Must-Have Photoshop Skills for Photographers, Part 2: Enlarging Images and Large-Format Printing
I hear a lot of questions about preparing Photoshop files for enlargement and output on either a desktop or large-format printer. Unless you’re setting up a tiled print that will be larger than the width of your printer, the process of preparing a file for enlargement on a desktop printer is no different than the process used for a large-format printing.
Some of the specific questions I often hear include:
- How can I tell if my image will look OK as a big print?
- Will the image look different as a big print as compared to a smaller one?
- What color space should I use for my images?
- Should I upsize an image, and if so, how should I do it?
- Should I set up printer-managed color, or use Photoshop-managed color along with an ICC profile?
- What about sharpening?
Before I address these questions, I want to remind you of how important is to get the image right in the camera. The best way to get an image that will look good when it is enlarged is to start off with a solid image. Even so, you may still need to spend a bit more time editing it in Photoshop because enlarging the image can make even the tiniest imperfections more obvious.
How can I tell if my image will look OK as a big print?
Enlargement magnifies both the good and bad in a print. Thus, some prints that look fine as 8x10s don’t work as 16x20s. Generally, you can assume that the good things in a print will look better and the weak points will look worse.
One way to test this is to take an important section of the image, and print just that section scaled up to the size it would be if it was part of the enlarged print. This lets you preview how it would look on a smaller piece of paper, which will save you some time and money.
Will my image look different as a big print as compared to a smaller one?
In many cases it will look different. However, the term “different” has more than one connotation. For example, images with large areas of dark tones or large areas of light tones can shift in how they look when enlarged. The same can be true in images that have large areas of color.
Plus, the perceived sharpness of the image is usually affected when it is enlarged. You’ll find that as you try larger sizes, you’ll reach a point of diminishing returns. Image quality will start to go down, and you’ll know where to stop.
What color space should I use for my printed images?
This can be a tricky question. Generally speaking, JPEGs are produced by a camera in either sRGB (a smaller color space) or in Adobe 98 RGB (a larger color space). If you are shooting JPEG, it is probably best if you leave the image in the color space assigned by the camera, whether sRGB or Adobe 98.
If you are shooting RAW mode, your image does not have a color space assigned to it until you develop it in Photoshop (or Lightroom, Aperture, or other program). When you develop the image, you can specify which color space you want to use. I recommend using Adobe 98 RGB, or Pro Photo RGB.
Should I upsize an image for printing? If so, what’s the best way?
You can upsize any image that is strong enough to retain its quality when enlarged (e.g., sharpness, color, and other attributes). In Adobe Photoshop CS5, there are at least three ways to upsize an image:
- You can use the menu command Image > Image Size, and change the dimensions of the image on-screen. Remember to keep the Resample Image box checked (Fig. 1). This method gives OK results. In my opinion other methods are better.
- You can upsize the image in Camera RAW, using the dialogue box from the bottom of the opening Camera RAW page. In the dialogue box shown in Fig. 2, you can select a larger image size than your original. It will open in Photoshop in this larger size. This method works quite well, provide you start with a strong image.
Should I set up printer-managed color? Or should I use Photoshop-managed color along with an ICC profile?
I recommend letting Photoshop manage your color, as long as you have a good ICC profile for the combination of printer, ink, paper, and resolution you plan to use. Printer-managed color can do quite well, but Photoshop-managed color is often superior. Plus, when you use Photoshop to manage your color, you can use a calibrated monitor to get an accurate on-screen preview of how the colors in your print will look before you hit the print button. This ability to “soft proof” can save you considerable time, ink, and paper.
The red circle on Fig. 4 below includes the important bits. Set the top dialog to “Photoshop Manages Colors”, the middle one to the printer/paper combination you are using, and the bottom one to “Perceptual.”
What about sharpening?
Sharpening is a tool used to enhance the detail in digital images by separating light and dark tones. Entire books have been written about the subject of sharpening. Briefly, sharpening is governed by your artistic goals, the inherent sharpness of the image you captured, the final size of the print, the distance from which the print will be viewed, the type of output device you will be using to make your print, and other factors.
Generally, I suggest adding sharpening in small increments on a separate layer in Photoshop. Then, make a test print. Adding sharpening in conservative doses generally looks better in the end. You can always add another gentle dose of sharpening if the first try doesn’t make the grade.
