Ask Tim Grey

Today’s Question: All things being equal, with a raw capture is it better to raise the ISO rather than underexposing and brightening in post? A specific challenge for me is holding detail in moonlit scenes without blowing out the moon. Under-exposed holds more highlight detail while darks can be dug out in post. Brighter exposure cooks the high lights irretrievably.

Tim’s Quick Answer: Generally speaking, it is better to raise the ISO setting rather than under-exposing and brightening in post-processing. Note, however, that in the type of scenario described in the question, bracketing several exposures to assemble into a high dynamic range (HDR) result can improve quality in terms of noise in the image.

More Detail: As noted in Monday’s Ask Tim Grey eNewsletter, raising the ISO setting doesn’t increase the sensitivity of the image sensor in the camera. Rather, when you raise the ISO setting you are under-exposing the image and then having the camera apply amplification to the signal recorded by the image sensor. The result is generally an increase in noise in the image.

However, as outlined in an article that appeared in the July 2016 issue of Pixology magazine, if you under-expose without raising the ISO, you’ll generally get more noise in the final image than if you had instead raised the ISO setting in the camera.

As I’ve also covered before, making sure to expose an image as brightly as possible without actually losing highlight detail will help ensure minimum noise and maximum detail in the image. Therefore, in the example from today’s question you would want to make sure the moon is as bright as possible without losing any detail.

However, this is a good example of a scenario where you may very well end up clipping shadow detail by creating an exposure for the highlights. You may be able to bring out more visible detail by brightening up the shadows in the image, but that will also reveal noise in those areas.

To help ensure maximum quality, you can create a high dynamic range (HDR) image in this type of situation. This involves bracketing the exposures so you have a capture that retains full highlight detail, and capture that retains full shadow detail (to the point that there isn’t even a true black in the image), and additional exposures in between so there is no more than two stops of separation between the exposures. Those images can then be combined into an HDR image that will have less noise than a single exposure that requires brightening to reveal shadow detail.

Today’s Question: I just read the article in the March issue of Pixology regarding time-lapse photography while using a smart phone. And here I didn’t even realize I had that feature on my iPhone. Question: Is there available on the market a “clamp” that can be attached to a regular tripod that will hold the phone? I have a regular tripod and two travel tripods of varying sizes, and would just as soon use those if possible.

Tim’s Quick Answer: The approach I’ve taken in this scenario is to employ a small tripod for the smartphone that has flexible legs. This type of miniature tripod can easily be attached to the ball head on a larger tripod, providing a secure platform for the smartphone.

More Detail: There are, of course, a variety of approaches you could take when it comes to making use of a tripod for a larger camera to also provide a platform for a smartphone. I find that the most flexible option (no pun intended) is to make use of a miniature tripod with flexible legs for the smartphone, which can then be attached to a variety of different objects, including a larger tripod.

A miniature tripod for a smartphone is convenient for a variety of reasons, and so I will generally carry such a tripod on most trips. Of course, in most cases I will also be traveling with a larger tripod as well as a digital SLR or other camera. By simply adding a miniature tripod to my camera bag, along with a normal tripod, I have greater overall flexibility.

I can use my normal tripod with my larger camera, of course. And I can use the miniature tripod for more casual scenarios when capturing photos or videos with a smartphone. Even better, I can essentially combine the two tripods to provide a taller platform for the smartphone.

In many cases I will actually use the smartphone to capture time-lapse videos, rather than capturing a sequence of still captures with my normal camera. You can view a recent example featuring several time-lapse videos I captured while on a ship transiting the Panama Canal on my YouTube channel here:

https://youtu.be/tQEo2L5dTD0

There are a wide variety of miniature tripods with flexible legs that work well for just about any smartphone. One option that I’ve made use of can be found here:

https://amzn.to/2sCa7iP

Today’s Question: While I never actually did it, I know it was possible to “push” process film captures to get a higher effective ISO. Is such an approach possible with digital?

Tim’s Quick Answer: While push processing in the traditional sense is not possible with digital captures, a similar result would be achieved by simply raising the ISO setting, or by under-exposing a capture and brightening the image in post-processing.

More Detail: Push processing with film photography involved under-exposing photos and then leaving that film in the developer solution for a longer period of time or at a higher temperature (or both). The result was greater detail and a larger visible grain structure.

