Camera versus Eyes


Today’s Question: I’ve been told that a digital camera can’t capture as much information as human vision. Is that true?

Tim’s Quick Answer: I would say that a digital camera can actually capture more information than normal human vision is capable of, though perception can be a bit different from this.

More Detail: I most often hear the suggestion that human vision is “better” than a digital camera in the context of high dynamic range (HDR) photography. The suggestion is that by creating an HDR image you are matching the advanced capabilities of human vision. Instead, I would say that HDR photography reproduces the illusion of human vision.

The reason we might perceive human vision as having greater dynamic range and greater depth of field than a digital camera is that our eyes are constantly adjusting in terms of exposure and focal point as we move our view around a scene.

A classic example of the limitations of human vision is illustrated by walking out of a dark movie theater into daylight. It takes a minute or two for our eyes to adjust from a dark environment to a very bright environment, which illustrates that the dynamic range of our vision isn’t really all that significant. Rather, as we move our eyes around a scene with varying light levels, our pupils adjust to effectively alter the exposure of our vision.

Similarly, as we move our eyes around a scene, our focal point changes rapidly, providing the illusion of tremendous depth of field. We actually see a very small area of a scene to be in perfect focus, both in terms of depth and field of view.

So, in general I would say that a digital camera is actually able to capture more information in terms of dynamic range and depth of field, when compared to normal human vision. The difference is that human vision is simply making constant adjustments, while a digital photo preserves a single (hopefully decisive) moment in time.

Exposure Too Long?


Today’s Question: I’m planning to purchase a solid neutral density filter, and I’m not sure how strong a filter I should get. Is there such thing as a long exposure that is too long?

Tim’s Quick Answer: It is most certainly possible to have an exposure that is too long in terms of the effect created in the photo. As a result, it is important to be thoughtful about the strength you might need in a solid neutral density filter. As a very general rule I recommend a six-stop filter as a good place to start, but the best option depends on the nature of your photography as well as your personal preferences.

More Detail: When you use a long exposure for a photo, any motion within the scene will be rendered with a blur effect. For example, flowing water will take on a very smooth and silky appearance rather than potentially having more texture and detail.

One of the mistakes I sometimes see photographers making is to assume that if a long exposure is good, that an extremely long exposure is better. That is not always the case.

To be sure, there isn’t a single “right” decision here. In many respects a very long exposure can be just as pleasing as (or even more pleasing than) an exposure that isn’t quite as long. But more often than not, when comparing a moderately long exposure with an extremely long exposure, I tend to favor the exposure with the duration that wasn’t quite as long.

With an extremely long exposure, significant detail may be lost in areas where there was movement in the frame. In some cases subject matter within the frame might disappear altogether. Sometimes these are good things, but often they are not.

The optimal exposure time will vary based on the circumstances within the scene you’re photographing, as well as your own personal preferences. There is quite simply no replacement for experimentation and evaluation. Take a variety of exposures with different durations and see what you like.

For daylight conditions I will periodically use a very strong ten-stop neutral density filter. For more typical scenarios I will use a neutral density filter that is no stronger than six stops. And in some cases I will raise the ISO setting (or open the lens aperture) in order to shorten the exposure a bit more than the filter would typically call for.

The filter I’ve been making the most of recently is a six-stop neutral density filter from B+W Filters, which you can find here:

Light or Dark Display?


Today’s Question: I just updated to the “Mojave” version of the Macintosh operating system, and one of the big features being touted is the option for a dark interface display. Do you recommend using this darker version of the interface, or is the bright version better?

Tim’s Quick Answer: In general I recommend evaluating your photos against a neutral backdrop, ideally with a luminance value that is reasonably close to 50% gray. The “Light” appearance option for MacOS Mojave is actually a little closer to this, so I recommend that over the “Dark” option. For practical purposes, however, this is a moot point since the interface of most software (such as Lightroom or Photoshop) will override the operating system configuration.

More Detail: The new MacOS Mojave includes a new Appearance setting on the General page of the System Preferences dialog, which allows you to choose between a Light versus Dark interface appearance. The Light setting represents the existing interface configuration users will be familiar with, while the new Dark setting provides a considerably darker overall interface.

