## Partial Pixels

Today’s Question: While I was watching one of your video lessons that covered sharpening in Photoshop, it struck me that you were using a value of less than one pixel to define the sharpening effect. How can a sharpening filter work on partial pixels?! Shouldn’t the value for the size (Radius) only be in whole numbers?

Tim’s Answer: I think the way I would describe this (understandable) source of confusion is that the number of pixels for the Radius setting is really a shorthand of sorts that goes beyond a simple number of pixels. In other words, you aren’t really having an effect that goes down to a level smaller than a single pixel, as that’s not possible with pixel-based editing. Instead, you are having an effect that is tapered across multiple pixels.

So, when you set the Radius to a value of a half pixel, you aren’t really having an effect on half of a pixel at a contrast edge, but rather are using a value of 0.5 as part of the (somewhat complex) formula that determines how much contrast is enhanced along existing contrast edges within the photo.

Keep in mind that the size of the sharpening effect (often referred to with a “Radius” value) interacts with the strength of the sharpening effect (often referred to with an “Amount” value). In addition, with many sharpening filters there are additional values you can adjust or factors that are used to determine exactly how the contrast enhancement of sharpening is applied to various areas throughout the image.

So, the Radius setting really relates to the size of the transition area for the contrast being enhanced. In some cases, with a very strong sharpening effect, the formula will cause a change with values that suggest granularity of one-tenth of a pixel. That’s not because the pixels are being divided into smaller units (they aren’t), but rather because the formula is blending the effect into the image. So in some ways you can think of the Radius setting as defining the degree of transition for the effect.

To get a sense of this, you can create a simple graphic in Photoshop. For example, create an image that is half black and half white, with a hard transition from black to white. Then apply a very slight blur to the image, so that there is a transition from black to white that spans perhaps ten pixels in the image. Then choose Filter > Sharpen > Unsharp Mask from the menu to bring up the dialog for the Unsharp Mask dialog (I recommend this filter for the test because it is a simpler sharpening filter than Smart Sharpen). Set the Amount to 500% (the maximum value) and the Threshold to 0 (the minimum value), and evaluate the effect in the image as you adjust the value for Radius.

If you conduct this little experiment, you’ll see that even a change of 0.1 or 0.2 pixels for Radius will have an impact on the sharpening effect in the photo, with higher values causing the gradation in the image to become smaller than they appear with a lower value for Radius. Again, this is just part of the complexity of the formula in play for this (and other) sharpening filters.

## Filtering for No Keywords

Today’s Question: I have a Lightroom question. I’m trying to either sort or find files that have no keywords in either a folder or collection. I know the symbol in the bottom right of the thumbnail but there’s no way to sort with that. Any suggestions?

Tim’s Answer: There is actually a very easy way to filter images to show only those that don’t have any keywords assigned to them. The icon you refer to is a “badge” indicating that keywords are assigned to a given image. While there isn’t exactly a filter based on the absence of that badge, there is a filter for “No Keywords”.

You can navigate to a specific folder containing the images you want to filter, of course. Then you want to view the Library Filter Bar, which can be enabled by choosing View > Show Filter Bar from the menu if it isn’t already visible. You can also use the backslash key (\) to toggle the display of the Library Filter Bar.

Next, to clear any existing filters, click the “None” option. Then click the “Metadata” option to display a set of columns that allow you to filter your images based on a variety of metadata values. Make sure all of the columns are set to the “All” option initially, so the images are not being filtered. Then click the header for the right-most column, and choose “Keyword” from the popup.

This will present a list of the keywords that have been assigned to any of the images that are currently available (in other words, the images in the folder you’re currently browsing). You will also find a “None” option on the list. Click that option, and the images will be filtered to include only those without any keywords assigned.

You could, of course, combine a variety of different filters in addition to the lack of keywords, in order to further refine the range of photos being displayed. But as you can see, it is quite simple to filter a set of photos in Lightroom to include only those without keywords assigned to them.

## Camera Connection

Today’s Question: Why do you remove the card from the camera when downloading photos as opposed to leaving the card in the camera, connecting the camera to the computer and downloading and deleting the photos without ever touching the card?

The second reason is the “real” reason for my personal decision to never connect my camera to the computer for downloading. Put simply, I’m afraid I’ll end up knocking my camera onto the floor. I’ve been accused of being a little clumsy at times, and I’m pretty sure I would end up snagging the cable connecting the camera to the computer, sending the camera flying off the table to the floor.

I’ve heard photographers express concern about damaging their camera by repeatedly removing and inserting media cards, and this is certainly a valid concern. I have seen more than one camera with bent pins caused by a CompactFlash card that didn’t get inserted quite right, for example. But with proper care I don’t consider this to be a significant concern. At least for me personally, I think the bigger risk involves knocking the camera off the table.

