assume your catalog was called “My Catalog.lrcat”, and you rename that to “Lightroom Catalog.lrcat”. One of the helper files will be the previews file, which in this example would have a filename of “My Catalog Previews.lrdata”. You need to rename that file to “Lightroom Catalog Previews.lrdata”, retaining the ” Previews” text (including the space) while replacing the “My Catalog” text. Repeat this process for all of the catalog helper files.

When you’re finished you can double-click the newly renamed lrcat file to launch Lightroom Classic with that catalog.

Today’s Question: How much can you safely upsize an image without sacrificing noticeable quality degradation? And what is the best resampling method for upsizing? Bilinear, Bicubic, or Lanczos?

Tim’s Quick Answer: As a very general rule you can enlarge a photo to double the horizontal and vertical dimensions (quadruple the total area), though the specifics depend on how the image will be shared. I recommend the Bicubic interpolation algorithm in most cases.

More Detail: There really isn’t any strict rule about how large you can print a photo while maintaining good quality. As I often explain when it comes to this topic, you can make a photo infinitely large as long as the viewer will be extremely far away from the image. If you don’t get too close to an extreme enlargement, you won’t be able to perceive the degraded image quality.

In most cases, however, I assume that when a photographer wants to know how much they can safely enlarge a photo it is with the assumption that the viewer will be able to get relatively close to the enlarged image.

In my experience as long as the source image is of good quality in terms of sharpness, detail, and minimal noise, you can comfortably enlarge a photo to double the height and width (quadruple the total image area) while maintaining good image quality. That’s not to say you can’t produce great results with an even bigger enlargement, but doubling the dimensions will generally ensure good image quality in the enlargement.

When it comes to the interpolation algorithm used for enlargement, in general I recommend the bicubic algorithm. For significant enlargements Photoshop includes a “Bicubic Smoother” algorithm, which can be advantages for especially significant enlargements.

The Lanczos algorithm is also considered to be very good, though it is most commonly used for enlarging video rather than still photos. There is a risk of contrast artifacts along edges within a photo when using Lanczos, which is why I tend to favor Bicubic.

There are also third-party tools such as Gigapixel AI from Topaz Labs that use methods that go beyond simple algorithms, which can also improve results when creating significant enlargements of a photo.