Category: Ask Tim Grey

Today’s Question: Can you give tips for those of us that don’t have automatic exposure bracketing on our cameras, for capturing an HDR [high dynamic range] image?

Tim’s Quick Answer: As a general rule, if you don’t have automatic exposure bracketing (AEB) as a feature of your camera, you can set an initial exposure in Manual mode and then adjust the shutter speed by two stops for each subsequent exposure until the full tonal range of the scene has been captured.

More Detail: The key to creating a final HDR image that includes the full range of tonality from the original scene is to capture enough images with varying exposures to cover the full range of tonal values within the scene.

When you are using automatic exposure bracketing, this process is generally quite simple. It can be similarly simply when you need to capture each frame individually, provided you take a consistent approach to this process.

I recommend first capturing an image that is dark enough to retain full detail in the brightest areas of the scene. You can use an automatic or semi-automatic exposure mode to determine the best exposure settings if that is easier for you. Then dial in those same settings in the Manual exposure mode.

After capturing the first image in Manual exposure mode, with settings that preserve highlight detail, you can increase the exposure time (use a longer shutter speed) by two stops for the next capture. For example, if you have your camera set to adjust the exposure in one-half stop increments, you can turn the dial that adjusts shutter speed by four “clicks” to increase the exposure time.

Repeat this process of capturing an image and then adjusting the shutter speed by two stops, until the histogram shows that you have captured an image that retains full detail in the darkest shadow areas. I will often actually capture an image that is even brighter than necessary, in order to help minimize noise in the dark shadow areas of the scene.

With this “manual” approach, and with a little practice, you can quickly and easily capture a sequence of images to create an HDR image, even without the benefit of automatic exposure bracketing.

Today’s Question: Would it be good to minimize capture sharpening, including the sharpening applied by default in Lightroom [or Adobe Camera Raw] until after merging multiple exposures into a high dynamic range [HDR] image?

Tim’s Quick Answer: In general I do recommend that you minimize sharpening for the initial captures that will assembled into an HDR image, although in actual practice this depends on the specific workflow (and software) you’re using to assemble the initial HDR image.

More Detail: In many cases when you assemble an HDR image, each original raw captures is rendered to produce full pixel values for the high dynamic range result. As a result, it can be advantageous to ensure those original captures have minimal adjustments, or at least only adjustments that will be beneficial.

When it comes to sharpening, I prefer not to apply sharpening to the initial captures as part of this process. In other words, I want to combine the pixel values based on the original capture data, and then apply sharpening and other corrective adjustments after the HDR image has been created.

With some software the issue of minimizing initial processing is not actually a factor. For example, if you process several exposures into an HDR image using the “Photo Merge” feature in Lightroom, the resulting image will be an Adobe DNG file with any prior adjustments stored as metadata. In other words, prior adjustments won’t actually harm an HDR image created in this way.

As a perhaps more dramatic example, if you convert the original captures to black and white in Lightroom, and then merge those black and white captures to an HDR image in Lightroom, the HDR image will also be black and white. However, because the adjustments you applied are actually just metadata values, you can switch to the Color setting for the Treatment control in the Basic set of adjustments, and the black and white HDR image will return to the original color from your original captures.

So, as a general concept I recommend minimizing the processing you apply to the raw captures you will merge into an HDR result. However, in some cases this issue is not a concern based on the workflow of certain software (such as Lightroom) when creating the initial HDR image.

Today’s Question: One thing that I wish Lightroom would do is manage variants of files that I work in Photoshop to take advantage of it’s sharpening and editing capabilities. For example, the original Photoshop file might be a TIFF that I create in the ProPhoto RGB color space with the intent of printing it. But then I might want another in the sRGB color space at a lower resolution to enter in a contest. Lightroom would track the first file but the second one, created with Save As, wouldn’t be tracked unless I have Lightroom sync the folder.

What’s the most efficient way to keep the Lightroom catalog current when Save As is required?

Tim’s Quick Answer: This is one of the reasons I strongly recommend not using the “Save As” command when working with an image you have sent to Photoshop from Lightroom. I would either send the source image to Photoshop separately for each derivative image you need to create, or leverage the Export command when that suits your specific needs (such as when creating a JPEG image).

More Detail: When you use the Save As command in Photoshop after sending a source image to Photoshop from Lightroom, in most cases the resulting derivative image file will not be included in your Lightroom catalog. Only the initial derivative saved with the “Save” (not “Save As”) command will be included in your catalog.

