Image Processing

Today’s Question: It’s clear to me that when I shoot a JPEG in camera the JPEG image is created from the RAW capture with the camera’s internal “formula”.  But what “formula” is being used with either the Image Processor in Photoshop or in the Save Image approach in Adobe Camera Raw? And can that formula be adjusted?

Tim’s Quick Answer: The “formula” used to create a JPEG image from a RAW capture when using Adobe Camera Raw, Photoshop, or Lightroom is essentially the “Adobe Camera Raw” formula. And yes, you can most certainly adjust that formula at least in terms of refining the settings for RAW processing for the photo before creating the JPEG image.

More Detail: I think one of the things that photographers don’t always realize about a RAW capture is that there isn’t a single “correct” method for processing that RAW capture. Obviously there is a degree of artistic interpretation the photographer can apply, but in addition different software will interpret the same RAW capture in different ways.

Thus, the software you’re using to process RAW captures will generally produce a different (and sometimes very different) result compared to the preview you see on the camera’s LCD display. The underlying software algorithms are different from one RAW processor to the next, the available controls may be different, and of course you may apply the various adjustments in different ways.

When a RAW capture is processed in Lightroom or Photoshop, the underlying “engine” for processing that RAW capture is Adobe Camera Raw. Thus, the result you will see when you create a derivative image (such as a JPEG file) based on a RAW capture will depend upon the underlying settings for Adobe Camera Raw. That may translate into the adjustments you’ve applied in the Develop module in Lightroom, the settings you’ve applied in Adobe Camera Raw, or simply the default settings if you haven’t actually modified the adjustments for the image yet.

You can adjust the settings by first applying adjustments in Lightroom or in Adobe Camera Raw, though you obviously can’t change the underlying algorithms within these applications. But by applying adjustments in Lightroom or Adobe Camera Raw before creating a derivative image using Lightroom, Adobe Bridge, or Photoshop, the derivative image you create as part of that process will reflect the adjustments you applied to the original RAW capture.

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Image Corruption

Today’s Question: I have attached an image file with color bars at the lower right hand corner. I was wondering if you have seen this before and can identify the source of the problem. I have experienced this probably about three times over the last 6 months. I have a Canon 5D MKIII camera and used my Tokina 16-28mm f2.8 lens for this shot. Is my camera sensor starting to go bad, lens problem, bad memory card, etc.? Any help is appreciated.

Tim’s Quick Answer: The image provided by the photographer who submitted this question demonstrates the classic symptoms of a corrupted capture. This type of issue is generally caused by a problem when the file is written to the card, or when the file is copied to your computer. Thus, the key is to isolate the specific cause of the issue.

More Detail: Identifying the source of file corruption for a digital capture can be a little bit of a challenge, with some misleading information along the way. For example, an uncorrupted image displayed on the camera’s LCD does not necessarily indicate that the image file isn’t corrupted, because what you’re seeing is the JPEG image rendered by the camera, not the actual RAW capture.

It is possible that the source of this problem is the camera itself, the card being used to store the photos, the card reader you are using to download the photos, any of the cables used to connect the camera or card reader, or the computer itself, among other possible causes.

As soon as this sort of issue starts to show up, it is important to try to isolate the problem as quickly as possible. This involves keeping track of what equipment is in use when the problem occurs, and trying to isolate the specific source. So, for example, you can test different cards, different card readers, and possibly even different cameras to try to identify the cause.

Once this sort of issue arises I’m not comfortable trusting the components involved. To be sure, it is possible that the corruption was created by ejecting a card from the camera before the file had been completely written. But if you’re confident that wasn’t an issue, there is likely a hardware problem at play. I would tend to stop using any card that exhibits this sort of corruption. But again, the key is to test out different hardware to isolate the specific source of corruption. This can be a time-consuming process, especially if the problem only occurs sporadically. But in most cases if the problem is not a matter of user error it is caused by hardware problems, so you’ll want to find the source as quickly as possible so you can capture new images with confidence.

You can learn more about the issue of corrupted captures in my article titled (appropriately enough) “Corrupted Captures” that appeared in the April 2015 issue of Pixology magazine. If you’re not already a subscriber you can sign up at, and I would be happy to send you the back issues at no additional cost.

