Category: Ask Tim Grey

Today’s Question: I often use PNG files in compositing images, because they allow for transparent pixels. Are they like JPEGs in that every time you open, modify, then save the file, you lose image quality?

Tim’s Quick Answer: No, PNG (Portable Network Graphics) images do not have the same quality loss that can be a factor with JPEG images, because the PNG format supports lossless image compression to reduce file size. When you save a normal JPEG image, the compression applied always results in some loss of quality due to the type of compression used.

More Detail: The compression used for JPEG images is “lossy” compression, meaning some information is lost in the process of reducing the file size for a JPEG image. JPEG compression operates by simplifying the information within pixel grids (generally 16 by 16 pixels to a block). That compression causes a change in some pixel values, and can also result in artifacts such as a slight grid texture reflecting the grid used for compression.

Because the compression for a JPEG image is re-applied every time the file is saved, if there have been changes to the pixel values for the image it is possible to have a cumulative degradation effect for JPEG images that are repeatedly altered and saved. Simply opening a JPEG and re-saving it will not cause any further degradation, because the same algorithm would be applied to the same image data, resulting in the same result for the JPEG file.

The PNG file format employs lossless compression, so re-saving the image multiple times (even with changes) will not cause a further degradation of image quality.

I should hasten to add that while PNG images do include support for transparency, they don’t offer the flexibility of an image layer with a layer mask in Photoshop. The transparency of PNG images can most certainly be convenient when assembling images into a composite. However, if you have erased pixels to create that transparency, you can never get those pixels back in the PNG image.

Instead, I prefer to employ a layer mask in the original image, saving that result as a TIFF (Tagged Image File Format) image so that the layer mask is preserved. This approach enables you to employ the effect of transparency for a composite image, while still maintaining the ability to go back and alter which portions of the source image are actually visible versus hidden.

Today’s Question: I see that there is now a version 6.3 update to Lightroom. After the problems many photographers (including me) experienced with the 6.2 update, I’m a little nervous. Do you think it is safe to upgrade?

Tim’s Quick Answer: Based on my testing and feedback from others who have already installed the 6.3 (or 2015.3 for Creative Cloud customers) update for Lightroom, I do recommend installing this update. When you upgrade to version 6.3 (2015.3) update, you will gain access to support for some new RAW capture formats, benefit from a number of bug fixes, and also have the Import process returned (for the most part) to the version from before the major changes that were implemented in the 6.2 update.

More Detail: As I have probably made clear previously, I was not happy with the changes to the Import feature implemented in Lightroom 6.3. Several updated default options were (in my opinion) problematic, some features were removed, and the controls for changing various settings were hidden by default. So I’m happy that the 6.3 update to Lightroom reverts to the previous Import experience.

There had also been a variety of stability problems introduced in the version 6.2 update to Lightroom. While most of those were fixed with a 6.2.1 update, this latest update to version 6.3 includes additional improvements and bug fixes.

As noted above, I have tested the version 6.3 update rather extensively, and have found it to be very stable. I’ve also received feedback from others who have had a similar experience. So, my recommendation is to upgrade to version 6.3 (2015.3) right away. You can do so via the Creative Cloud application (if you are a subscriber), or by choosing Help > Updates from the menu.

Today’s Question: I’m still struggling with the fact that I keep being asked to log in and relicense every time I open the Creative Cloud. Do you know of a solution?

Tim’s Quick Answer: In my experience, there are two solutions (both of which are somewhat related). The first is to simply update to the latest version of the Creative Cloud application. The second is to uninstall and reinstall the Creative Cloud application. In my experience, this has solved the issue of being asked frequently to sign in to your Creative Cloud account.

More Detail: Installing the latest update to the Creative Cloud application is generally very straightforward, and often required to make use of the application. When you pull up the Creative Cloud application you should be asked to upgrade if there is a new version available. If such an update is available, installing it should resolve your issue.

Otherwise, I would recommend uninstalling and reinstalling the Creative Cloud application. You can find the uninstall option in the Adobe Creative Cloud folder within the Program Files folder on Windows, or in the Applications folder on Macintosh.