There are several ways you could work around this, including the “Synchronize Folder” command available when you right-click on an existing folder within Lightroom.

For images you need (or want) to work on in Photoshop for any reason, I recommend using the “Edit In” command in Lightroom (found on the Photo menu) for each derivative image you want to create. I also generally use the original source image for creating each of these derivatives. So, for example, you could send the original image to Photoshop for the TIFF you want to create for printing, and then use the “Edit In” command a second time to create a JPEG for other purposes.

In many typical scenarios for sharing images, you might also simply use the Export command to create your derivative image, adding the resulting image file into your Lightroom catalog as part of the process. Within the Export dialog you can configure the output settings as needed, such as by choosing the JPEG image file format with the option selected to convert that image to the sRGB color space. You can also then turn on the “Add to This Catalog” checkbox in the Export dialog, so that the derivative image you are creating (and presumably saving in the same folder as the master image) will be added to the Lightroom catalog as part of the export process.

You might also consider simply not saving the derivative images at all in most cases. With very few exceptions, when I am creating output in any form, I will initiate the process with my “master” image. That might be the original capture included in my Lightroom catalog, or it might be a TIFF or PSD image I’ve created using Photoshop. In either case, that “master” image is generally the starting point for any output I want to create. In other words, in most cases I don’t need to retain all of the various derivatives I might create within my workflow, since I will usually start the process of sharing a photo by using the master image file rather than a derivative copy.

Today’s Question: I have a black & white film negative. How do I convert it in Photoshop or Lightroom to print an image?

Tim’s Quick Answer: For a black and white film negative I recommend first scanning the film in color, then converting to black and white and optimizing for the final print.

More Detail: As a general rule it is best to work with a full-color image even when your intent is to produce a black and white final result. That is because the color version of the image will have more information to work with, which in turn can help you produce a final image with greater detail and overall quality.

Of course, with a black and white negative it might seem a little silly to scan the film as a color image, since in concept the film doesn’t contain any color. However, there is generally at least a slight degree of color in the film, even if that is only the “orange mask” that is added to some films. Naturally you will also want to be sure to (in general) scan at the highest optical resolution of the scanner being used to scan the film, and save the image as a TIFF or PSD (not a JPEG) to preserve overall image quality.

Once you have scanned the film, you can optimize the resulting image to prepare it to be printed. In the context of Photoshop that would likely mean first adding a Black & White adjustment layer, and in Lightroom you could choose the “Black & White” option for the Treatment setting in the Basic section of adjustments. You’ll also of course want to optimize the overall image in overall tonality, detail, texture, and sharpness.

For the final print, you may also need to compensate for the capabilities of your printer. Many printers, for example, aren’t able to render full detail in the dark shadow areas. You can compensate by lightening up the value for the black point and darken down the value for the white point. This is something that would generally involve a degree of testing of your printer, so you know how much of a compensation to apply to produce a print with maximum detail.

It is also worth noting that in general you will want to use a custom printer profile, or custom software settings for your printer, to help ensure that the print is actually perfectly neutral. In many (or most) cases you will be using all of the ink colors in your printer to produce a black and white print, and it can sometimes be a challenge to produce a print that is perfectly neutral with only shades of gray, and without any hint of color cast.

Today’s Question: You’ve said a variety of things about the Adobe DNG [digital negative] file format, some good and some bad. But what I really want to know is, all things considered, should I convert my raw captures to DNG?

Tim’s Quick Answer: In a word, no. Taking all of the various factors into account, my personal preference (and general recommendation) would be to retain the original raw captures from your camera, and to not convert those original captures to the Adobe DNG format.

More Detail: Let me say right from the start that there are absolutely some great benefits to the use of the Adobe DNG file format compared to proprietary raw capture formats. I’m not suggesting that converting raw captures to DNG is somehow “bad”. I simply feel that on balance I’d rather retain the original raw capture format rather than converting those files to DNG and deleting the original captures. And I also don’t feel it makes a lot of sense to both convert to DNG and still retain your original raw captures.

One of the key reasons I prefer to retain the original raw captures is that they represent the original capture with no modification whatsoever. While the Adobe DNG format retains the pixel data from your original capture, there are some “private” metadata from the camera that may be lost. That information would generally relate to unique features of a specific camera model, which would require software from the camera manufacturer to fully leverage.

I also prefer to keep metadata updates separate from the original capture data. In the context of a raw capture that means, for example, having metadata updates written to an XMP “sidecar” so that the original capture file remains undisturbed. This can also help to streamline a backup workflow.