So, that’s my reasoning. But ultimately I would say that there isn’t an especially strong argument either way, unless downloading as quickly as possible is the highest priority for you. If speed is critical, I recommend using the fastest cards and the fastest card reader available, instead of downloading directly from the camera. But otherwise, as far as I’m concerned this is really a matter of personal preference.

## Pixel Grid

Today’s Question: When I zoom in really close on a photo in Photoshop, I can see grid lines outlining every pixel. I find this very distracting. Is there a way to turn it off?

Tim’s Answer: The grid lines you are referring to are the “Pixel Grid” display option in Photoshop, which is enabled by default. I too find those grid lines to be rather distracting, and most of the time I prefer not to see them. So, I keep the Pixel Grid turned off, and turn it on temporarily when I feel it will be helpful.

You can disable (or enable) the Pixel Grid display in Photoshop by choosing View > Show > Pixel Grid from the menu. When a checkmark icon is shown to the left of Pixel Grid on the menu, that is an indication the feature is enabled. When you turn the Pixel Grid off, the checkmark icon will disappear along with the grid display you’ve been seeing when you zoom in on your photos.

## Dye Sub Printers

Today’s Question: What, if any, are the downsides to owning a nice dye sub printer for professional output? I wonder why nobody talks about these printers. From my experience they are “picture perfect” and would be hard pressed to see any difference between a dye sub print or a film print (not digital) but I wonder about the ink-jet vs dye sub as well. What am I missing? Even my local Wal-Mart uses dye sub printers for their “professional” output.

Tim’s Answer: As with just about any comparison between two categories of products, when it comes to evaluating dye sublimation (or “dye sub” for short) printers there are both advantages and disadvantages. In my opinion, it is entirely plausible that dye sublimation printers could have originally become the most popular way for photographers to print their images, but instead photographers favored photo inkjet printers.

Let’s first consider some of the advantages of dye sub printers.

Dye sub printers get their name from the process of sublimating solid dye into a gaseous form and impregnating that dye into the surface of the paper being printed to. This produces several significant benefits.

Dye sub prints are truly continuous tone, rather than being made up of a series of tiny “dots” as is the case for photo inkjet printers. That results in smoother transitions of tone and color, and higher perceived quality. Of course, recent inkjet printers are capable of producing such tiny ink droplets that they can be thought of as being virtually continuous tone, but that wasn’t the case with earlier inkjet printers.

Because of the way solid dyes are sublimated into the surface of the paper, dye sub prints are also generally more durable than photo inkjet printers. For example, the prints from dye sub printers are better able to withstand being exposed to water, almost to the point that you could consider a dye sub print to be “waterproof”.

Of course, there are some disadvantages to dye sub printers as well, and I believe these are the primary reasons these printers did not become more popular with photographers early on in the history of photo printers. It should be noted that it is altogether possible that if dye sub printers had been more popular early on, they would have also been more profitable and therefore manufacturers might have invested money to improve upon these shortcomings.

Dye sub printers are generally slower compared to most photo inkjet printers, although some of the top-end dye sub printers will perform on par with many inkjet printers.

Dye sub printers are more limited in size, with the ink ribbon cartridges being matched to the paper size. In general you can think of a dye sub printer as only supporting a single print size. Thus, dye sub can be a great option for producing a large number of 4×6 photo prints, but not a good solution for photographers who need to print at a wide variety of sizes.

Dye sub printers also tend to be more expensive than photo inkjet printers in terms of overall operation. This, again, is probably mostly due to the very large market for photo inkjet printers compared to the smaller market for dye sublimation printers.

As you may have gathered by now, the limitations of dye sublimation printers relate more to a lack of flexibility, which is probably the primary reason that photo inkjet printers gained much higher adoption rates than dye sublimation printers. That said, dye sub printers are still an excellent choice for certain applications. If a dye sub printer suits your specific needs, I would certainly not hesitate to make use of such a printer. That said, you may very well find that a good photo inkjet printer will also be able to meet your specific needs, with additional flexibility as a bonus.

## Recover Deleted Photos

Today’s Question: In yesterday’s question you mention being able to recover data from a formatted memory card. I recently downloaded images to my laptop, formatted the card (in the camera) and experienced a crash before further backup and lost all images. How do I recovery data from a formatted card?

Tim’s Answer: It is actually very easy (with the right software) to recover photos that have been lost due to accidental deletion or formatting of a media card. As I mentioned in yesterday’s email, this recovery is possible because in most cases when you delete photos or format a card the information is not actually removed. Instead, the entry for the file (or files) is simply removed from the “table of contents” for the card, and the space is marked as free. As long as you don’t fill that space with new photos (or other data) you can recover the photos you thought were lost.

