Category: Ask Tim Grey

Today’s Question: Is Adobe DNG better than TIFF? I saw an advertisement that indicated that the default file format when taking pictures is typically JPG or TIFF, both of which have limited editing options. It went on to explain that Adobe DNG was an uncompressed raw file format with higher quality image than a JPG or TIFF and greater editing capabilities.

Tim’s Quick Answer: In the context of capturing photos, I would say that Adobe DNG is indeed somewhat better than TIFF. DNG is also most certainly better than JPEG in terms of overall image quality and flexibility. In general I would say that DNG is on par with proprietary RAW capture formats in terms of image quality and post-processing flexibility.

More Detail: In a general way you can think of the Adobe DNG (Digital Negative) file format as being a variation on a proprietary RAW capture, minus the “proprietary” element. That is because the Adobe DNG format is openly documented by Adobe, which is aimed at providing a degree of peace of mind for photographers.

A variety of cameras now offer the Adobe DNG format as a capture option within the camera. Many cameras also offer proprietary RAW capture formats. Virtually all cameras support JPEG capture, and some cameras support the TIFF file format for capture (though this is becoming a rare option to find in a camera).

I would say that if your camera offers a RAW or DNG capture option, that is always your best choice in terms of potential image quality and flexibility in post-processing. The TIFF file format will generally provide very good image quality, but with a file size that is about three times (or more) larger than a RAW or DNG capture file without as much flexibility in post-processing. In other words, as a general rule I never recommend using the TIFF capture option in any camera that supports this option.

The JPEG capture option will provide the lowest quality with the least amount of flexibility in post-processing. That doesn’t automatically make JPEG capture a bad thing, but it certainly represents a compromise.

So in general I would say that I do agree with the statements included as part of today’s question. I would just hasten to add that if there is a proprietary RAW capture format available in your camera that will provide the same potential benefits as an Adobe DNG capture in terms of capture quality and post-processing flexibility.

Some photographers feel more comfortable using the Adobe DNG format compared to proprietary RAW capture formats, because the former is openly documented. Other photographers prefer to employ the proprietary RAW capture format, such as to take advantage of special features that are only available with that capture option combined with the software provided by the camera manufacturer for processing the images.

The point is that in terms of image quality and processing flexibility the DNG and proprietary RAW capture options are quite similar, with a handful of nuanced decisions that can be made based on the specific needs and preferences of each photographer.

Today’s Question: Is it possible to export a picture [from Lightroom] along with an XMP sidecar file, on demand, such as when I need to send a picture to a magazine?

Tim’s Quick Answer: If your photo is a proprietary RAW capture you can export a copy of the original capture file along with an XMP sidecar file that contains most of the metadata for the image (as well as Lightroom adjustment settings from the Develop module). However, it is probably best to use a different format (such as TIFF or JPEG) for this purpose, so that the adjustments you’ve applied will be included as part of the pixel values. You can also choose which metadata to include within that exported copy of your master image.

More Detail: When you export a photo from Lightroom you have the choice of which file format to use for the resulting file. You also have some choices related to which metadata you’d like to include in the resulting image. And of course there are other settings to choose from as part of the Export process.

As a general rule I recommend using a TIFF (or JPEG) image when exporting a copy of a photo for publication in some form, depending of course on the specific requirements of the output process being used for the photos. Among other things, that will ensure that you are providing an image file that has all of your adjustments applied to it, and the metadata you’d like to include saved within that image file.

If you send a copy of the original RAW capture, along with the XMP sidecar file, then you are depending on the recipient of those files to have Lightroom (or Adobe Camera Raw) in order to view or process your image with your adjustments applied to it. If for any reason you ever need to use this approach, you can simply choose the “Original” from the Image Format popup in the File Settings section of the Export dialog. An XMP file will be created along with a copy of the original RAW capture as part of the export process.

If you choose an option other than “Original”, such as “TIFF” or “JPEG”, then an XMP file will not be created as part of the process. Instead, any applicable metadata will be stored within the image file that is created as part of this export process. You can choose from several options using the Include popup in the Metadata section of the Export dialog. For example, if you want to minimize the amount of metadata information included within the image file you might choose the “Copyright & Contact Info Only” option from this popup.