One of the primary motivations for using the Adobe DNG format is to avoid a proprietary file format that is not openly documented the way the DNG format is documented. In addition, DNG files are generally around 20% smaller than the original raw capture, with no loss of image quality or detail. So there are indeed advantages to the Adobe DNG file format, to the extent that if your camera supports capture directly to DNG, you may want to make use of that option.

But in the context of a workflow that might involve discarding the original raw capture file after converting to the Adobe DNG format, my preference is to simply retain the original capture files.

Today’s Question: How can I copy just a portion of the pixels in an image to a new layer in Photoshop, so I can then move those pixels into another area of the image?

Tim’s Quick Answer: You can duplicate selected pixels from an image layer in Photoshop by selecting the pixels you want to duplicate, making sure the applicable layer is active on the Layers panel, and then choosing Layer > New > Layer Via Copy from the menu.

More Detail: Duplicating selected pixels can be very helpful for creating a composite image that combines duplicated elements from the same image, for performing image cleanup work to hide a blemish, or for a variety of different purposes.

The first step is to select the pixels you want to duplicate. In general I recommend selecting an area larger than the actual pixels you want to duplicate, both to make it easier to create the selection and so you have a bit of flexibility in how you blend the duplicated pixels into the surrounding area. For example, you could simply use the Lasso tool to create a selection that is a little larger than the area of pixels you actually want to duplicate.

After creating the selection you can choose Layer > New > Layer Via Copy (or hold the Ctrl/Command key on the keyboard while pressing the letter “J”) to duplicate the selected pixels to a new layer.

At this point you can add a layer mask to the new layer containing the duplicated pixels, so that you can hide the pixels on the outer edge of the area you selected in order to provide better blending for those pixels. Click the “Add Layer Mask” button (the circle inside a rectangle icon) at the bottom of the Layers panel to add a layer mask. Then paint with black to hide pixels from this image layer and white to reveal pixels that had been hidden.

You can also use the Move tool to move the pixels around to the desired area, and of course use the various Transform commands to resize or reshape this layer as well.

Today’s Question: I’ve been using the Quick Collection [in Lightroom] when I want to work with certain images. Sometimes I want to then put those same images into a new collection. Is there an easier way to do that? I’ve been making a new collection and then dragging and dropping the images to that new collection, which is a little cumbersome.

Tim’s Quick Answer: You can actually save the images in the Quick Collection into a new collection by simply right-clicking on the Quick Collection and choosing Save Quick Collection from the popup menu.

More Detail: As the name implies, the Quick Collection in Lightroom is really intended for quickly grouping images together, generally for a temporary purpose. If you want to retain a grouping of images for a longer period of time, a “normal” collection is often preferred.

Fortunately, in those situations it is very easy to “convert” the Quick Collection to a normal collection. Simply right-click on the Quick Collection in the Catalog section of the left panel in the Library module, and then choose “Save Quick Collection” from the popup menu. You’ll then be able to specify the name for the new collection and choose whether you want to remove the images from the Quick Collection as part of this process.

Obviously you can choose a name that is most meaningful to you based on the images you’ve included in the Quick Collection. I do recommend clearing the Quick Collection as part of this process, so the Quick Collection will then be ready to use for a future project.

The new collection you created as part of this process can then be found in the Collections section of the left panel, with the name you used when you saved the Quick Collection as a “normal” collection.

If you already have access to the “Lightroom Quick Tips” course on GreyLearning, (such as via the GreyLearning Ultimate Bundle) you can see today’s answer in action by watching episode 10 of the course here:

https://www.greylearning.com/courses/lightroom-tips

Today’s Question: I’m still using Photoshop CS6 because I did not want the subscription option [Photoshop CC]. Raw files for my Canon 5D Mk III are 27MB in size, but become 24MB when I convert to Adobe DNG [Digital Negative]. Am I doing something wrong? Is the raw file still the same? Or am I losing critical data on conversion?

Tim’s Quick Answer: The smaller file sizes you’re seeing are due to the fact that the Adobe DNG file format employs lossless compression to reduce the file size. None of the original capture data is altered as part of this process, other than any “special” metadata that might only be supported by software from the camera manufacturer.

More Detail: As a general rule you can expect a raw capture converted to an Adobe DNG file to have a file size that is about 20% smaller than the original capture file. As noted above, this is due to lossless compression that will not alter the original capture data for the image. You will not lose any image quality or detail as part of the conversion to Adobe DNG.