There are many software tools available for this purpose. In fact, some card manufacturers include a free recovery utility with some of their media card products. If you don’t have access to a free software tool for data recovery, I highly recommend PhotoRescue from DataRescue (http://www.datarescue.com).

I have found PhotoRescue to consistently be able to recover lost photos, even in situations where the card had become damaged. Even better, you can download a free trial version of PhotoRescue and see a preview of the images it is able to recover, before buying the software to actually recover the images. And the software is able to recover RAW captures in addition to other image types.

The most important thing to keep in mind is that capturing new images will cause the deleted photos to be permanently over-written. So, if you have accidentally deleted images or formatted a card, set that card aside until you can use software such as PhotoRescue to recover the lost images on the card, and you’ll most likely find those photos haven’t been lost after all.

## Memory Card Lifespan

Today’s Question: A question to which I can’t guess the answer: I have a 64 GB memory card. I take the images, download them into Lightroom, then I put the memory card back in my camera and format the card. How many times can I format the card before it is time to use a new card?

Tim’s Answer: I suppose part of the reason you’ve not been able to find a clear answer to this question is that there isn’t an entirely clear answer to begin with. But that doesn’t mean I can’t provide at least some basic guidance that will (hopefully) prove helpful.

There are a few things worth understanding here.

First, since the question specifically relates to formatting the card, we’ll start there. With most cameras the act of formatting a digital media card has a very minimal impact on the life of the card. The reason for this is that in most cases formatting the card doesn’t actually do very much.

Yes, I realize that when you format a digital media card in your camera, all of the photos disappear. But in actual fact, with most cameras the images are not truly erased, but rather the “table of contents” for the card is updated to indicate there are no files on the card. This is why it is possible to recover “lost” photos from a card, as long as the photos that were deleted (or erased by formatting) have not been over-written by new photos (or other data).

So, formatting the card has a very minimal impact on the life of the card.

Next, it is important to understand that the lifespan of a flash memory storage device (which is the category most digital media cards fall under) is limited based on an approximate number of read/write operations. You can essentially think of the individual storage components on the card as being something that wears out, although that’s a significant over-simplification of what’s going on.

The expected lifespan of a given card depends upon the specific components used for that card, and can vary wildly from one manufacturer or product line to the next. Some cards are estimated to be able to handle around 100,000 read/write operations for each “unit” of storage space, while others might have a life expectancy on the order of perhaps one million read/write operations. And, of course, it is important to keep in mind that these expectations are presented as a median expectation, so your results could of course vary considerably.

Finally, we have to take into account that today’s media cards are “intelligent” about how the storage is used. This includes, for example, a form of “load balancing” where the card will vary where each new file is stored so that each individual unit of memory will have about the same amount of use as every other unit of memory on the card. Also, as parts of the card start to go bad, those areas are automatically taken out of service. This helps prevent data loss or corruption, and also explains why you might see the amount of available space on an empty card go down over time.

Putting all of these (and other) factors together, you can probably appreciate how difficult it can be to predict with any degree of accuracy just how long a given digital media card will last before it can’t be used. In my experience, for most high-quality cards, you are more likely to replace the card for a faster or higher-capacity card before the card actually fails. But, of course, some cards fail almost immediately, some cards cause data corruption, and some cards last much longer than you would ever expect.

Having said all that, you can use the information above to calculate some basic estimates of potential lifespan based on how many photos you tend to capture on a given card over an extended period of time.

## Density in a Photo

Today’s Question: A couple of days ago you gave the following example to a question about opacity of layers:

“…a quick way to increase density in an image is to add an adjustment layer without actually making any changes to the default settings for the adjustment layer. Then change the blend mode for the adjustment layer to Multiply”.

I’ve been wondering what you mean by “increasing the density” of an image. That terminology never comes up when discussing processing with Lightroom. What would the equivalent treatment be if working solely in Lightroom?

Tim’s Answer: In large part I would say that my use of the term “density” in the context quoted above is a product of having started my photographic adventures in the world of film photography (and specifically, slide film photography). With a slide, there is a need to ensure an adequate degree of density in the information captured in the emulsion. In other words, a completely clear slide (with no density) has no useful information, while a properly exposed slide has “good” density. This relates, in the context of slide film, to the density of the dyes present in the slide film, which form the actual image you can see.

When I refer to density in a photographic image, I’m referring to the same basic concept in terms of information being present in the photo. In other words, in a very basic way I’m talking about darkening the exposure to increase the density of information, as long as we think about that information in terms of adding darkness. In other words, the term density in this context makes more sense when thinking of a photo printed on paper rather than an image projected on a computer display.