Using a higher ISO setting provides something of a digital equivalent to push processing. When you raise the ISO setting on the camera, you’re not truly increasing the sensitivity of the image sensor on the camera. Rather, you are having the camera apply increased amplification to the signal gathered by the image sensor during the exposure.

Increasing the ISO setting therefore involves what is essentially under-exposing the scene based on the actual sensitivity of the image sensor, and then compensating with amplification in the camera. Similar results could be obtained by under-exposing without raising the ISO setting, and increasing the brightness of the image in post-processing. Generally you’ll get better results by raising the ISO in the camera, but the overall effect is similar.

In either case, you’ll get a result that is somewhat similar to push processing with film. It isn’t exactly the same due to the different mechanics involved (chemistry versus digital signal processing), but in concept they are similar.

Today’s Question: In a recent Ask Tim Grey you stated: “To help compensate for the issues of having a flash that is so close to the lens, I will more often than not reduce the strength of that flash so it is contributing light that supplements (rather than overpowers) the ambient light.” Would you please expound on how you go about doing this?

Tim’s Quick Answer: The specific mechanics of how to apply exposure compensation for the flash will depend on the specific flash (and camera system) you’re using, as well as your exposure mode for the flash. But as a general rule, you can apply a positive or negative exposure compensation to adjust the amount of light the flash is contributing to the exposure, very similar to how you can apply exposure compensation based on the metering in the camera when capturing a photo without flash.

More Detail: Some flash units include a built-in exposure compensation feature. If the flash is set to a manual exposure mode, instead of an exposure compensation based on stops of light for the flash, there will generally be a strength setting for the flash that you can adjust. This is often expressed as a fraction of total output, for example.

More often with newer cameras, both with built-in flash and external flash units, you can apply a specific exposure compensation setting using the menu on the camera’s LCD display.

The point is that the specific approach will depend on the equipment you’re using. You can obviously check the manual for your specific flash and camera model. In general you will likely find settings on the menu system for your camera, providing an exposure compensation setting for the flash. The camera I typically use, for example, includes a built-in flash. I sometimes use an external flash mounted on the hot shoe, however, and the menu on the camera enables me to adjust the compensation for either flash based on my current configuration.

With previous camera models and older flash units, the compensation was found on the flash unit itself. With the controls on the back of the flash you could apply a positive or negative exposure compensation for the flash, to increase or decrease the amount of light the flash was contributing to the overall exposure.

So again, the specific mechanics will vary based on the specific gear you’re using, but the overall concept is the same. You simply adjust the strength of the flash to change the degree to which the flash is contributing to the overall exposure. Some trial-and-error may be required, but with a little bit of practice you’ll be able to anticipate the degree to which you need to apply exposure compensation to the flash as part of your overall exposure settings.

Today’s Question: During one of your presentations you restarted Lightroom [Classic CC] and I noticed the image that appeared while Lightroom was loading included your GreyLearning logo. How do you customize that startup image?

Tim’s Quick Answer: You can replace the default splash screen in Lightroom Classic CC by simply creating an image of up to 900 by 600 pixels and saving it into the “Splash Screen” folder based on your operating system.

More Detail: The first step to customizing the splash for Lightroom, of course, is to actually create the graphic you want to use for this purpose. Many photographers, for example, prefer to have their company logo or other promotion information appear on the splash screen. This provides a small promotional opportunity when you launch Lightroom with clients to review images.

The splash screen image can be up to 900 pixels wide by 600 pixels tall. Save the image as a JPEG or PNG file, putting it in the appropriate folder based on your operating system.

For Macintosh users, you can get started by navigating to the Library folder. To do so, hold the Option key on the keyboard while choosing Go > Library from the menu. Note that the Library option does not appear on this menu if you’re not holding the Option key. Within the Library folder, navigate to Application Support > Adobe > Lightroom > Splash Screen.

For Windows users you’ll want to start by navigating to the Users folder on your system hard drive (drive C: by default). Then continue navigating to AppData > Roaming > Adobe > Lightroom > Splash Screen.

Once you’ve navigated to the appropriate folder, place your custom splash screen image into that folder. When you restart Lightroom, your customized splash screen will appear while Lightroom is loading.