If neither of these options provide a solution, you can find some more information about possible solutions through the Adobe support website here:

https://helpx.adobe.com/creative-cloud/kb/signed-out-sign-in-required-error-248.html

Today’s Question: I’ve noticed that on Facebook several of my friends (including you) have placed what is essentially a transparent French flag over their pictures. Would you please explain how one would go about doing something like this?

Tim’s Quick Answer: I know that there had been some “automatic” options to update your profile photo in this way, but I opted to create the effect “manually” in Photoshop. I first added an empty image layer above my photo. Then I filled that layer with blue, white, and red in one-third increments, using selections to assist that process. Finally, the Color blend mode was used to cause the color to alter the appearance of the underlying photo.

More Detail: The first step, of course, is to open the photo to which you want to apply the effect. Next, click the “Create a New Layer” button (the blank sheet of paper icon) at the bottom of the Layers panel to add a blank layer.

I used guides to assist with dividing the image into thirds. To take this approach, choose View > New Guide from the menu. Enter “33%” in the Position field, and make sure the Orientation option is set to Vertical. Then click OK to create the new guide. Choose View > New Guide again, enter “66%” in the Position field, and click OK to add a second guide.

With guides added to the image, you can choose the Rectangular Marquee tool from the toolbox and click and drag to create a selection from one corner of the image to the opposite end of the nearest guide. Then choose Edit > Fill from the menu, and choose the “Color” option from the Contents popup to bring up the Color Picker. Select the color you would like to use, and click OK to select the color. Then click OK again to fill the selection with the color.

You can then deselect the active selection by choosing Select > Deselect from the menu. Drag to create the next selection (between the two guides for the second color area, and then from the second guide to the right edge of the photo for the third color area). Use the Fill command for each of the other selections to fill with applicable color for each section.

Finally, set the blend mode for the new layer to Color, using the popup at the top-left of the Layers panel. The solid colors you used to fill the new layer will then be used to alter the underlying color of the image. You can also adjust the Opacity setting for this layer, using the control at the top-right of the Layers panel, to adjust the strength of the final effect.

Today’s Question: How would you rename the images in a single folder when those images come from different cameras and/or are a mix of different file formats? For example, I just came back from a week long trip to Wyoming and captured images using my iPhone and my DSLR in RAW format, JPEG format, and RAW + JPEG formats. That being the case, I have a bunch of different out-of-the-camera file names and various file formats.

Tim’s Quick Answer: My preference is to use the exact same file-renaming strategy for all images within a given folder, regardless of which camera was used or what file types I may have captured. In short, whatever naming structure makes sense for one file format should still make sense for other file formats. If that isn’t the case, it is probably time to re-evaluate your file renaming strategy.

More Detail: For example, I generally use custom text and a sequence number as the structure for the filenames for my photos. The custom text generally relates to the trip or subject matter, and the sequence number is simply a way to ensure each photo gets a unique filename. So, for example, a visit to Rome in 2015 might result in a filename such as “Rome_2015_0001.cr2”.

When you rename photos, the filename extension (such as “cr2” above or “jpg” for a JPEG capture) will be retained. My approach is to sort the photos by capture time and then rename with a sequence number so the sequence number will reflect the capture order. In other words, sorting by filename will be the same as sorting by capture time.

If you want to include other metadata values in the filenames, that would obviously create a different result in terms of the actual filename structure. But that filename structure would still work across a wide variety of file formats and cameras. Perhaps you include the camera serial number in the filename, for example, so you can easily identify photos from one camera versus another. As long as a sequence number is included as part of your filename structure, you’ll still have unique filenames for all images.

I personally don’t feel the need to segregate or otherwise organize photos based on the file type or the camera that was used. The file type, for example, is simply another piece of metadata. To be sure, there may be times that I don’t want to see my JPEG captures, for example. But I can easily filter based on that. So my approach is to have a single filename structure for a given set of photos (generally for all photos within a single folder), and use other metadata values as needed to locate the specific images I’m looking for.

For example, in some cases I’m looking for my highest quality images from a trip, and those are most likely going to be RAW captures from my digital SLR. So I could simply filter based on the camera model, or filter based on the RAW capture format, or a variety of other criteria. But I prefer to have a single filename structure with a sequence number that correlates to capture order, to simplify my workflow for renaming photos without giving up any flexibility in my workflow in the process.

