Ask Tim Grey

Today’s Question: I need to purchase another couple of lenses. I shoot with a Canon and am considering purchasing a lens other than Canon, because of the big price difference. What do you think of the image quality in some of the bigger name off-brand lenses?

Tim’s Quick Answer: I have been very happy with a variety of lenses from third-party manufacturers. I think the most important thing to keep in mind is that each lens should be evaluated individually, and you can’t make broad assumptions about quality based only on the manufacturer of a given lens.

More Detail: I also happen to use primarily Canon cameras. To be sure, there are some excellent lenses made by Canon. There are also some lenses that Canon makes that aren’t especially great in terms of overall image quality. In general those lenses that don’t produce the highest image quality are lenses aimed at offering a lower price point compared to the top-end lenses. But the point is that you can’t assume a lens produces images of exceptional quality simply based on the name of the manufacturer.

I have also had the opportunity to test out a variety of lenses from different manufacturers, and I own lenses from different manufacturers. I’ve been extremely happy with some of those third-party lenses. In some cases the lens is one at a lower price point but with quality that is very close to that of the more expensive comparable lens from the camera manufacturer. And in some cases the third-party lens actually exceeds the quality of the lens from the camera manufacturer.

The biggest challenge in my mind is evaluating various lenses, since there are so many variables involved. Some photographers might be willing to pay any price for the lens of the highest quality, for example, while another photographer is looking for a better value with a lens at a lower price point.

There are also many factors that impact overall image quality as well as the utility of the lens. You’ll want to consider prime versus zoom, maximum aperture, whether or not stabilization technology is improved, size and weight, and many other factors.

One source of information I’ve found helpful as a starting point for getting a sense of relative quality for different lenses is the DxOMark ratings. You can view the scores in various categories for a number of different lenses on the DxOMark website here:

http://www.dxomark.com/lenses/

You might be surprised to find that in some cases the less expensive third-party lens actually scores better than the more expensive lens with similar specifications that is manufactured by the same company as the camera.

And, of course, there are also DxOMark scores for cameras in addition to those for lenses. But I most certainly would not hesitate to purchase a lens from a manufacturer other than the camera manufacturer if that particular lens met my specific needs.

Today’s Question: I was at your presentation at Photoshop World yesterday, and was hoping you could help me with a detail I missed in my notes. You were working on a photo of a monkey, creating a layer mask for just the monkey. You showed how painting with a normal brush would damage the fur, but I missed the “trick” for how to change the brush to help protect the fur while you were painting. Could you remind me?

Tim’s Quick Answer: The “trick” I demonstrated yesterday involved the use of the Overlay blend mode when painting with black or white on a layer mask. This allows you to gradually build up a lightening or darkening, helping to reduce the risk of painting completely over fine details.

More Detail: The example in this case involved the creation of a selection for a furry animal (a macaque in this case). Because the fur is a bit translucent, it can be difficult to create a good selection. In this type of situation, I’ll often simply create an initial layer mask based on the initial selection. Viewing that layer mask directly (by holding the Alt key on Windows or the Option key on Macintosh while clicking on the thumbnail for the layer mask on the Layers panel), you are able to see the specific details of the mask, including gray areas that should be black or white.

Using the Brush tool, you can set the colors to the defaults of white and black by pressing “D” on the keyboard, and switch between white and black as needed by pressing “X” on the keyboard.

The trick in this case is to also change the blend mode for the Brush tool from Normal to Overlay, using the Mode popup on the Options bar. This allows you to effectively dodge and burn on the layer mask, rather than simply painting with black and white.

With this technique, it is still possible to harm the detail in the image, such as the fur in this case. However, it will generally require multiple brush strokes to eliminate those details altogether. So with a little bit of careful painting you can clean up details around the edge of the object defined by your layer mask (and within the edges of that object) without having a significant impact on the details of the edge of that object.

Today’s Question: You said [in yesterday’s edition of the Ask Tim Grey eNewsletter] that you don’t recommend limiting the maximum value for white in your photographic images. I’ve often heard that the whites should be set to no brighter than 250 or even lower. Why don’t you think that is necessary?

Tim’s Quick Answer: Put simply, I prefer to retain the maximum possible range of color and tonal values for my photo. In my mind, you should only restrict that range if you have a good reason to do so. If you have such a reason, it probably applies on a per-image or per-print basis, not across your entire library of photographic images.

More Detail: If, for example, your printer is not able to produce discrete values for the brightest shade of white for the specific ink and paper combination you’ll be printing to, then you could reduce the maximum white value to “fit” the range for the photo into the range supported by your printer.