If the interface is too dark, you’ll tend to perceive the image as being brighter than it is, and will adjust the image to be too dark. If the interface is too bright, you’ll perceive the image as being darker than it is, and will adjust the image to be too bright. All of this assumes, of course, that you’ve properly calibrated your monitor display.

I recommend evaluating your photos against a neutral gray backdrop, that is as close to a 50% gray value as possible. Generally speaking, however, the operating system setting won’t have a significant impact on this issue. That’s because most software (such as Photoshop and Lightroom) provide their own interface settings that effectively ignore the operating system configuration.

As a result, you’ll generally want to take a look at the configuration for the software you’re using to optimize your photos, to ensure the best display of the photos you’re working on. It is also important to make sure your display is properly calibrated, using a hardware device such as the X-Rite ColorMunki Display, which you can find here:

DxO Bankruptcy


Today’s Question: I just saw an article indicating that DxO Labs, the current owner of the Nik Collection, has filed for bankruptcy. Are you concerned this could mean the end of the Nik Collection forever?

Tim’s Quick Answer: I’m not too concerned, for two reasons. One, I suspect that this bankruptcy (or receivership) may have been primarily the result of poor sales of the DxO One camera for the iPhone. Two, the Nik Collection update from DxO Labs helped ensure the software would run on most computer configurations, which in turn means there’s a good chance this software will continue to function for some time even if there aren’t any future updates.

More Detail: Naturally whenever a company files for any form of bankruptcy protection it is reasonable to be concerned that the company will go out of business altogether. At least for now, that doesn’t appear to be the case with DxO Labs.

DxO Labs filed for bankruptcy protection in March of this year. A press release issued at the time (though since removed from the DxO Labs website) indicated the process was only expected to last for a few weeks. All indications are that the company is continuing to operate normally, more than six months after the initial filing.

DxO Labs also announced in June that the DxO One camera for the iPhone was being discontinued. I suspect this provides a clue about what may be the core reason for the bankruptcy filing. Selling hardware, after all, can be a considerably more expensive and challenging business than selling software.

So, it remains to be seen if there will be any additional negative implications from this situation, but for now it seems DxO Labs continues to operate normally, at least as far as the software business is concerned.

If you have purchased the Nik Collection from DxO Software, note that I have produced a comprehensive video course that covers the full collection. This course can be found on the GreyLearning website here:

Browsing Previous Import


Today’s Question: You recently referred to the option in Lightroom Classic to turn off the setting that causes Lightroom to automatically browse the set of photos from the last import instead of the current folder. Do you recommend having that setting turned off or on?

Tim’s Quick Answer: I prefer to have the option to browse the most recently import photos turned on in the (perhaps overly optimistic) hope that it will help ensure I review all photos promptly after import, in order to identify my favorites (versus outtakes) from each day’s photography.

More Detail: As I mentioned in a recent edition of the Ask Tim Grey eNewsletter, by default when you import photos into Lightroom Classic it will automatically switch you to the “Previous Import” collection (or the “Current Import” while the import operation is still in progress). You can turn this option off on the General tab of the Preferences dialog if you prefer.

I like to have this option enabled, so that I am able to automatically browse only the photos I’ve just imported, each time I perform an import operation. The idea is that this setting will help increase the chances that I will stay organized and up-to-date by reviewing each batch of photos as soon as they are imported.

Ideally, my workflow involves importing photos, and then immediately reviewing those latest photos to identify favorites and outtakes. If I’m able to keep up with this workflow, it means I am easily able to browse the photos I’ve not yet reviewed, and I’ll ensure that by the end of a photo trip I’ve reviewed all photos captured along the way.

Of course, sometimes I import more than one batch of photos in a single sitting. And in other cases I might not have enough time (or energy) to review all of the photos I’ve just imported, before it is time to import more photos. But I do find that having Lightroom switch to browse the photos that were just imported helps ensure I am more consistent about reviewing photos promptly after importing them.