Today’s Question: In Lightroom how do you rename the previous import?

Tim’s Quick Answer: You can rename photos after import by selecting them and choosing Library > Rename Photos from the menu. In the case of the previous import, note that you can find those images in the Previous Import collection in the Catalog section of the left panel in the Library module.

More Detail: It is possible to rename photos during import into Lightroom, of course. But you can also rename later in your workflow. You may have forgotten to rename during import, or you might want to wait until after you’ve deleted outtakes, so you won’t have gaps in the filename numbering.

The first step is to select the photos you want to rename. If those photos are the last images to be imported, you can select the Previous Import collection from the Catalog section of the left panel in the Library module. You can then choose Edit > Select All from the menu to select all of those photos, and then choose Library > Rename Photos to initiate the renaming process.

If you need to select other photos, you can navigate to the appropriate folder and select all (or some) of the photos. Then choose the Rename Photos command to bring up the Rename Photos dialog. Note that the title bar for the dialog will indicate how many images you’re renaming, so you can get a sense of whether you’ve selected the correct range of photos.

The renaming process later in your workflow is the same as during import, in that it involves the use of a template. So you can choose a template from the File Naming popup, or choose “Edit” from that popup to bring up the Filename Template Editor dialog where you can define a structure for renaming photos.

In the Rename Photos dialog you can then fill in any other details, such as if the template you’ve selected includes a Custom Text or Sequence Number field. Then click OK to apply the renaming to the selected photos.

Today’s Question: I’m only using Photoshop, not Lightroom. I’ve seen a lot of information about creating presets for applying effects in Lightroom. Is it also possible to create presets in Camera Raw?

Tim’s Quick Answer: Yes, you can indeed save settings in Camera Raw, much as you can save presets in Lightroom. The commands are found on the popup menu at the top-right of the adjustments panel in the Camera Raw dialog.

More Detail: The first step to saving Camera Raw adjustment settings is to actually apply those adjustments to an image. For this purpose I generally open a “test” image that I’m not too worried about, so I don’t have to be concerned about resetting the adjustments for the photo.

I then recommend resetting the current adjustments to the default settings. You can do so by clicking the panel popup menu button at the top-right of the adjustment controls and choosing “Reset Camera Raw Defaults” from the popup menu. Then apply all of the various adjustments you’d like to save.

When you’re finished applying your adjustments, click the panel popup menu at the top-right of the adjustments once again, and choose “Save Settings. In the dialog that appears you can choose which specific categories of adjustments you’d like to include in your saved settings. Make sure the checkbox is only turned on for the specific categories you want to include in your saved settings, and click the Save button.

In the dialog that appears, enter a name for the settings you’re saving. If you’d like, you can also create or open a subfolder within the Settings folder. Then click the Save button to actually save your settings. Those settings will be preserved in an XMP file, much as settings for raw captures processed with Camera Raw.

In the future you can apply your saved settings to an image from within Camera Raw. Simply go to the popup menu once again and choose Load Settings. Then select the XMP file created when you saved the settings, and then click the Load button. The saved settings will be applied to the current image within Camera Raw, so you can refine those settings as needed and then open the photo.

Today’s Question: When I open an image in Photoshop, it’s always necessary for me to choose View > Fit on Screen from the menu to maximize the image size before I can proceed with anything else. Is there a way to instruct Photoshop to perform that step automatically every time an image is opened?

Tim’s Quick Answer: Yes, you can have Photoshop always size images with the “Fit on Screen” zoom setting by creating an action that you activate to be run every time an image is opened in Photoshop.

More Detail: The first step to enable Photoshop to always zoom images with the “Fit on Screen” setting is to create an action for this purpose. Start by going to the Actions panel, choosing Window > Actions if the panel isn’t currently visible. Navigate to the folder (or create a new one) in the Actions panel where you want to create the action. Then “Create a New Action” button (the blank sheet of paper icon) at the bottom of the Actions panel to start the process of creating an action.

In the New Action dialog, type a meaningful name for the action, such as “Zoom Fit on Screen”. Confirm the desired folder is selected for the action, and then click Record to begin creating the actual action. Then click on the panel popup menu at the top-right of the Actions panel (it has an icon of a set of four horizontal lines) and choose “Insert Menu Item” from the popup menu.