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Reverting Lightroom

Today’s Question: I updated Lightroom CC yesterday and now I have a complete mess on my hands. The software doesn’t run. It opens for a second or two then crashes. I have restarted, shut down, reinstalled the software, and still nothing. Any thoughts on where to go next?

Tim’s Quick Answer: If you’re able to get to the Preferences dialog, I would try turning off the “Use Graphics Processor” checkbox on the Performance tab. I have also received a report that turning off the “Show ‘Add Photos’ Screen” checkbox on the General tab of the Preferences dialog has helped prevent crashes. If you’re not able to get there or turning off this option doesn’t resolve your issue, I would suggest uninstalling the latest update and then downloading and installing the initial Lightroom 6 release as an initial step in reverting to an earlier update.

More Detail: I have received more than a few emails from readers who are having difficulty with the latest update to Lightroom (version CC 2015.2 or 6.2). These users are reporting frequent crashes. I am using the latest update, and am not experiencing any problems myself, but clearly the latest update has created some problems for a number of users.

I’ve found that in general disabling the “Use Graphics Processor” option can be helpful for those experiencing crashes with Lightroom. This option is found on the Performance tab in the Preferences dialog, which can be accessed by choosing Lightroom > Preferences from the menu on the Macintosh version of Lightroom or Edit > Preferences on the Windows version of Lightroom.

As noted above, I’ve also received reports that turning off the “Show ‘Add Photos’ Screen” checkbox on the General tab of the Preferences dialog has helped resolve issues with Lightroom crashing. So I would certainly recommend turning that option off if you are having issues with the latest Lightroom update.

If turning off checkboxes doesn’t provide a solution (or you’re not able to get to this option), you may want to revert to an older version of Lightroom. Start by uninstalling Lightroom 6/CC. Then download the original Lightroom 6 version from this page on the Adobe website:

You can then install the original Lightroom 6/CC release, using your Adobe ID to sign in during the installation process to validate your CC version of Lightroom. I would then suggest waiting for another update beyond the 2015.2 (or 6.2) release of Lightroom. Hopefully that update will be arriving very soon, and will resolve the crash issues that some users are reporting.

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Metadata for Derivative Images

Today’s Question: I follow your suggestions where my “master” file is a Photoshop PSD file and I make JPEG images from the master files. Is there a way in Lightroom or Bridge to “mark” a photo (flag, color, stars, etc.) and have that information stay in the metadata of the exported image?

Tim’s Quick Answer: You can most certainly add metadata to the “master” image, and have that information included in any derivative images you create. This is the default behavior when using, for example, the Image Processor from within Adobe Bridge. When exporting from Lightroom you can also enable the option to retain metadata for the exported images.

More Detail: If you’re using Adobe Bridge to create JPEG images from your “master” photos, I recommend the Image Processor utility as the most convenient option for creating derivative JPEG images. Simply select the photos you want to process, then choose Tools > Photoshop > Image Processor. You can specify the settings to be used and then process your photos to create JPEG derivative images that will include the metadata from the source photo.

The same option is available when exporting photos from Lightroom. Simply select the photos you want to process and click the Export button at the bottom of the left panel in the Library module to initiate the process. Use the various options available to specify how you want your derivative images to be created. In this case, the key setting is the “Include” popup in the Metadata section of the Export dialog. In this case you would probably want to use the “All Metadata” option so that all of the metadata from the source images will be included in the derivative images being created.

Keep in mind that only “standard” metadata can be included with this process. That means that Pick (or Reject) flags added in Lightroom will not be included in the derivative image. However, star ratings, color labels, and other standard metadata can be included in the exported images files, as long as the appropriate option for metadata is selected in the Export dialog.

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Image Protection

Today’s Question: Can you give us suggestions on copyrights, image size, watermarking, etc. when posting images to Facebook? In other words, how do we protect our images from being used (or used effectively) without our permission?

Tim’s Quick Answer: In my mind there are three basic approaches when it comes to the notion of protecting your photos from theft when sharing your images online. First, you can mark the photos with a watermark that makes them let useful to a would-be image thief. Second, you can keep the image size small enough that it can’t really be used for any significant purpose. Or third (my preferred approach) you can choose not to worry about image theft too much, on the assumption that sharing your photos represents (hopefully!) greater value than the negative consequences associated with the theft of your photos.