Other photographers find it a bit distracting to have Lightroom switch them from viewing a given folder to viewing the most recently imported photos. They may be browsing photos in the same folder they are importing into, for example, and want to continue browsing those existing photos along with the new captures as they are imported. In that case, you can most certainly turn off the “Select the ‘Current/Previous Import’ collection during import” checkbox on the General tab of the Preferences dialog in Lightroom Classic.

Dfine Noise Reduction Quality


Today’s Question: Your new course on the Nik Collection from DxO got me interested in this bundle of plug-ins again. I’m wondering, however, what you think of the quality of the noise reduction with the Dfine plug-in included in the Nik Collection. Do you think it is at the same level as other software?

Tim’s Quick Answer: I don’t consider the noise reduction in Dfine (part of the Nik Collection now offered by DxO Software) to be particularly good. I recommend using other tools (such as Lightroom, Camera Raw, or third-party apps) for noise reduction, rather than using Dfine.

More Detail: While I’m impressed with the overall quality of the plug-ins in the Nik Collection by DxO, it is also worth noting that these applications haven’t been significantly updated in quite some time. There have been very few new features or other meaningful updates in the last few years. As a result, other software has improved to the point that in some cases other tools will provide better results.

To be sure, HDR Efex Pro still does a very good job of assembling high dynamic range (HDR) images. However, as noted in an earlier edition of the Ask Tim Grey eNewsletter, I’ve been more impressed recently with the results I’ve achieved with Aurora HDR (

I also still very much like what is possible with Silver Efex Pro and Analog Efex Pro, and often find very interesting effects available with Color Efex Pro. So there is still great value in the Nik Collection, especially when it comes to applying creative effects to photos.

Unfortunately, there have not been any real updates to the Dfine plug-in, so the noise reduction quality with this application is not on par with more recent offerings.

I’ve found that Adobe Camera Raw and Lightroom provide excellent results in terms of noise reduction, and there are several third-party plug-ins that provide great results as well. However, Dfine is not an application I would recommend for noise reduction.

Incorrect Sort Order


Today’s Question: When importing my memory cards into Lightroom, the photos are not in the correct order. Please help, I’m very frustrated.

Tim’s Quick Answer: When you initially import photos into Lightroom, the photos will generally be sorted based on the order they were actually added to the catalog. This can sometimes be significantly different from the order in which you captured the photos. However, you can change the sort order to “Capture Time” to resolve this issue.

More Detail: When you import photos to Lightroom (or otherwise download photos) from a memory card, they will not always be copied in the order the photos were captured. This can be caused by a variety of factors, including the way information is written to flash storage devices (such as the memory cards we use in our digital cameras).

You can correct the sort order to something more meaningful (such as based on the capture time) using the Sort popup on the toolbar below the Grid view display. If you’re not already in the Grid view you can press the letter “G” on the keyboard to switch to this display option. Then click the Sort popup and choose the preferred option. I generally prefer the “Capture Time” sort order, so my photos are displayed in the same order I captured them.

Note that the “Added Order” sort setting is a unique “feature” related to the import process. If you are importing to an existing folder, there is an option to keep your view on that folder, which in turn means you’ll retain the established sort order. To do so, turn off the “Select the ‘Current/Previous Import’ collection during import” checkbox on the General tab of the Preferences dialog in Lightroom.

Navigation Shortcuts


Today’s Question: In the Photoshop Quick Tips course, episode 4 “Panning by Sections” explains how to move segment by segment through an image by pressing CMD + Page Down on a Mac.  But what if you have a MacBook? There is no Page Down key on the keyboard.

Tim’s Quick Answer: On Macintosh computers without a Page Up or Page Down key on the keyboard, you can use the “fn” key in conjunction with the up and down arrows to achieve the same effect. This will enable you to use the panning technique for navigating among an image in sections within Photoshop.

More Detail: As noted in Lesson 4 of my “Photoshop Quick Tips” course, you can pan around an image in Photoshop in sections when you are zoomed in, by using the Page Up and Page Down keys. If you add the Ctrl key on Windows or the Command key on Macintosh, that panning in sections will move horizontally rather than vertically.