Sharpening almost always looks more aggressive on your screen than it does in the print. So, unless you have a specialized plug-in such as Nik Sharpener Pro, you may need to experiment a bit to get a solid idea of what will happen when you print the image you see onscreen.
One final tip: Look at prints made by experienced, accomplished photographers and printmakers. Examine the details, including the harmony of tones, color, sharpness, etc.. These can help guide you in improving your printing skills.
Previous posts in this series:
Must-Have Photoshop Skills for Photographers, Part 1: Layers
Must-Have Photoshop Skills for Photographers, Part 1: Layers
It’s often said “there are ten ways to do anything in Photoshop” – and that’s probably true. But one aspect of Photoshop that has no real substitute or workaround is using layers. In my opinion, this is a must-have skill for photographers who edit their own images. In fact, many people who begin editing their images in Lightroom have started going back to using Photoshop layers as part of their workflow.
Many image-editing programs require you to work on the original image. In other words, any change you make affects the original pixels. To change this, you frequently have to step back through a series of “undo” commands, or even start over. This is sometimes referred to as destructive editing.
You can use destructive editing in Photoshop by always working on the original, or Background layer. Below is a screen shot in which I’ve applied a sepia tone effect to half the image. If I want to make a change on a single-layer setup, I’ll have to re-start the project, or at least “undo” the work I’ve done:
On the other hand, Photoshop also provides tools for working on multiple layers, which can be referred to as non-destructive editing.
Quoting from an article in PC Magazine: “in a layered imaging program, objects are placed in separate layers and can be freely moved under and over each other. Objects can always be added, and any object can be removed or changed without affecting the others.”
For example, you can add one image to another on a layer or add type or a graphic element.
This illustration shows how a stack of layers can each have a different color adjustment or effect
Another way to think of layers is that they are like slides (transparencies) stacked on top of each other, and each layer can contain a different adjustment, style, or special effect. Stacked like this each layer can affect the layers below it in the stack.
Viewed together, the layers appear to be a single image. However, you can edit any layer at will without touching the pixels in another layer. Here’s an example:
Each layer can be made visible or invisible, be adjusted independently, or even discarded without affecting the others. One can apply levels or curves adjustments, move a layer, retouch, and more. It is easy to return to an image, adjust one layer, and go back to printing or other production tasks. Very efficient!
You can change the opacity (transparency) of a layer to increase or decrease its effect on layers beneath it.
Going back to the edited black and white image, I've added a color effect to a layer, and I've added my copyright notice as a text layer.
This article is just an introduction to the concept of using layers in Photoshop. Learning how to use layers to their full potential takes a bit of persistence and practice.
One very useful source for tutorials is the Help screen at the top of your Photoshop screen! Adobe provides hundreds of superb tutorials and lessons via on-screen and online text and video files. Next time you open Photoshop, take a look – you’ll be pleasantly surprised.
Don’t worry about whether you have Photoshop CS3, CS4 or CS5. Layers work in all these versions, and earlier ones, too.
Duotone, Tritone, and Quadtone Images in Photoshop
Now that black-and-white photos are more popular than ever, there seems to be quite a bit of interest in toned images that mimic platinum or selenium looks as well. Thanks to the toning features built into Photoshop, it’s relatively easy to make these types of images.
To get started, you first need to do a basic black-and-white conversion. If you’re using Photoshop CS3 or CS4, this is best done with either the Channel Mixer or the Black-and-White command. Figure 1 shows the image I’m starting with, a photo of Yosemite Falls captured from Sentinel Dome.
Figure 1
Once you’ve converted your image to black and white, throw out the color information by selecting Image > Mode > Grayscale. Now you can select the toning options from Image > Mode > Duotone (Figure 2)
Figure 2
You’ll use the same dialog to do duotone, tritone, or quadtone images. The only difference is the number of tones you have to work with.
Let’s start with a duotone to see how the process works. When you first open the Duotone dialog, only one color box will be active. So select Duotone from the popup menu. All of the different color libraries in Photoshop are available for you to work with. I prefer working with the Pantone libraries because the organization is so logical. Click on the black square to start, opening the Color Picker. Now, select Pantone from the Color Libraries (Figure 3).
Figure 3
I’ll do a platinum-toned image to start with. The first color to select (Ink 1) is your darkest tone. In this example I’m going with Pantone 432 C from the Pantone Solid Matte library.