More Detail: From my perspective, there is really no such thing as completely protecting your photos from theft that still preserves what I would consider to be a good user experience in terms of enjoying your photos. So we’re mostly talking about compromise here.

In general I prefer not to include a visible watermark on a photo, except for situations where I feel that watermark may be advantageous as a promotional tool. For example, in some cases I might include my website address as a watermark on the image. In this case, I try to make the watermark as unobtrusive as possible, while still being visible enough to provide some promotional value.

I do generally try to keep photos I share online at a reasonably small size. Doing so can minimize the risk of photos being stolen for purposes of printing. For example, an image that is resized to about 1000 pixels on the long side can only really be printed at a size of about 3-inches by about 5-inches while retaining good quality for close examination. Keep in mind, however, that when you post an image online, it can most certainly be used in other digital forms at the same size. A photo resized to “only” 1000 pixels on the long side could very easily be used in a typical slideshow presentation, for example, or included in a high-definition (HD) video.

While there are a handful of methods available for protecting photos you share online, most of those methods are either not especially effective or create what I consider to be a less-than-ideal viewing experience for those interested in your photos.

So, again, my approach is to try to keep in mind that sharing photos online will (hopefully!) provide promotional value for me as a photographer (or as a photographic educator). My intent when sharing photos online (beyond simply enjoying the process of sharing) is for the promotional benefit of sharing exceed whatever harm may come from having my photos stolen.

I fully realize that for many photographers image theft is a very real concern. However, I think it is important to realize that generally speaking if you share your photos online they are never completely safe from theft. So, I recommend using a modest watermark, keeping image sizes relatively small, and trying not to worry too much about the risks of online theft.

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Partial Pixels?

Today’s Question: Zooming all the way in [in Photoshop], you can see each individual pixel. But I’m able to place a guide at different locations within a pixel. How can this be? You can’t cut within a pixel, can you? Shouldn’t the Guide snap to the boundary of that pixel?

Tim’s Quick Answer: It is indeed possible to place a guide in a position that does not align with the edge of the pixels in your image, which I agree is a bit unusual at least in the context of a raster (pixel based) image. However, it is possible to have your guides “snap” to the edges of pixels in an image.

More Detail: For those not familiar, Guides in Photoshop allow you to position non-printing horizontal or vertical lines within an image. Those Guides can then be used to align objects, force objects to snap to a specific position, keep track of margins or borders in an image, and more.

There are several steps required in order to force new guides you create on an image to snap to the edge of the pixels in the image. The first is to make sure the “snap” behavior is enabled. To do so, you can confirm that there is a checkmark icon to the left of the Snap item on the View menu in Photoshop. If there isn’t a checkbox shown to the left of “Snap”, that indicates the feature is disabled, and you can select Snap from the View menu to turn this feature on.

Next, you need to make sure that the unit of measure for the Rulers feature is set to Pixels. If you haven’t already displayed the Rulers for the image, you can choose View > Rulers from the menu to turn on the Rulers display. You can also press Ctrl+R on Windows or Command+R on Macintosh to toggle the Rulers display. Then right-click on one of the Rulers (at the top or left edge of the image) and choose Pixels from the popup menu that appears. Note that you can also change the unit of measure for the Rulers on the “Units & Rulers” page of the Preferences dialog.

With these two options set, you will be able to create a new Guide that snaps to the edge of the pixels within the image. A Guide can be created by simply clicking on one of the Rulers and dragging into the image. To force that Guide to snap to the edge of pixels, hold the Shift key while dragging the mouse to the position where you want the Guide created. The new Guide will then “snap” to a pixel boundary as long as you’re holding the Shift key when you release the mouse to place the Guide.

So, in concept all you need to do to snap a guide to the pixel boundary is hold the Shift key while dragging from a Ruler to create a Guide. However, you also need to be sure the Snap option is enabled, and that the unit of measure for the Rulers is set to Pixels.

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Dodge and Burn Variability

Today’s Question: Evidence seems to suggest that the dodge & burn tools (in PS CS6) affect only the blacks, not all of the colors in the region painted. Is this true? If not what explains this apparent behavior? Regardless are there any tools that work the same way that dodging and burning does in a wet darkroom; i.e., affecting all of the colors?