On MacBook computers (as well as some other laptop computers) there is no Page Up or Page Down key, due to the smaller keyboard. However, there will generally be some form of “function” key that can be used in conjunction with another key on the keyboard to achieve the effect of Page Up or Page Down. In the case of the MacBook the arrow keys provide this solution.

So, you can hold the “fn” key and press the up arrow key to move up one section, or the “fn” key with the down arrow key to move down one section. You can hold the “fn” key along with the Command key so that the up and down arrow keys will cause your view to move left and right, respectively.

This panning is helpful when you want to zoom in on an image to evaluate for blemishes or other issues, and you want to be sure to pan through every section (and thus every pixel) in the image.

Note that my “Photoshop Quick Tips” course is included in the “Quick Tips Bundle”, which also includes “Photo Gear Quick Tips” and “Lightroom Quick Tips” (and more courses soon). You can find the bundle here:

Lockup for Sensor Cleaning


Today’s Question: Just read today’s Q&A about mirror lock up. Isn’t mirror lock up also used during sensor cleaning?

Tim’s Quick Answer: In a manner of speaking, yes, mirror lockup is used for sensor cleaning. The difference is that in the case of sensor cleaning mirror lockup is handled for you automatically, and is accessed separately from the actual mirror lockup feature.

More Detail: To clean the image sensor on a digital SLR, you of course need to access the actual image sensor. When the camera is not actively capturing a photo, the mirror that enables you to see through the lens will be blocking the image sensor. So, for manual sensor cleaning the mirror must be moved out of the way of the sensor.

In concept, this is very similar to the mirror lockup feature discussed in Monday’s edition of the Ask Tim Grey eNewsletter. However, in this context the mirror is moved with a different feature.

When you enable mirror lockup, you will press the shutter release button twice to capture a photo. The first time you press the shutter release button the mirror will be locked in the “up” position. The second time you press the shutter release button the photo will be captured. This enables you to delay the capture until the vibrations from the mirror movement have subsided.

When you activate the manual sensor cleaning mode for a digital SLR, the mirror will similarly be moved up and out of the way so you can access the image sensor for cleaning. This is essentially the same feature as mirror lockup, simply used in a different context. When you are finished cleaning the sensor, turning off the camera’s power will move the mirror back to the “normal” position.

Note, by the way, that when we use the term “sensor cleaning” we are really referring to cleaning the filter that is mounted in front of the actual image sensor in the camera. And as I hope goes without saying, it is critically important to be extremely careful if you choose to clean the sensor on your own camera, as there is a risk of damage that would not be covered by the warranty (or extended warranty) for your camera.

Deleting Smart Previews


Today’s Question: My computer is running out of storage space. Can I delete the smart previews from my catalog? Can I delete them from the folder that contains my Lightroom catalog, or should I do it within Lightroom?

Tim’s Quick Answer: To delete Smart Previews in Lightroom, I recommend Using the menu command Library > Previews > Discard Smart Previews. You can first navigate to the folder that contains the photos you want to remove Smart Previews for, or even choose the All Photographs collection in the Catalog section of the left panel in the Library module. Then choose the Discard Smart Previews command, and choose the “Discard All” option if you want to discard previews for all photos in the current location.

More Detail: In theory you could simply delete the Smart Previews file from the folder where your Lightroom catalog is stored. However, because you are able to work offline in the Develop module with Smart Previews, there is some risk that you could lose changes you’ve applied to photos based on Smart Previews.

Instead, I recommend using the Discard Smart Previews command from within Lightroom. First navigate to the location that contains the photos you want to discard previews for. As noted above, you could also select the “All Photographs” collection from the Catalog section of the left panel in the Library module if you want to discard all Smart Previews for all photos in your catalog.

You can then choose Library > Previews > Discard Smart Previews from the menu. In the confirmation dialog you can choose Discard All if you want to discard Smart Previews for all photos from the current location, rather than only the selected photos.

I do recommend performing a optimization of your Lightroom catalog after performing this type of task, which can help optimize the catalog and improve performance. This is an option available when you perform a catalog backup in Lightroom, but you can also choose File > Optimize Catalog from the menu to begin the optimization process.