For Ink 2, I select Pantone 421 C (Figure 4). This is my lightest color. Every tone in the image will be within the Ink 1 and Ink 2 range. Where the real power comes in is with the ability to control the curve for each ink color by clicking on the box next to the color sample (Figure 5). While this looks very much like the curves dialog you’re used to, the curve works differently with duotones.
Figure 4
Figure 5
While the standard curves control determines highlight and shadow strength and ramp, the curves control in the Duotones dialog determines the ink volume for that color. In this case, I’ve lowered the levels quite a bit to open up this image detail. You can view the color ramp at the bottom of the curve to get an idea of how the adjustments are affecting your image. Like a standard curves adjustment, click to place a point, and drag up or down to adjust that point.
Here’s the result of my adjustments with a final duotone (Figure 6):
Figure 6
By using more color options you can have even greater control over the finished image while still maintaining much more control over how the colors are applied. Figure 7 shows the settings I’ve used for a tritone version of the Yosemite Falls shot (Figure 8).
Figure 7
Figure 8
As you can see, there is much more image depth and finer variation in the tritone version than in the duotone.
One of the nice things about the duotone dialog is the ability to save your adjustments as presets for future use. If you’re doing a series of images for a show or portfolio, this ensures you have a consistent look from one image to another, something that isn’t easily done with a standard conversion.
Figure 9 shows a sample of a quadtone image where I’ve selected colors from both the Pantone Solid Matte and Pantone Pastel color libraries. Being able to mix color libraries for your tones gives you a tremendous amount of flexibility in creating just the look you’re going for. I’ve found these softer colors are popular with the high school senior crowd (at least the female students) who are looking for something different but aren’t quite ready for the grunge look that is all the rage now.
Figure 9
Finally, if you’re not the type who likes to experiment, Adobe includes a number of excellent presets that you can load and use as is, or modify as needed. To access these presets, click on the menu icon next to the Preset popup menu, and choose Load Preset. Navigate to the Photoshop/Presets folder, and open the Duotones, Tritones, or Quadtones folder. Figure 10 shows a sample from this library, a tritone made from the BMY Sepia 4 preset.
Figure 10
Sharpening Images for Output: Part 1
One of the most common questions I get in workshops and from readers of my books or articles is how to best sharpen a digital image. A properly sharpened image can make a big difference in the perceived quality of a photo, whether it is viewed online or in print. Conversely, nothing screams digital image more than an over-sharpened image.
Sharpening Defined. First, the basics. Sharpening really isn’t sharpening or changing the focus of your image. If you start off with a soft image, no amount of sharpening is going to correct that problem. What is happening when you sharpen is that the contrast of the edges in your image is being enhanced. Figure 1 shows the Unsharp Mask dialog in Photoshop. This is where most people are doing their sharpening work. It might seem easy enough, there are only three adjustment controls to work with.
Figure 1
The Amount slider controls how much the edges will be enhanced. This is pretty straightforward.
The Radius slider determines how wide the edge enhancement effect will be. This is often where people go overboard.
The third control, Threshold, is what sets the boundaries for Photoshop to determine whether a pixel is an edge or not. The higher the number is here, the greater the difference in values needs to be between pixels before they’re considered an edge.
A natural tendency for people new to sharpening is to use settings that are too high, particularly for the Radius. This will lead to a halo effect around the obvious edges of your image like those shown in Figure 2.
Figure 2
A better method of sharpening using the standard tools in Photoshop is the Smart Sharpen option (Filter > Sharpen > Smart Sharpen).
This has a couple of benefits. First, the dialog is resizable, enabling you to see more of your image to get a better idea of the effects your adjustments are having. Secondly, the sharpening algorithms used in Smart Sharpen do a better job of edge-contrast enhancement.
Figure 3
Figure 4
An even better approach is to use one of the third-party sharpening options such as Photokit Sharpener, or Nik Sharpener Pro. Both of these will help you to select the optimum settings for print output or screen display. If you are printing the image, you can optimize sharpening based on the type of paper you plan to use.
When to Sharpen. Sharpening should be done as the last step in your workflow. Do it after all of your other edits have been to the image—just before you save the file for screen display or printing. Because sharpening is a destructive process (you’re changing pixels on the image), you want to do it with the final pixels you’ll be outputting as a print or screen display. If you sharpen prior to sizing for output, you’re liable to end up with an image that has visible artifacting from the sharpening process, or you’ll need to sharpen a second time to fine tune the output – creating more opportunities for image degradation.
