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.

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.

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.

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.

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.

Is Bridge Needed?


Today’s Question: I have learned how to use Lightroom from your courses. When I look at other tutorials I see the instructor using Bridge (it seems like everyone uses Bridge except me). It appears to me that if I use Lightroom like you taught me I don’t really need Bridge. Is this correct? Which one has the advantage over the other?

Tim’s Quick Answer: In my opinion, once you’ve started using Lightroom to manage your photos, it is best to avoid the use of Adobe Bridge for browsing your photos. Using Bridge introduces the potential for making changes to the metadata for your photos in Bridge, causing that metadata to be out of sync with the metadata contained within your Lightroom catalog.

More Detail: To be sure, if you are careful not to update any of the metadata for your photos within Adobe Bridge, it is perfectly fine to browse photos using Bridge if you find that to be more convenient. However, in general I recommend that you consistently use Lightroom as the exclusive image-management tool once you start using Lightroom to manage your photos.

I suspect if you see other instructors using Adobe Bridge, it may be for illustrative purposes, or convenience when showing specific techniques in Photoshop. For example, in some cases when I am teaching Photoshop techniques I will create a folder of working photos that I will use to demonstrate the techniques. In that type of situation it is simpler to use Adobe Bridge to browse the photos, and then double-click on a photo to open the image in Photoshop. But for my “real” workflow of managing, optimizing, and sharing my photos, everything is initiated from within Lightroom.

Bridge and Lightroom are a bit different in terms of overall architecture, making it difficult to compare the two without considering the context of your workflow. But in general I recommend Lightroom as a more efficient tool for image management, in large part because of the efficiencies gained by having a central catalog. That said, there isn’t a single right answer for all photographers. It is important to consider your overall workflow when choosing specific software. But once you’ve chosen software for managing your photos, I consider it beneficial to use that software consistently as the core component of your workflow.

Workflow for Plug-Ins


Today’s Question: I often use Nik filters (especially Silver Efex Pro for black-and-white). I can apply them from within Lightroom (via “Edit In”) or I can first send the picture to Photoshop and apply the filters there and then bring the work back into Lightroom. Is one way better than the other?

Tim’s Quick Answer: In terms of the net result for your photos, there is really no difference between these two approaches. However, my personal preference is to send the image to Photoshop and apply the filters from there, primarily to provide greater flexibility in case I decide to apply more than one filter to a given photo.

More Detail: Whether you send a photo directly to the plug-in software from Lightroom or first send the image to Photoshop, the result will be a derivative image, typically in the TIFF file format (though sometimes PSD or JPEG format).

The reason I prefer to use Photoshop is that this approach provides greater flexibility in the event I choose to apply more than one filter to an image. If you want to use two different filters from Lightroom, you would create two derivative images in the process. So, for example, if you create a black and white interpretation of a photo using Silver Efex Pro, you would then have a TIFF image based on your original capture.

If you then decide you want to apply some additional effects using, for example, Analox Efex Pro, you might send the black and white TIFF image from Lightroom to Analog Efex Pro. In the process, an additional TIFF image would be created. The result would include your original capture plus one TIFF for the black and white version of the photo and another TIFF for the version that includes the Analog Efex Pro filter effect.

By sending the image to Photoshop first, you will only have a single derivative image, even if you make use of multiple filter plug-ins. You could create each effect as a separate layer in the TIFF (or PSD) image, so that you’re preserving all of the effects individually but without creating multiple derivative files.

If you tend to only apply a single filter effect using a single plug-in, there’s really no reason to use one approach or the other. Whichever approach you feel is easiest and provides the best flexibility for your particular workflow is perfectly fine. That said, as noted above I do prefer to include Photoshop as part of this workflow in order to provide greater overall flexibility in my workflow.

JPEG Quality


Today’s Question: If I understand correctly, the Quality slider in the Export module of Lightroom is the primary controller of file image size. I wonder if you could explain the Quality slider in more detail and what is an ideal image file size (kb) range for optimizing web images in terms of preserving image quality and page load speed across various devices.

Tim’s Quick Answer: The Quality setting for JPEG images relates to the degree of compression applied, which in turn impacts the size of the JPEG image file. A higher setting for Quality results in a larger file size, and a lower setting for Quality results in a smaller file size. For online sharing or other situations where you want to strike a balance between file size and image quality, I recommend a Quality setting of 80% in Lightroom, or a value of “8” (eight) in Photoshop or other applications.

More Detail: Because of the nature of JPEG image compression, it is difficult to predict exactly how large the final file will be. Images with greater detail will generally not compress as well, and thus will have a larger file size when saved as a JPEG file. Images with less detail (more areas that have minimal texture and many pixels of the same or similar color) will have a smaller file size when saved as a JPEG.