When the Insert Menu Item dialog appears, go to the menu bar and choose View > Fit on Screen. Then click OK in the Insert Menu Item dialog. You can then click the “Stop Recording” button (the white square icon) at the bottom of the Actions panel to stop recording the action.

Next, go to the menu bar and choose File > Scripts > Script Event Manager. In the Script Events Manager dialog turn on the “Enable Events to Run Scripts/Actions” checkbox if it isn’t already turned on. Then choose “Open Document” from the Photoshop Event popup. Below that, set the option button to Action (rather than Script). Select the folder where you created the action, and the action you created with the Fit on Screen command. Click the Add button to add this event, and then click the Done button to close the Script Events Manager dialog.

At this point, every time you open an image in Photoshop (whether directly or via another application such as Adobe Bridge), the image will automatically resize with the “Fit on Screen” zoom setting.

Today’s Question: You said that you consider Lightroom Classic’s backup during import to be a “temporary” backup. Why is that, and does it mean you don’t recommend using this backup option?

Tim’s Quick Answer: When you use the option to create a second copy of your photos during import into your Lightroom catalog, the backup is not what I consider a “complete” backup of the source files. It is still perfectly fine to take advantage of this backup option during import, but I then recommend creating a more complete backup after the import is complete.

More Detail: When importing photos into Lightroom Classic with the “Copy” (rather than “Add”) option, you have the option of creating a second copy of your photos as part of that process. However, the backup copy created when you turn on the “Make a Second Copy To” checkbox in the Import dialog isn’t what I consider a “complete” backup.

When you enable the backup during import, Lightroom will copy the source images being imported to a second location that you specify. However, within the location you select, a subfolder will be created to contain the backup copy of the photos. The name for that folder will not match the name of the folder you are importing your photos into. Instead, the folder will be called “Imported on” with the date of import appended to the folder name.

If you rename the photos during import, that renaming will also be reflected in the backup copy. However, metadata updates you apply during import (such as by using a metadata preset or entering keywords) will not be written to the backup copy of the images. The source images can have those metadata updates applied to the source images (rather than only being included in the catalog) if you have enabled that option in the Catalog Settings dialog.

For these reasons, I treat the “Make a Second Copy To” option during import as a temporary backup solution. I do prefer to make use of this option, so that I have an “extra” backup of my photos immediately upon import into my Lightroom catalog. However, once I’ve then created a synchronization backup for two or more backup drives (using GoodSync, http://timgrey.me/greybackup), I can discard the backup Lightroom created during import.

To be sure, I’m never in a hurry to discard the “extra” backup created when I import photos into Lightroom. But when I need to free up hard drive space on the drive where I store those import backups, I can comfortably delete those backups since I already have two (or more) additional backup copies of all of my photos.

Today’s Question: I recently read a reference to HSL as a color space. I had never heard of this. How does the HSL color space relate to RGB, and is there any need for me to consider working in HSL?

Tim’s Quick Answer: HSL (or HSB) is actually a color model, rather than a color space. A color model is a method of describing colors, while a color space is a range of colors available for use in an image. What that means is that HSL simply provides a different way to describe color compared to the RGB color model.

More Detail: When using the HSL color model, colors are described based on their hue, saturation, and luminance (or brightness). That typically involves a hue value expressed as degrees around the color wheel, and values for saturation and luminance (or brightness) expressed as a percentage. In the RGB color model the same colors are described based on the amount of red, green, and blue light are combined to create a color. Those RGB values would range from zero to 255 for 8-bit per channel images, and from zero to 65,535 for 16-bit per channel images.

In other words, when working in the RGB model, you could also say that you are working in the HSL model. Both simply provide different ways of describing the same colors. In software such as Photoshop, you aren’t able to switch to the HSL color mode. Rather, you would typically work in the RGB color mode. However, in the Color Picker dialog (and elsewhere) you can see HSL values (referred to as HSB values in the context of Photoshop) in addition to RGB values. There are also other options included, based on other color models, including Lab and CMYK.

When working in software such as Photoshop, you can choose a color space for your photos. So color spaces such as ProPhoto RGB, Adobe RGB, and sRGB describe a specific range of available colors, while a color model determines how those colors are communicated.