The key is to understand what type of file is best suited for your particular needs. For the example of a magazine submission mentioned in today’s question, a TIFF or JPEG file will generally be preferred. But when sending files to others for any purpose it is always important to understand their specific requirements, taking into account what you’re comfortable sharing in terms of file types, overall image size, and metadata details.

Today’s Question: You recommended only using a very fast hard drive if you are going to store your Lightroom catalog on an external drive. But how do you determine if a particular hard drive is fast?

Tim’s Quick Answer: You want to ignore the maximum theoretical speed you might see in the promotional materials for a given hard drive, and instead try to determine the sustained data transfer rate the drive is actually capable of, the maximum speed of the interface used to connect the drive to your computer, and the speed capabilities of your computer with regard to a connected hard drive. In general I would suggest choosing an SSD (solid state drive) device that connects with the fastest data connection available on your computer.

More Detail: Unfortunately, it isn’t generally very easy to determine the actually data transfer speed capabilities of a hard drive. The best solution (which isn’t very practical) would be to perform actual data transfer tests on a wide range of hard drives. However, such tests aren’t widely performed and published in a way that would make it easy to choose a particular drive.

In some cases, the speed rating I see on packaging and in advertisements for hard drives reflects the theoretical maximum speed of the interface connecting the drive to the computer. In the case of USB 3.0, for example, you might see an indication that the drive supports up to 600 MB per second, when in fact a more realistic expectation for an external hard drive connected via USB 3.0 would be on the order of 100 to 200 MB per second.

This misleading advertising is (thankfully) not as common as it used to be. Instead most hard drive manufacturers seem to be simply leaving sustained transfer rates out of the specifications, and instead only telling you that the drive supports, for example, USB 3.0. To me this is just a clever way of leading you to believe that the drive will transfer data as fast as USB 3.0 will allow, which isn’t true in most cases.

When you can find an indication of the sustained data transfer speed (such as through online tests and reviews), that can be very helpful information. Otherwise I would opt for an SSD (solid state drive) storage device over a “traditional” hard drive with spinning platters, and I would opt for the fastest data connection you are able to use with your computer. With a traditional hard drive there is also a general correlation between the speed at which the platters spin (such as 5400 or 7200 rpm), so when you have the choice I would opt for the faster rotational speed.

But ultimately, even with the same specifications, a variety of different hard drives will be capable of transferring data at different rates. You can help tip the odds in your favor by opting for the fastest connection your computer supports and opting for an SSD drive. But whenever possible it is best to see actual performance testing results so you have a better sense of the performance you can expect.

Today’s Question: In response to the question about moving a Lightroom catalog, is it a bad idea to keep the catalog on an external hard drive so it can be moved among different computers more easily?

Tim’s Quick Answer: Putting your Lightroom catalog on an external hard drive provides a perfectly good solution for accessing your catalog from different computers. However, you’ll want to keep in mind that this approach can also significantly degrade overall performance in Lightroom.

More Detail: Lightroom tends to make extensive use of the Lightroom catalog, depending on your level of activity within Lightroom. Therefore, the overall performance for your computer when it comes to actually accessing the catalog files can have a tremendous impact on overall performance within Lightroom.

As a result, I generally recommend keeping your Lightroom catalog on a fast internal hard drive within your computer, to help maximize overall performance in Lightroom. In many cases (though there are certainly exceptions) an external hard drive will have considerably slower performance than an internal hard drive. In turn, that means that having your Lightroom catalog on an external hard drive can seriously degrade performance within Lightroom.

Storing your Lightroom catalog on an external hard drive can certainly be convenient in terms of being able to then access the catalog on different computers simply by moving the hard drive between those computers. However, because performance can be degraded significantly by this approach, I recommend only using this approach when doing so will provide a clear advantage to your workflow.

If you only need to access your Lightroom catalog on a different computer on a periodic basis, it might be better to copy the catalog each time you need to switch computers. But of course for some photographers it will be worth dealing with degraded performance in Lightroom in order to provide the convenience of accessing the catalog via a removable hard drive.