Today’s Question: Would you be able to explain when use of the quick mask is appropriate [in Photoshop] instead of a regular layer mask?

Tim’s Quick Answer: The Quick Mask feature in Photoshop is actually a tool for creating and modifying selections, while a layer mask is used to identify an area that an adjustment will apply to (or for creating a composite image). Since a selection can be used as the basis of a layer mask, you could use Quick Mask mode to create or modify your initial selection, then create a layer mask based on that selection, and fine-tune from there.

More Detail: Photoshop includes a variety of different tools for creating selections. Most of those tools involve either tracing along the edge of the object you want to select, or identifying the area to be selected based on sampling within the image.

The Quick Mask mode is an option for creating or modifying selections where you paint with white to indicate areas you want to select, and with black to indicate areas you don’t want selected. So, for example, you can use the Brush tool to identify (or modify) the area of a selection, or you could use the Lasso tool to trace along the edge of that selection. In other words, the Quick Mask mode is simply another tool available for creating and modifying selections.

A layer mask is used in conjunction with an adjustment layer (or an image layer) to apply a targeted adjustment (or to create a composite image). With a layer mask you can paint with white to identify areas you want to adjust (or have visible), and you can paint with black to identify areas you don’t want to adjust (or that you want to hide).

So, Quick Mask mode and layer masks are very similar, in that you’re able to paint with white and black to identify areas of the image. The only difference is the context. You can use Quick Mask mode if you prefer painting to define a selection, and then create a layer mask based on the selection. And regardless of how you created a selection (or whether you created a selection at all) you can also paint with white and black on a layer mask to refine that mask that is being used as a “stencil” for the image.

Today’s Question: What do you lose by using the Adobe DNG Converter to convert RAW to DNG and then import into Lightroom? I am on version 5.7 of Lightroom and recently got a camera that is not supported in that release (primarily used for video but occasionally stills). I am reluctant to upgrade Lightroom, and have been editing the files in Lightroom in the DNG format. What am I missing in terms of the particular camera profiles or anything else by not being on the Adobe supported profile for this camera?

Tim’s Quick Answer: For all practical purposes, most photographers would not be giving up anything at all by converting their original RAW captures to the Adobe DNG format. This is a common approach to working around the lack of support for newer RAW capture formats in older versions of Adobe software applications.

More Detail: There is the potential to lose access to certain “private” metadata that your camera may have included in the RAW capture, and that the Adobe DNG Converter doesn’t know about. However, the actual original capture data and the standard metadata (such as color temperature settings, for example) would be preserved.

The only other disadvantage from a workflow standpoint relates to the fact that with the Adobe DNG format all metadata is added to the DNG file rather than to an XMP “sidecar” file. I prefer to enable the option in Lightroom to write metadata updates to my original captures (found on the Metadata tab of the Catalog Settings dialog). This provides a real-time backup, and also ensures compatibility across different applications that might show the metadata for my images.

My preferred backup solution involves synchronizing my source drive to a backup drive. With RAW captures if I make a change to an image, only the XMP file on my hard drive is actually updated, with the RAW file remaining unaltered. That XMP file is very small compared to the original RAW capture, so my synchronization backup requires very little time. By contrast, the same update for a DNG file would cause the entire DNG file to be updated, resulting in more data needing to be synchronized during backup.

But in terms of the actual contents of your photo, there is really no significant reason to avoid the conversion to Adobe DNG if you prefer not to upgrade to the latest version of Lightroom (or Photoshop). All of the original pixel data will be preserved when the Adobe DNG Converter processes your captures. That said, my personal preference would be to preserve a copy of the original RAW capture files, just in case those ever prove useful in the future.

Today’s Question: Do you feel there’s value for the money invested in purchasing the latest model colorimeter if you already own and use one from two or three models earlier?

Tim’s Quick Answer: As long as there is no reason to suspect that your existing colorimeter is no longer providing accurate results, in my opinion there is no reason to purchase a newer colorimeter.

More Detail: For those unfamiliar, a colorimeter is a device used to measure the color and tonal values presented by your computer’s monitor display, which in turn are used to create a profile for the purpose of ensuring a more accurate display on that monitor.