Tim’s Quick Answer: The Dodge and Burn tools in Photoshop do indeed have an impact on colors, not just shades of gray. The key thing to understand is that the Dodge and Burn tools focus on specific tonal ranges, with options for Shadows, Midtones, and Highlights. You can, however, use a technique that employs the Overlay blend mode for the Brush tool to ensure more consistent results when dodging and burning in a photo.

More Detail: When using the Dodge and Burn tools in Photoshop, the results can certainly be a little misleading. When you paint across a photo with either of these tools, it may appear that colored areas are getting less effect (or even no effect) compared to shades of gray within the photo. But the difference relates to luminance values rather than color values. Very often, for example, if you are using the Midtones option for the Dodge or Burn tool, areas with relatively strong color saturation will actually be brighter than a midtone value, and thus are not impacted as much as the gray areas that do fall into the midtone range.

I prefer to use a technique that provides a bit more consistency across the photo, and also enables me to more easily switch between dodging (lightening areas of a photo) and burning (darkening areas of a photo).

The first step is to create a new image layer that has specific properties. Start by clicking on the thumbnail for the top-most image layer on the Layers panel, which may very well simply be the Background image layer. Then hold the Alt key on Windows or the Option key on Macintosh, and click the “Create a New Layer” button (the blank sheet of paper icon) at the bottom of the layers panel. Because you were holding the Alt or Option key on the keyboard, the New Layer dialog will appear.

In the New Layer dialog you can enter a name for the new layer, such as “Dodge and Burn”. Then change the blend mode to Overlay using the Mode popup. Finally, turn on the “Fill with Overlay-neutral color (50% Gray)” checkbox. Having this option turned on will make it easier to evaluate your paint strokes later if that ever becomes necessary. Click OK to create the new layer.

Next, choose the Brush tool from the toolbox, and press the letter “D” on the keyboard to set the colors to their default values of black (as the foreground color) and white (as the background color). On the Options bar, set the Opacity setting for the Brush tool to a value of around 10% to 20%.

You can now paint with black to darken areas of the photo and paint with white to brighten areas of the photo. The painting will appear on the new layer you created, and will affect the image based on the Opacity setting. If you paint over the same area more than once (releasing the mouse button between brush strokes) you can build up a stronger effect. To switch between painting with black versus white (for darkening versus lightening) simply press the “X” key on the keyboard.

With this technique you can exercise a little more control over the dodging and burning you want to apply to a photo, while getting more consistent results across the photo.

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Lens Profiles

Today’s Question: I’m using a lens for which there isn’t a profile available under Lens Corrections in Lightroom (or Adobe Camera Raw). Is there a way to obtain or create profiles for lenses that aren’t supported by Adobe?

Tim’s Quick Answer: It is possible to build your own custom lens profiles, but quite frankly you might find it easier to simply apply the Lens Correction adjustments manually, and perhaps even create a preset as a starting point for a specific lens for which a profile is not available.

More Detail: Adobe provides the free “Lens Profile Creator” software, which you can use to create profiles for your own lenses. The process involves photographing a series of photos of a target image with the specific camera and lens combination you want to profile, and then using the software to generate a profile based on those captures.

If you would like to learn more about the Adobe Lens Profile Creator, you can find links to a User Guide and downloads for the software for both Macintosh and Windows under the heading “Adobe Lens Profile Creator” about halfway down the Adobe Digital Negative (DNG) information page here:

The profiles used by Adobe Camera Raw and Lightroom correct automatically for geometric distortion, chromatic aberration, and vignetting. All of these attributes can be corrected manually using the various controls in the Lens Corrections set of adjustments. And because the behavior of a given lens is relatively consistent, you could even create a preset that provides a good starting point for your corrections.

To create a preset in Lightroom, for example, you can start by applying the adjustments for a sample image captured with the lens for which you don’t have a profile. Apply all of the various adjustments found in the Lens Corrections section, and when you’re happy with the results for the image click the plus symbol (+) to the right of the Presets section on the left panel in the Develop module.

To ensure the preset you’re creating will only apply the Lens Corrections adjustments to images you apply the preset to, click the Check None button and then turn on the checkbox for Lens Corrections, making sure that all of the individual checkboxes you want enabled are turned on below Lens Corrections. Then type a name for the preset that reflects the lens the corrections apply to, and click Create to create the preset.