If you do decide to store your Lightroom catalog on an external hard drive, I highly recommend investing in a fast drive that makes use of a high-speed data connection to your computer.

Today’s Question: How do I transfer my catalog from one computer to another?

Tim’s Quick Answer: To move a Lightroom catalog from one computer to another, I recommend copying the entire folder that contains your Lightroom catalog to the new location. Then rename (or move) the original folder to clearly identify it as a backup copy, so you don’t inadvertently open what is out an outdated copy of your catalog.

More Detail: The Lightroom catalog actually consists of several individual files, which are all stored within a single folder location. So the first step here is to identify the folder location for your catalog. To do so, within Lightroom choose “Catalog Settings” from the Edit menu on the Windows version of Lightroom or from the Lightroom menu on the Macintosh version. In the Catalog Settings dialog you can click the “Show” button to the far right of the Location label on the General tab. This will open a window in your operating system showing the location of the folder that contains your Lightroom catalog, with that folder highlighted.

Next, close Lightroom so the catalog will be closed and the temporary files within the catalog folder will be deleted. Then copy the folder that contains your Lightroom catalog to the new location. I then recommend renaming (or moving) the original folder that contained your Lightroom catalog in order to avoid confusion. From this point forward you want to be sure to only open your Lightroom catalog in the new location.

The first time you want to open the Lightroom catalog from the new location, you can navigate to that location within your operating system. Then double-click the file with the “lrcat” filename extension, which is the actual Lightroom catalog file. This will cause Lightroom to launch automatically and open the catalog. You should also confirm that on the General tab of the Preferences dialog in Lightroom that the Default Catalog setting is set to “Load most recent catalog” (or to the specific catalog you want Lightroom to open every time you launch it).

Provided your photos remain in the same location, when you open the catalog from the new location all of your photos will be referenced and available in their original storage location. In other words, moving the catalog to a different location does not create any problems referencing the photos in their existing location.

Today’s Question: Perhaps this is an odd question for which there isn’t really an answer, but do you have any thoughts on how big or small I should display the thumbnails for my photos when browsing them?

Tim’s Quick Answer: There are two basic size settings I recommend for browsing thumbnails of your photos. When you are browsing in search of a photo you’re familiar with, I recommend using the smallest thumbnail size you are comfortable with. When browsing to find a photo you’re not so familiar with (or when you aren’t sure exactly what you’re looking for) I recommend using a relatively large thumbnail size.

More Detail: I think the key thing here, which is part of the reason I wanted to address this question, is to remember that most software for browsing thumbnails of your photos enables you to resize the thumbnails. In other words, instead of just accepting the default thumbnail size, adjust the size to suit the specific task you’re performing.

When you are seeking a photo you’re familiar with, you’ll likely be able to identify the image even with a very small thumbnail size. In this type of situation you may have already applied a filter to the images as well, which will further help you identify an image even with a small thumbnail. In this type of situation I prefer to use thumbnails that are as small as is reasonable. In other words, don’t make the thumbnails so small that you’re not comfortable browsing your photos. For each photographer the ideal thumbnail size for this scenario will be different.

When you’re browsing among photos you aren’t quite as familiar with, or that you otherwise can’t easily identify from a small thumbnail, then I think it makes sense to use as large a thumbnail size as you are comfortable with. This will increase the amount of scrolling you’ll need to do as you browse among the photos, but it will make it that much faster and easier to actually locate a particular image.

I also highly recommend hiding all unnecessary software interface elements (such as the panels in Lightroom or Adobe Bridge) while you are browsing among thumbnails. Doing so provides more space for the actual thumbnails, and helps minimize visual distractions that might get in your way.

Today’s Question: Sometimes, especially when working on graphic elements in a photo composition, I use the Pencil tool instead of the Brush tool to add or cleanup small areas. When I increase the brush size for the Pencil tool a little bit, the brush shape becomes more of a cross instead of a square, and then it starts to turn into a jagged circle. Is there a way to force the Pencil tool to have a square brush shape when I enlarge it?