However, if you are printing your photos using a photo inkjet printer, this probably isn’t an issue for you. Many photo inkjet printers have a difficult time producing discrete values for the darkest blacks, but they generally don’t have difficulty with the brightest whites.

Some monitor displays and digital projectors may have difficulty producing a full range of bright values, but that is often the result of incorrect settings (or a lack of calibration) rather than a true issue with the display.

When I hear a photographer say that they adjust the maximum white value for their photos down to something less than 255, the first thing I want to know is why they are doing that. Again, if this adjustment were being applied to compensate for limitations of a printer or other output, that would make sense. But as far as I’m concerned, limiting the white value across all images to something below 255 makes absolutely no sense.

Some images don’t have a full tonal range from black to white in the first place, and some images don’t need to be adjusted to include that full range. But for images where it makes sense to have a full range from black to white, in almost all cases I want to optimize my photo so that white really is white, not some value that is darker than white.

Frankly, I would be more understanding if we were talking about keeping the black value up at a higher value than true black considering the limitations of many printers. But that’s a different matter altogether, and even then I would still retain a true black in my master image in most cases.

Today’s Question: Arthur Morris asked a question in his blog about checking the RGB values in Lightroom. When I use the eyedropper tool it shows a value in percentage. Is there a way to show the actual RGB values?

Tim’s Quick Answer: It is possible to view RGB values in Lightroom as 8-bit per channel values (0 to 255) rather than as a percentage (0-100), but only by enabling the Soft Proofing display in the Develop module. It is critical to keep in mind that the Soft Proofing preview (and therefore the RGB value presented) are based on the specific profile and settings you establish for the soft proofing display, and thus don’t necessarily represent the actual final RGB values for the image.

More Detail: When you move your mouse over the image in Lightroom’s Develop module, the RGB values for the pixel under the current mouse position will be displayed below the histogram at the top of the right panel. Those values are displayed as a percentage rather than the range from zero to 255 that are commonly used to describe RGB data.

You can turn on the Soft Proofing checkbox on the toolbar below the image preview area to have the RGB values shown as 8-bit per channel RGB values (0-255) rather than as percentages. However, those values will be based on the settings established for soft proofing, meaning the values are only meaningful in the context of a specific printer, ink, and paper combination.

What that translates to is that I recommend only using the Soft Proofing option if you are indeed preparing a photo to be printed, and you need to evaluate the output you can expect based on a specific printer, ink, and paper combination.

For more general purposes, I recommend leaving the Soft Proofing checkbox turned off while applying adjustments to your images and evaluating the overall photo. That means you’ll see RGB values as a percentage rather than the 8-bit values you might be accustomed to. But a little bit of math can provide a translation, and with a little bit of experience you’ll gain an understanding of how the values relate to each other.

It is worth noting that the 8-bit values themselves aren’t a full representation of the information in your images, assuming we’re talking about RAW captures, for example. Lightroom actually processes your photos (in the Develop module) with a 16-bit per channel workflow. In other words, the actual underlying values for a photo could range from zero to 65,536, not just zero to 255.

I should also hasten to add that I don’t agree with Arthur Morris’ suggestion that the brightest value for an image should have RGB values of around 240 or so. As far as I’m concerned there is no reason to restrict your processing of a RAW capture to avoid white values that are brighter than a specific value. With some print workflows there used to be (and in some cases still is) a reason to keep the whites from getting too bright. That isn’t the case today for most workflows. Restricting your bright values arbitrarily is only limiting the dynamic range of your final image, without providing a true benefit.

Today’s Question: I recently upgraded my version of Photoshop CC, and now the “Save for Web” command is missing. Has this feature been discontinued? I’ve been using this option to create PNG images with transparency, and want to be able to continue using “Save for Web”. What happened?!

Tim’s Quick Answer: In effect, the “Save for Web” command previously found on the File menu in Photoshop has simply be renamed to “Export”. There is an option for “Quick Export as PNG”, or you can choose “Export As” to configure the settings similar to what you had previously done with the “Save for Web” feature.

More Detail: The “Quick Export as PNG” command will create a PNG that preserves transparency, so this option will likely work perfectly well for you. When you’re ready to save an image as a PNG (Portable Network Graphics) file, simply choose File > Export > Quick Export as PNG from the menu. This will bring up the Save As dialog, where you can specify the filename and location for the PNG image that will be created. Click the Save button, and the PNG will be saved.