If you’re using Adobe Lightroom, this all becomes a little fuzzy because the entire workflow is non-destructive and there is no real concept of resizing until the image is exported or printed. Lightroom uses sharpening techniques based on Photokit sharpener and does a really nice job. There are additional output sharpening options in the Export dialog and in the Print module. In an upcoming post, I’ll cover sharpening from Lightroom in detail.
Camera RAW 101: Why Shoot RAW?
Although blogs and websites are great ways to pick up snippets of useful information and insights, reading (and writing) photography books can help put a lot of complex information into perspective. My newest book was published by Amphotos Books in August.
Entitled Camera Raw 101: Better Photos with Photoshop, Elements and Lightroom, it was written for any digital photographer who is interested in going beyond the preset options in the camera and is ready to take control over the creative process. The book provides the information you need to make RAW work for you, including setting up a preliminary workflow, using and automating Adobe Camera RAW, and basic and advanced conversion options. The book also includes a detailed comparison of Adobe Camera RAW features in Photoshop Elements and Photoshop CS4 and Lightroom 2.1. In the following excerpt from the book’s introduction, I explain why you should shoot RAW and suggest when RAW isn’t the best choice.
RAW files shouldn’t be seen as the lazy person’s way to great images, though. A poorly composed image, an out-of-focus image, or one with gross exposure errors isn’t going to be magically transformed into a quality photograph because you were able to edit the RAW file. It is the responsibility of the photographer to capture the best possible image at the time of capture.
Advantages over JPEG and TIFF: RAW files free the photographer from having to be satisfied with what the camera thinks are the correct values for sharpening, noise reduction, and white balance. The differences can be startling! Since this information is all stored in addition to the file, it becomes possible to make changes to them after the fact. This is where the RAW format becomes so valuable.
When shooting in JPEG the camera processes the color values based on the current white balance setting in the camera to create a final image. The file is then compressed to save space using the current quality setting in the camera. RAW capture, on the other hand, does no color interpretation in-camera but depends on the RAW converter software to handle this task. Hence, you have much more freedom after the capture to either fine-tune the image or make corrections to basic problems, such as improperly set white balance.
RAW is the only capture method that preserves the full color fidelity of the image. With JPEG, you automatically throw away one third of the color information in your image. The sensor in most cameras records data as a 12- or 14-bit file, giving each pixel one of 4,096 levels or more of color. To take advantage of this, you’ll need to shoot in RAW mode. JPEG only supports 8 bits per pixel, reducing the possible colors to 256 per pixel. Less color information means that yu have less latitude when editing the image for final output.
JPEG is a lossy compression method. Every time a file is saved in the JPEG format it loses a little more fidelity.
JPEG and TIFF also apply sharpening and noise reduction at the time of capture. If you’ve set these incorrectly, and don’t catch the error, you have little choice in the edit phase. I strongly feel that the camera does not know what my intended use for an image is and should never be allowed to choose the sharpening or noise reductions it “thinks” I want.
Saving in camera in TIFF is becoming much less common in recent cameras. Although some, such as the Canon DSLRs, actually tag their RAW files as TIFF, these are not true TIFF files. TIFF, or Tagged Image File Format, is a standard file type for bitmap, or raster, data. Unlike JPEGs, TIFFs are not subject to lossy compression or to only 8 bits of color information. The file sizes are large; a 16-bit TIFF file will be about three times the size of the same RAW file, because TIFF is saved to 16 bits rather than the 12 or 14 bits recorded by the camera. The extra bit depth is an advantage over JPEG, but the same control issues that JPEG suffers from are present in TIFF capture as well. Color balance, sharpening, and noise reduction are all applied directly to the image at the time of capture. The only advantage that TIFF offers over JPEGs is color fidelity and lossless compression. To be honest, I can’t think of a single instance where saving a TIFF file in camera is a good option.
When RAW isn’t the Best Choice: There are times when the extra work involved with RAW processing can’t be justified. As an example, photojournalists will typically shoot in JPEG when shooting for assignments. The image files are smaller, important for quick transfer to the newsroom, and the JPEGs can be used with little or no extra work before publishing. Another time when JPEGs may be a better choice is when you are shooting youth sports events and want to make prints for sale right at the site. This is another case of speed being more important than quality.
I love to share information on digital imaging and photography, and I hope my new book reflects this passion. I’d love to hear from you with comments about Adobe Camera Raw or to share your experiences.