Tim’s Quick Answer: The solution here is to use a brush with a square shape rather than a round shape. That will enable you to have a square shape for the Pencil tool at any brush size.

More Detail: The Pencil tool is really just a variation on the Brush tool but with a brush that always has a hard edge to it. The behavior described in today’s question really relates to the fact that the current brush is round, but without a soft transition at the edge. This created the jagged appearance due to the lack of anti-aliasing for the circular shape created with square pixels.

You can, however, employ a square brush. Photoshop even includes a set of square brushes you can use. Start by choosing the Pencil tool, and then click on the brush popup toward the far left of the Options bar (just to the right of the popup for the tool presets). On the brush popup that appears, click on the gear icon at the top-right of the popup. Then choose Square Brushes from the popup. I recommend choosing the “Append” option in the dialog that appears, so that the additional brushes will be added to the existing set, rather than replacing them.

You can then choose one of the square brush shapes that will be available now on the brush popup on the Options bar. Then, when you resize the brush (using the left and right square bracket keys: [ and ]) the brush shape will still be perfectly square, just at a different size.

Note, by the way, that you can get the same behavior as the Pencil tool by using the Brush tool instead, and setting the Hardness value to the brush to 100%.

Today’s Question: I see that you were on an extended trip involving photography in a variety of different locations over the course of multiple weeks. How do you go about making sure that you actually review all of your photos along the way, so that you end up identifying all of your favorites from the trip without missing any important photos?

Tim’s Quick Answer: In general I simply make a point of reviewing all of my photos as part of the overall process of downloading and backing up those photos. However, in some cases I will take an extra step to identify photos that haven’t been reviewed yet, to help make sure I don’t miss any photos in my overall review workflow.

More Detail: To be sure, when I’m traveling on an extended trip, it can be a challenge to keep up with my workflow. In my mind the most important tasks are to download my photos and create an additional backup, so that I know my photos are safe. Secondarily, I try to make sure to review all of my photos as I go, to ensure I don’t miss any images in my review along the way.

That generally means that at the end of each day I download my photos, perform a backup of all of the new photos, and then review all of the new captures in order to identify my favorites. In most cases this is feasible, but on some trips I am simply too busy (or too tired) to complete this review each day.

When I’m not able to keep up with my image review during a given trip, I will add an additional step to my workflow to help make sure I actually review all of my photos. This involves adding an attribute to all images that I have actually reviewed, so I can see at a glance if there are any photos that have not yet been reviewed.

In my case I use Lightroom to manage my photos. I use star ratings as my primary attribute for identifying favorite photos, but I also use color labels for some secondary purposes, such as to mark photos I want to be sure to share with others.

For me that leaves the “pick” and “reject” flags in Lightroom as an attribute I don’t generally use. Therefore, I can use a “pick” flag to identify images I have already reviewed, so that any images without that flag still require review.

This may sound like it adds a bit of complexity, but it is actually quite simple. First, I always sort my photos by capture time when I am reviewing photos, and I actually review my photos in the order they were captured. That means when I’m done reviewing photos for the time being, even if there are more photos left to review, all photos up to and including the current photo have been reviewed.

Therefore, whenever I’m finished reviewing photos in this type of scenario, the last photo I reviewed will be selected. I can then scroll up to the very first photo in that folder, and hold the Shift key while clicking on the thumbnail for that photo. This will select all photos that have already been reviewed. In the case of Lightroom I can then make sure I’m in the Grid view (by pressing “G” on the keyboard) so I can update multiple photos at once, and then I assign a “pick” flag to all of the selected photos by pressing “P” on the keyboard.

In this way, when I’m finished reviewing photos, all photos that have been reviewed will have a “pick” flag, and my favorites will have a star rating assigned. Any images that don’t have a “pick” flag (such as newly imported photos) are the ones I know I still need to review.

Today’s Question: I have tried some ideas I had for naming folders for my family photo archive. I tried family names. The vast majority of my images have three main attributes. The most common attribute my images contain is people. I expect to be able to provide names for 90% of the people in the images. Another attribute is the place the photo was taken. I estimate I will know location taken for around 50% of the images. Finally, every image was taken on a specific date. In most cases, I’m only interested in the year. I estimate I can provide this date for around 50% of the images. I’m wondering if it’s worth my time to categorize images into folders at all. Why not just put all the images into one folder? If I’m very diligent about populating all pertinent metadata fields and adding keywords, won’t that be the means to locate most desired subsets of images using search?