If you prefer to configure specific settings for the PNG image being created, you can instead choose File > Export > Export As from the menu. This will bring up the Export As dialog, which allows you to configure all of the various settings for the PNG image (or a JPEG or GIF, for example) very similar to the approach you would have taken with the “Save for Web” dialog in previous versions of Photoshop.

If you prefer to use the previous “Save for Web” dialog, you can still access that dialog in the latest version of Photoshop. Simply choose File > Export > Save for Web (Legacy) from the menu, and you’ll see the Save for Web dialog you’re familiar with.

Today’s Question: With the Crop tool I can draw a rectangle that is exactly 5 inches by 7 inches, for example. But what if I don’t want to crop? What if I just want to select an area with that span? Or draw a rectangle shape exactly that way? Can either of these tools be done to an exact size?

Tim’s Quick Answer: Yes, with most of the selection and shape tools (such as the Rectangular Marquee and Rectangle tools in this example) can be used to create a shape of specific dimensions in inches (or any other unit of measure). You’ll first want to confirm the image dimensions and resolution in the Image Size dialog, and then you can specify the shape size using the settings on the Options bar.

More Detail: When you specify dimensions for a shape, those dimensions are affected by the pixel per inch (ppi) resolution for the image. In other words, since Photoshop is really dealing with pixels, in order to communicate inches accurately you need to specify how many pixels should be counted as one inch. For example, when printing you will typically use a resolution of around 300 pixels per inch.

To review (or change) the ppi resolution for an image in Photoshop, choose Image > Image Size from the menu to bring up the Image Size dialog. There you’ll see a pixel per inch resolution, though you can also change this resolution to reflect centimeters per inch if you prefer.

If you want to change the resolution for the image, first turn off the Resample checkbox, so the number of pixels in the image can’t be changed. Then set the Resolution value to the desired number, and click OK to apply the change. Note that with this approach you are only changing the pixel per inch resolution for the image, without actually changing the size (the number of pixels) for the image.

Now you are ready to specify the specific size for a selection or shape using inches as your unit of measure. With the Rectangular Marquee tool, for example, you can choose the “Fixed Size” option from the Style popup, and then enter values for Width and Height. For the Rectangle tool you will always see the W (Width) and H (Height) fields on the Options bar.

The default unit of measure for the Width and Height values is pixels, which is abbreviated “px” after the numeric value. You can change the unit of measure by simply changing this text. So for five inches you could enter “5 in” for example. In addition to “px” for pixels and “in” for inches, you can also specify dimensions in centimeters using “cm”.

With the dimensions established, you can easily create the selection or shape at the desired size by clicking within the image. By default, that selection or shape will then be created automatically, with the point you clicked within the image becoming the top-left corner of the selection or shape.

Today’s Question: I just learned about Lightroom presets. Can you provide some guidelines for selection? How do I know which are safe?

Tim’s Quick Answer: Presets in Lightroom simply represent saved settings. That means those presets are safe to use (provided you know what they do and actually want that task performed). It also means that anything you can accomplish with a preset you could also accomplish on your own by establishing specific settings within Lightroom.

More Detail: Among the more common presets found for Lightroom are Develop presets. These presets simply save specific settings for the adjustments available in the Develop module. There is nothing you can accomplish with a Develop preset that you couldn’t also accomplish through the use of the adjustment controls within the Develop module.

In other words, if you purchase a set of presets for Lightroom’s Develop module, what you’re paying for is the convenience of having those settings saved for you. Presets can be incredibly convenient, and they can also provide creative inspiration for your photos. But those presets are just saved settings, and thus are only able to set existing options within Lightroom.

So, if you see a set of presets you like, there is no reason to avoid them. And by using such presets, you may find that in addition to getting some additional creative inspiration for your photos, you may learn how to make better use of Lightroom in the process.

Today’s Question: Is it possible to adjust the color for videos in Lightroom? When I go to the Develop module it says it isn’t supported for video.

Tim’s Quick Answer: Yes, it most certainly is possible to apply limited color corrections to video clips within Lightroom. The adjustments can be applied via the Quick Develop controls in the Library module or via a present created in the Develop module. However, you must then export the video to create a new version with the corrections applied.

More Detail: For a simple approach to correcting color (or applying other general adjustments) to videos in Lightroom, you can use the controls found in the Quick Develop section of the right panel in the Library module. Simply select the video you want to correct, and pause the video on a frame that is representative of the overall video. Then click the “single arrow” button for the desired adjustment to apply a small change, or the “double arrow” button to apply a larger change. For example, you can click the right arrow button for Temperature under the White Balance heading to shift the color toward yellow, or click the left arrow button to shift the color toward blue.