This preset can then be applied to other images in order to add the same Lens Corrections settings to other images captured with the same lens configuration.

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Camera Raw Filter

Today’s Question: Once a RAW file has been interpreted as pixels and is open in Photoshop, won’t it be degraded if the Camera Raw filter is applied to these pixels?

Tim’s Quick Answer: It would be fair to say that a direct adjustment using the Camera Raw filter in Photoshop after converting a RAW capture would represent a “destructive” adjustment, by virtue of altering actual pixel values. That said, in some cases this approach provides a helpful solution to an issue with a photo.

More Detail: If you are working with a RAW capture, it is generally best to apply most of your adjustments during the initial RAW processing (such as in Adobe Camera Raw) in order to maximize the benefits of the original RAW data. But it can also be helpful to make use of the Camera Raw filter after the capture. While adjustments that affect pixel values directly can be fairly referred to as “destructive” in terms of altering those pixel values, that doesn’t make those adjustments automatically “bad”.

I generally prefer to take a non-destructive approach to optimizing my photos. I use Lightroom (or Adobe Camera Raw) to process my initial RAW captures, and when I want to apply further adjustments in Photoshop I will use an adjustment layer if that is an option for the type of adjustment I want to apply.

For adjustments that involve the direct manipulation of pixel values, such as using the image cleanup tools in Photoshop, I prefer to use an image layer separate from the underlying Background image layer in order to maximize the flexibility of my workflow.

In this way, it is possible to use the Camera Raw filter in a more flexible way than simply adjusting pixel values directly. You could, for example, create a copy of your Background image layer and apply the Camera Raw filter to that duplicate layer. You could also convert the image layer to a Smart Object by choosing the “Convert for Smart Filters” command on the Filter menu. This will cause any filters (including the Camera Raw filter) to be applied as a Smart Filter, so that you are effectively using the filter as something of an adjustment layer. In other words, the pixel values aren’t being altered directly, and you can return to your adjustments at any time.

For adjustments such as noise reduction, chromatic aberration removal, or perspective correction, it isn’t critical to work with the original RAW capture. Thus, if you neglected to apply these types of adjustments during the initial RAW capture, it is perfectly fine to apply them later in your workflow using the Camera Raw filter. Again, my preference would be to include those adjustments as part of the initial workflow of processing my RAW capture, but if I neglected to apply certain adjustments it is often easier to use the Camera Raw filter than to return to the original capture again. And with many adjustments, the difference in image quality between processing the RAW capture with Adobe Camera Raw and processing the image with the Camera Raw filter will be minimal.

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Bracketing a Panorama

Today’s Question: Is it possible to combine bracketing and a panorama? If so what is the process?

Tim’s Quick Answer: Yes, indeed! You can use automatic (or manual) exposure bracketing for each frame of your composite panorama. Then, when assembling the composite panorama you can either choose which set of exposures to assemble into the final image, or create a high dynamic range (HDR) panorama by assembling the bracketed shots and then creating the final panorama.

More Detail: The specific approach you use for bracketing the individual exposures will vary based on the dynamic range of the scene you’re photographing, your intent for the final image, the capabilities of your camera, and other factors. In general, however, I recommend using the automatic exposure bracketing (AEB) feature of your camera to capture multiple exposures at different exposure settings for each frame of the composite panorama.

So, for example, you might start with the left-most frame in your intended composite panorama, capturing perhaps three bracketed exposures for that frame. For an HDR image I generally bracket by two-stop increments, but you can use one-stop increments if you prefer. Once you’ve captured the set of exposures for the first frame, rotate the camera to the next frame, overlapping by about 20% or so (more for focal lengths below about 100mm). Capture all of the frames of the panorama, using the same exposure bracketing for each.

When you are ready to assemble the final image, if you will create an HDR result, I recommend assembling each of the individual frames as an HDR image, and then assembling all of the HDR frames into the final panorama. Obviously the specifics of the approach here will depend upon the software you prefer to use for both HDR assembly and panorama assembly. The key is to use the exact same settings for the HDR tone-mapping, so that all of the HDR frames in your panorama will blend together seamlessly.

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