Lightroom does not include blend modes, and so you can’t use the “trick” of using the Multiply blend mode to darken the exposure (increase density) or the Screen blend mode to brighten exposure (reduce density). However, you can achieve a reasonably similar result through the use of the basic tonal adjustments.

I would start with the Exposure slider to apply a basic overall adjustment to the tonality in the photo. You can also fine-tune the effect with the Shadows and Highlights sliders to adjust the overall appearance of detail in the image. You can even make use of the Whites and Blacks sliders as needed to fine-tune the brightest and darkest values in the photo.

Ultimately, besides illustrating the potential pitfalls of applying terms from film photography to digital photo processing, I think this topic underscores the importance of understanding your tools and focusing on the photo. In other words, there are many different tools available in many different software applications, and I wouldn’t get too caught up about trying to translate the tools from one application into another. Instead, I encourage you to focus on the photo you are working on, think about what will make that photo look its best, and then use the tools in the software you’ve chosen to work toward that result.

## Image Processor

Today’s Question: Is there any way to convert a folder (not an individual file) of TIFF images to JPEG without loss of the TIFF images, with Photoshop CS6?

Tim’s Answer: There most certainly is a way to process multiple images (including TIFF files, among other image file formats) into JPEG images using Photoshop CS6 (or later), and it called “Image Processor”.

I prefer to initiate the process from Adobe Bridge, because I find it to be easier to locate and select the specific images I want to process from within Adobe Bridge. If you take this approach, you can select the images you want to process, and then go to the menu and choose Tools > Photoshop > Image Processor. The selected images will automatically be set as the source images for processing.

If you prefer to start from within Photoshop, you can initiate the Image Processor by choosing File > Scripts > Image Processor from the menu. If you have already opened the images you want to process, you can choose the “Use Open Images” option at the top of the Image Processor dialog. You can also process a folder full of images by choosing the “Select Folder” option, then clicking the button to actually select the source photo. Again, by using Adobe Bridge you can select specific images within a folder for processing.

The next option allows you to specify the location where you want the resulting images saved. If you use the “Save in Same Location” option the images will actually be saved in a sub-folder of the source folder, with a name based on the file type being created (such as “JPEG”). You can also select an entirely different folder as the destination of the image files being created.

In the File Type section you can specify the type of files to be created, choosing among JPEG, PSD, and TIFF options. Note that you can select multiple file types if desired, and that you can adjust individual settings for each file type. So, in this case you could turn on the “Save as JPEG” checkbox, for example. You can also enable the option to resize the resulting images (and of course enter specific pixel dimensions you want the images to fit within). There is also an option to convert the images to the sRGB color space.

When you have all of the settings established, you can click the Run button and the images will be processed. Note that the source images will not be modified in any way. Those source images will simply be used as the basis of the processing to create additional copies of the photos.

## Black and White Workflow

Today’s Question: I do a significant amount of my work in Black and White. Would I work in color until ready for printing….or should I change to B&W first thing?
Or perhaps you would suggest a special sequence of operations best suited for B&W optimization?

Tim’s Answer: In large part the approach I recommend depends on the degree to which you are certain that you want to convert a given image to black and white. In other words, I would first want to know whether you thought a given photo would ever be presented in color at all.

If you’re not sure, of if you want to have a color version of the photo in addition to a black and white version, I recommend applying at least the basic adjustments to the image before working in black and white. This would include basic color correction, adjusting overall brightness and contrast, and other basic adjustments. I then might save this version of the image and create a copy (or a Virtual Copy in the context of Lightroom) for the black and white interpretation.

When you move from adjustments for the color image to a black and white interpretation, be sure you revisit the overall tonal adjustments. In particular, check the values established for black and white in the photo, as the overall tonal distribution may have been changed by your conversion to black and white. And, of course, pay attention to other considerations that will be especially important for a black and white image, such as emphasizing (or toning down) texture and detail in the photo.

If I know for sure that I will only work with a photo as a black and white image, I will bypass all but the very basic adjustments to correct for the initial exposure, so that I can move into the black and white processing more quickly.

Of course, it is important to consider the overall approach you take to workflow for your photos. If you are working in Lightroom, there’s no penalty to diving right in to black and white adjustments for a photo, because Lightroom’s Develop module always applies adjustments non-destructively. However, you may at least want to create a Virtual Copy of any color photo you want to process into a black and white version.

If you’re using Photoshop to process your images, I would apply very basic overall adjustments to the initial capture (such as via Adobe Camera Raw), and then use adjustment layers and perhaps some filters or plug-ins on a duplicate of the Background image layer in order to create the black and white interpretation.