JPEG compression essentially involves simplifying the information in the image being saved. Generally speaking this process involves dividing a photo into blocks of sixteen by sixteen pixels (256 pixels per block) and then simplifying the information within those blocks. At a lower the Quality setting, the simplification process will be more aggressive. With more simplification of the image data, the file size is smaller.

One way to think of this is with an illustrative analogy. Imagine that one block within a photo contains only blue pixels. Specifically, every single pixel in that block is exactly the same shade of “sky blue”. Instead of having to repeat “sky blue” as a pixel color for all of the 256 pixels in that block, the information can be saved to the file as “256 sky blue pixels”. Again, this is an over-simplification of what’s actually happening, but it gives you a sense of the process.

This process of simplifying the information within a JPEG using blocks of pixels is a key reason that a low Quality setting results in lower image quality. With stronger compression, there is greater simplification of the information within the image, and the grid structure of the 256-pixel blocks can become visible in the image.

Thus, there is an inverse relationship between file size and image quality. At a higher Quality setting the file size will be larger, but the quality will be greater with less risk of compression artifacts. As noted above, it is difficult to predict the final file size with great precision. Instead, I recommend making your decision based on a determination of the importance of image quality relative to file size.

I recommend using a Quality setting of 80% in Lightroom (8 in other applications) when file size is a key concern. When image quality is the highest priority, I recommend saving in a file format such as TIFF without any destructive compression, or using the highest value for Quality if you need to use a JPEG format to control the final file size.

High Pass Sharpening


Today’s Question: What are the situations when “High Pass Sharpening” [in Photoshop] might be a good choice over “Smart Sharpen” or other methods?

Tim’s Quick Answer: The technique known as “High Pass sharpening” is a technique I consider to be more about emphasizing texture and detail in a photo, rather than sharpening to compensate for softness in a photo. Thus, I would recommend the High Pass technique when you are focused on enhancing detail and contrast in a photo. Note that the technique produces an effect that is very similar to that provided by the Clarity slider in Adobe Camera Raw and Lightroom, among other software.

More Detail: The High Pass sharpening technique gets its name from the High Pass filter in Photoshop. Using the High Pass technique enhances midtone contrast in an image, helping to emphasize detail. If you’re familiar with the basic concepts behind sharpening in most imaging software, you can think of the High Pass technique as being similar to sharpening, but with a higher effective Radius setting.

In other words, like sharpening, the High Pass technique enhances contrast along existing contrast edges in a photo, but it does so across a larger area. In other words, the contrast being enhanced along edges in a photo spreads out from those edges more than would otherwise be the case with typical sharpening.

In fact, with the Unsharp Mask filter in Photoshop you can achieve a result very similar to High Pass sharpening. Simply set a high value for the Radius setting (around 20 pixels or so) and a relatively low value for Amount (around 20% to 50%). And, as noted above, similar results can be achieved with the Clarity slider in Lightroom and Adobe Camera Raw, as well as the newer Dehaze slider in these two software applications.

For those unfamiliar, the High Pass technique is relatively easy to accomplish in Photoshop. Start by creating a copy of the Background image layer, which can be done by dragging the thumbnail for the Background layer to the “Create a New Layer” button (the blank sheet of paper icon) at the bottom of the Layers panel. Then set the Opacity to 50% for this layer, using the control at the top of the Layers panel. Change the blend mode from the default of “Normal” to “Overlay” using the popup at the top-left of the Layers panel. Then choose Filter > Other > High Pass from the menu, and set the Radius value to around 10 pixels, adjusting to taste. Click OK to apply the filter, and then fine-tune the Opacity setting for the Background Copy layer.

Delete Catalog After Upgrade?


Today’s Question: I just upgraded from Lightroom 5.7 to Lightroom CC. In the process, it appears that my catalog was copied, upgraded and renamed from Photos1 to Photos1-2, so now I have two catalogs. Is there any reason to save the Photos1 catalog or can I safely delete it?

Tim’s Quick Answer: Provided the new catalog is working properly, there is no reason to retain the older version of your catalog other than as a “worst case scenario” backup. So once you’re confident the new catalog is in good shape and you have backed up the new catalog, you can delete the old catalog.

More Detail: When you upgrade to a new “major” release of Lightroom, your existing catalog needs to be upgraded as well, so that the catalog reflects the new features and options available in the new version of Lightroom. As part of that process, your new version of Lightroom will create a new catalog that is essentially an upgrade to your existing catalog. In other words, your previous catalog will remain as it is, and a new catalog will be created that contains all of the information from your existing catalog.

While this is a good approach in terms of being cautious, it does mean that you may end up with several “extra” catalogs, by virtue of having catalogs from older versions of Lightroom. As far as I’m concerned, once you’re confident that your new catalog is in proper working order and you’ve backed up the new catalog, there is no real benefit to retaining old copies of catalogs from older versions of Lightroom.