Tim’s Quick Answer: If the total number of photos is somewhat reasonable (perhaps under around 10,000 images), I would be perfectly comfortable with using a single folder for all of these family photos, depending upon metadata values to locate specific images. If the number of photos is relatively large, I recommend using at least a basic folder structure based on the estimated year for each photo.

More Detail: This question is a great example of the fact that there are many workflow scenarios that might call for a solution that is different from what I normally recommend.

In this case the issue at hand is the folder structure for storing images. In general I recommend using at least a basic folder structure to provide a basic form of organization at the file system level. This ensures you have some degree of organization that goes beyond any specific software you might be using to manage your photos.

Today’s question, however, provides a good example of a scenario where a folder structure may be difficult to implement, and may actually get in the way of organizing specific photos. In that case it may be perfectly reasonable to use a single folder to contain all of the photos being managed for this purpose.

Before deciding to avoid the use of folders altogether, I would spend at least a little time evaluating whether some degree of folder structure might be helpful. In the context of family photos it can be particularly challenging to define an appropriate folder structure. For example, you might initially assume that a folder structure based on generations would work. However, this approach can be problematic for images that contain family members from multiple generations, which is probably quite common within any family photo library.

First and foremost, I recommend giving some thought to how you will think about photos when you are looking for specific images, as well as what approach you might want to take when simply browsing your overall photo library.

For family photos I think it is reasonable to take a completely different approach to folder structure than you might otherwise use for other categories of photographic images. That could include a single folder for all images, or a date-based structure by year (or even decade), for example.

The key is to step back and think about what options might make sense for defining an overall organizational structure that goes beyond metadata values (such as keywords) you might add for the photos. In this case I think some form of date-based folder structure probably makes the most sense, but there are certainly other options that might make sense as well.

Today’s Question: How accurate are the colors on a typical camera LCD panel?  Is there a way to readily calibrate the LCD similar to the way that a computer monitor is calibrated?

Tim’s Quick Answer: Camera LCD displays are reasonably accurate, but not perfect. Unfortunately there is not a way to truly calibrate and profile a camera’s LCD display. In general you are only able to refine the overall brightness (and in some cases contrast) of the display. In most cases you will have few (if any) options for adjusting the color accuracy of the display.

More Detail: As a general rule, I recommend that you not depend on the actual image preview on your camera’s LCD display as an accurate indication of the overall tone or color in your photos. For overall exposure I recommend employing the histogram display. For color, your best option is to capture in RAW (rather than JPEG) so you are better able to refine the color in your photos without risking any degradation of image quality.

Obviously it would be helpful if you could use the LCD display on your camera to accurately evaluate all aspects of the images you capture. Unfortunately that really isn’t the case.

When it comes to color fidelity, I have actually found that in most cases the camera’s LCD display provides a reasonably accurate (and in some cases highly accurate) view of the colors in your photos. Fortunately, if you are capturing in RAW this isn’t a serious concern. For video captures or photos captured in the JPEG format, inaccurate color can be more of a challenge. But again, in most cases the color is reasonably accurate on the LCD display, to the extent that you would know if there was a serious problem with the color of your captures.

Tonal values are a more significant concern in most cases. To begin with, the ambient lighting conditions can have a more dramatic impact on your perception of tonal values in a preview image as compared to color values. Also, the brightness (and possibly contrast) adjustments for the LCD display can have a tremendous impact on your perception of overall tonal values in the images you view on the LCD display.

As a result, I highly recommend that you employ the histogram display on your camera to evaluate overall exposure. When it comes to color, it is generally best to treat the LCD display as a general preview that will be reasonably (but not completely) accurate in terms of the fidelity of colors.

And hopefully one of these days we’ll have the ability to calibrate camera LCD displays much as we can calibrate and profile our the monitor displays on our computers.