It is worth noting, however, that any “special features” that might be supported by the software from your camera manufacturer would be lost as part of this conversion process.

For example, recent models of Canon cameras include a “dual pixel” feature that can only be leveraged through the use of Canon’s software with the original raw capture. Similarly, most recent Nikon camera models support an “Active D-Lighting” feature that requires Nikon software (and the original capture format) to make use of.

Other than these “special” features (that are not supported by Adobe Lightroom, Adobe Camera Raw, or Photoshop, for example), there is no impact on your original captures caused by the conversion to the Adobe DNG format. In particular, the smaller file size caused by lossless compression for the DNG file need not be of any concern either, as it is actually one of the benefits of the DNG format.

Today’s Question: Adobe Bridge seems to only show me the photos that appear in a given folder. Is there a way to see all types of files that are in those folders instead of only the photos?

Tim’s Quick Answer: Yes, you can view all files within the folder you are currently browsing in Adobe Bridge by choosing View > Show Hidden Files from the menu.

More Detail: By default, Adobe Bridge only displays files that are saved in supported file formats. To the photographer that often means only image files, such as your RAW captures, Photoshop PSD files, TIFF images, JPEG images, and other supported image formats.

However, Adobe Bridge also supports a wide variety of other file types, including audio and video file formats, for example, as well as a variety of document formats (such as Adobe PDF files).

Adobe Bridge will not, by default, display non-supported file types, which in some cases may be inconvenient. If you want to browse all files of both supported and non-supported file types within Adobe Bridge, you can turn on the “Show Hidden Files” option.

Keep in mind that enabling the “Show Hidden Files” option may create considerable clutter when you are browsing your files. For example, if you process your proprietary raw captures using Adobe Camera Raw, an XMP “sidecar” file will be created containing the metadata related to the adjustments you applied within Adobe Camera Raw. The XMP files are hidden by default in Adobe Bridge, because there is generally no need for a photographer to interact directly with those files.

When you enable the “Show Hidden Files” option, you may very well see an XMP sidecar file for every single raw capture within the current folder, which could translate into seeing two files for every image in that folder.

So, while it can certainly be useful in certain situations to be able to view hidden files in Adobe Bridge, the clutter caused by this option can be a bit distracting. I therefore recommend that if you need to enable the “Show Hidden Files” option that you only keep it turned on for as long as you actually need to browse non-supported file types in Adobe Bridge, and then turn the setting off again.

Today’s Question: I often photograph simple textures during my travels, and sometimes those textures seem like they will go well with another photo. I can’t figure out though how to just put the texture on the image. Do I need to create a selection? That doesn’t seem like it would be very easy or effective.

Tim’s Quick Answer: You can easily add a texture from one image onto another image by first layering the two images into a single document in Photoshop, with the texture layer on top. Then change the blend mode for the texture layer, most likely to the Overlay blend mode, using the popup at the top of the Layers panel. You can also adjust the Opacity for that layer to taste.

More Detail: When creating a composite image in Photoshop you will generally employ a layer mask (often using a selection as a starting point for that layer mask) in order to hide and reveal specific areas of the upper image layer, therefore revealing a portion of the underlying image layer.

When you want to combine a texture from one image into another image, this approach generally won’t provide the intended result (at least not without considerable work). Instead, you will want to blend the two (or more) layers together through the use of a blend mode. The result is similar to what could otherwise be accomplished with a multiple exposure image.

The default blend mode on the popup at the top of the Layers panel is “Normal”, which causes no blending at all. Instead, the upper layer will block all layers below, unless a layer mask is used to block some of the upper layer in order to reveal portions of the lower layer.

To employ a blend mode for this purpose, you’ll first want to combine two (or more) images into a layered document in Photoshop. Then make sure that the texture layer is at the top of the stack on the Layers panel, dragging the thumbnail for that layer to on the Layers panel reposition it if necessary. Be sure the texture layer is active by clicking on the thumbnail for that layer on the Layers panel, so that changes you make will affect the texture layer.

With a blend mode you can essentially combine multiple layers into a seamless result. In most cases you will likely find that the Overlay blend mode provides a good result, because it is one of the contrast blend modes. Light areas of your texture layer will lighten the underlying image, and dark areas of the texture layer will darken the underlying image. You could also experiment with other blend modes to find the effect you like.

Once you’ve selected a blend mode, you can adjust the Opacity setting at the top-right of the Layers panel as needed. This will reduce the appearance of the texture in the image, so that it provides a more subtle addition to the overall composition.