To be sure, there have been some improvements with the latest models of colorimeters. However, from my perspective the accuracy of older colorimeters (going back at least a few years) is still very good. So as long as you are getting accurate results with your monitor calibration and profiling, I don’t see any reason to upgrade.

Of course, for anyone who is not already calibrating and profiling their monitor display, I very highly recommend purchasing a package that includes a colorimeter and associated software for ensuring the most accurate display possible. One of the tools I consider to represent the best value in this regard is the ColorMunki from X-Rite, which you can learn more about here:

http://timgrey.me/munkidisplay

Today’s Question: In the last few days I’m unable to use the Quick Selection Tool [in Photoshop]. I can have a plain blue sky and once I drag the quick selection tool over the sky I just get a sausage shaped selection the diameter of the tool. No pixels outside the diameter of the tool are selected. Have you any suggestions what the problem could be?

Tim’s Quick Answer: If you’re getting a selection with an odd shape when using the Quick Selection tool in Photoshop, the issue is almost certainly that you have the “wrong” layer active on the Layers panel. In most cases the best solution is to simply turn on the “Sample All Layers” checkbox on the Options bar for the Quick Selection tool.

More Detail: The Quick Selection tool will by default only sample the currently active layer on the Layers panel. So, for example, if an adjustment layer is active you will only be creating a selection based on the contents of the layer mask for that adjustment layer. Similarly, if you have an image cleanup layer active on the Layers panel, the Quick Selection tool will be creating a selection based on that layer (which likely contains relatively few pixels) rather than being based on the overall image.

The simplest solution is to turn on the “Sample All Layers” checkbox on the Options bar after selecting the Quick Selection tool, so that your selection will be based on the overall composite pixel values in the image, rather than being based on the currently active layer on the Layers panel.

In some cases, of course, you may prefer to create a selection that is based on the contents of a specific layer. In that case, you can turn off the “Sample All Layers” checkbox on the Options bar, but you then need to be sure to select the desired layer on the Layers panel by clicking on the thumbnail for that layer.

It is worth noting that the size of the brush for the Quick Selection tool can also have an impact on the selection that is created. If the brush size is too small, the selection will not cover a large enough area because the tool will not be sampling enough pixel values. You can adjust the brush size using the left and right square bracket keys (‘[‘ and ‘]’) on the keyboard. In general I recommend using a brush that is as large as possible for the area you need to select whenever you are working with the Quick Selection tool.

Today’s Question: I understand the exclamation point in Lightroom’s grid view (I think) but I thought that I should still be able to see a preview even if hard drive containing image was disconnected. Can you offer a solution?

Tim’s Quick Answer: Under “normal” circumstances you should indeed be able to see the thumbnails (and even the larger previews) for all of the images in your Lightroom catalog, even when the source images are not available. For any images for which a thumbnail or preview is not displayed, rendering new previews when the source images are available should solve the problem.

More Detail: Generally speaking, the previews for your photos are generated when the images are imported into your Lightroom catalog. I recommend using the “Standard” option for previews during the import process. If you have considerable free hard drive space you can also use the “1:1” option. As long as this process completes before you quit Lightroom (or disconnect an external hard drive) the previews will be available and visible whenever you have that catalog open in Lightroom.

When thumbnails and/or previews are not available for some of the images in your Lightroom catalog, you can simply render new previews for those images. You do need to have the images available for that process to work, which means you can’t have any images that display the exclamation point indicating the source file is not available.

So, for example, if all of your photos are stored on an external hard drive, you’ll first need to connect that hard drive. You could then select the images that need to have previews rendered, but in most cases I find it easier to simply select all photos within a folder that has some missing thumbnails or previews. You could navigate to a folder with some missing previews, then choose Edit > Select All from the menu (or press Ctrl+A on Windows or Command+A on Macintosh). Then, while in the Library module, choose Library > Previews > Build Standard-Sized Previews from the menu (if you prefer full resolution previews you can choose “Build 1:1 Previews” from that menu instead).

Lightroom will show you the progress of the preview rendering on the identity plate at the far left of the top panel. When that process is complete, all of the images you build previews for will have both thumbnails and previews visible even when the source images are not currently available.