You can also use a preset from the Develop module to apply corrections to a video. First you’ll need to capture a still from the video. To do so, first go to the frame in the video that you would like to capture. Then click the “Frame” button (the rectangular icon) on the set of controls below the video and choose “Capture Frame” from the popup.

Next, go to the Develop module, and apply adjustments to the frame you captured. Note that only a subset of the adjustments is actually available for video clips, so you’ll want to restrict yourself to those adjustments. These include the Auto options, White Balance, Exposure, Contrast, Whites, Blacks, Saturation, Vibrance, the Tone Curve, Treatment (color versus black and white), Split Toning, Process Version, and Calibration. Once you’ve applied the desired adjustments, create a preset based on those adjustments.

With a Develop preset created, you can then apply that preset to one or more videos in the Library module. Select the desired videos, and then click the Saved Preset popup in the Quick Develop section of the right panel and choose that preset.

Again, to actually make use of the video with the adjustments applied you will need to export the videos from Lightroom. Just be sure you don’t use the “Original, unedited file” option from the Video Format popup in the Video section of the Export dialog, as doing so will cause the original video to be exported without any adjustments applied.

Today’s Question: Is there any reason why you would choose to use Lightroom or Photoshop versus Canon’s Digital Photo Professional for RAW conversion? Everything I hear is that the raw converter is superior to Lightroom or Photoshop converters.

Tim’s Quick Answer: There are two key reasons I use Lightroom (and Photoshop) to process my RAW captures, rather than the software from the camera manufacturer (such as Digital Photo Professional in the case of Canon cameras). First, I am able to get excellent results with my images using Lightroom. Second, workflow efficiency is an important consideration to me.

More Detail: To be sure, when using RAW processing software created by the camera manufacturer, there are some potential advantages that may improve image quality. Put simply, the camera manufacturer understands the image sensor in your camera better than just about anyone else, and can use that knowledge to make their software better at processing RAW captures from a given sensor.

That said, there have been some rather dramatic improvements in RAW-processing software across the board over the years, to the extent that I consider the advantage of using the software provided by the manufacturer to be (in many cases) a relatively modest advantage.

I have tested a wide variety of software tools on many different images, and have found that in most cases the differences in results translate into simple differences, not dramatically different results in terms of image quality. I have also found that I prefer the workflow within Lightroom for organizing and optimizing my images, and don’t like the notion of using other software outside of this workflow for processing the initial RAW captures.

I certainly encourage photographers to evaluate different solutions based on their own specific needs. In the context of RAW processing, I highly recommend testing out various software solutions to see what works best for you in terms of both image quality and workflow efficiency. I’ve been impressed with many of the software tools that are currently available, but on balance I find that a Lightroom-based workflow best suits my specific needs.

Today’s Question: I’ve been wanting to create negatives from my digital images in order to make chemical-based prints. I have both Lightroom and Photoshop Elements. I can make a negative using Photoshop Elements, but I would like to stay in Lightroom. Is there a way in Lightroom to create a negative image?

Tim’s Quick Answer: It is possible to create a negative version of an image, but in this context it won’t be as simple as simply inverting the photo. Instead you’ll need to create a customized curve optimized for the final output conditions, which can require considerable trial-and-error to accomplish.

More Detail: The key to an inverted image is an inverted Tone Curve adjustment. To get started, make sure you are in the Point Curve mode rather than Parametric mode. If you see sliders for Highlights, Lights, Darks, and Shadows below the curve display in the Tone Curve section of the right panel in the Develop module, click the Point Curve button at the bottom-right of the Tone Curve section to switch modes.

Next, drag the black end point at the bottom-left of the curve display all the way to the top-left corner, and drag the white end point at the top-right of the curve display all the way to the bottom-right corner. This will create a basic inverted image, but it isn’t necessarily an optimal result for your final output.

If you are working with a black and white image, the process will be relatively straightforward. You can simply choose the “Black & White” option under the Treatment header in the Basic section of adjustments, and you’ll have a grayscale inverted image at this point.

However, even with a black and white image the simple inversion won’t necessarily provide an optimal tonal distribution in the final print based on a negative created from the adjusted image. If you are working with a color image the process is even more complicated, with a need to adjust the individual color curves found on the Channel popup below the histogram display.

So, it is most certainly possible to create an inverted image in Lightroom, but creating an adjustment that will produce good results in a print based on such a negative image can be a bit of a challenge. That said, once you have identified a set of adjustments that produce a good print, you can save a preset based on those adjustments to provide a good starting point for other images you want to print in the same way.