Hands on: How to take Windows screengrabs

It will come as no surprise that I spend a lot of time making screengrabs, but I’m not alone. For teachers, software developers, bloggers and anyone with a technical support issue, a screengrab is usually worth, if not a thousand words, at least several sentences of description.

There’s more than one way to make a screengrab. The PrtScr (Print Screen) key, a relic from the time of MS-Dos, is OK for some things, but what if you don’t want the whole screen or you need to see the cursor? Even if PrtScr gives you exactly what you want, you still need to paste the file from the clipboard into an application if you want it saved as a file.

Here I’ll show you how to make screengrabs, capture a sequence of screen actions as a movie and how to overcome a common problem, including movie playback in a screengrab. There are loads of screengrab utilities and you may well have a favourite: mine is Techsmith’s Snagit. I’ve used it for PCW screengrabs in this column for many years, so aside from Windows’ built-in utilities, that’s mainly what I’ll be talking about here.

I’ve also recently discovered another Techsmith product for capturing screen movies ­ – Camtasia Studio 5. In the past, my efforts to produce video tutorials have involved the use of screen capture, audio recording and video-editing software. As I recently had to produce some video tutorials for a website, I gave Camtasia a try and was pleased with the results. I’ve commented on what I think are some of this application’s best features at the end of this column.

Windows screengrab basics
The PrtScr key copies the contents of your video Ram to the clipboard. As I said earlier, one of the major drawbacks of PrtScr is that in most circumstances, it doesn’t display the cursor. It also copies the whole screen. But if you hold down the Alt Key while pressing PrtScr, only the active window is captured to the clipboard, which can be useful for capturing dialogue boxes and the like.

Windows Vista includes a Snipping Tool you can use to capture the entire screen, selected windows and rectangular and freehand selections. You’ll find it on your Start menu in Programs, Accessories. When the Snipping tool is active, Ctrl & PrtScr starts the capture process. A preview window with some crude drawing tools shows the captured area, which you can save as a PNG, GIF, JPEG or HTML page.

Snagit
There are many screen-capture utilities, but not all are created equal and some do little more than PrtScr. For many years I’ve used Techsmith’s Snagit.

Earlier versions of Snagit had a three-tab panel interface that organised grabbing into Capture, Edit and Organize. I only ever made use of Capture, as the other features are better catered for by other applications. However, in the new version 9 of Snagit, the editing and organising functions have been hived off to a separate Editor application.

Snagit allows you to define capture profiles and includes some useful presets, such as Full screen capture, Window capture and Object capture. The preset profiles make a good starting point for creating your own. The default hotkey is PrtScr, but this can be changed in the preferences.

There are four capture modes: Image, Text, Video and Web. Image is the one I use most often and produces a conventional screengrab. I’ve found the video capabilities of Snagit too limited and the quality of the results insufficient for producing video tutorials, but for a short clip lasting a few seconds, it’s usable.

There’s also a text option that captures readable text (not a bitmap) from the screen. This is particularly useful if you want to copy text that can’t ordinarily be selected, such as your recent documents list, the contents of a menu or an inscrutable error message. The final option, Web, trawls a web page, copies all graphic files and saves them to a folder.

Snagit’s Input menu defines exactly what you want to grab and includes ­ but extends far beyond ­ the whole screen and active window options of PrtScr. You can define a region with a rectangular marquee, set a fixed region (useful for recording one screen of a dual-screen setup), capture menus and other objects, and define an irregular screen region with a lasso tool.

Scrolling options allow you to capture the entire contents of a scrollable window so you can, for example, create a very long or wide screengrab of a spreadsheet or a long web page.

There are multiple output options; among other things, you can open the grabbed image in your image editor, print it directly, attach it to an email or FTP it. The most useful option and the one I use almost exclusively is to save it to a file. In this case, you can choose a filename or have Snagit automatically apply sequentially numbered ones ­ for example, Step 1, Step 2 and so on.

You can also apply all kinds of effects to the captured screen image, including edge effects and watermarks. More usefully, you can downsample the capture, reduce the colour depth or automatically trim screengrabs. Being able to perform these operations automatically during capture saves both time and effort.

Options buttons allow you to toggle settings such as displaying the cursor, capture preview and multiple capture. This last one is useful for capturing, for example, a menu bar complete with selected menu and sub-menu, and is the kind of thing that would take an age using PrtScr.

One of the problems I always used to have with screengrabs was capturing tooltip windows and other elements that have a tendency to disappear when you press a key. Snagit allows you to incorporate a predefined delay so you can avoid this, and it will even display a countdown so you can get everything set up in good time.

Delayed capture is also useful for capturing processes such as scripts that would be interrupted by keyboard input. You can also use this feature to perform scheduled captures.

Grabbing video
Taking screengrabs that involve video ­ for example, a software DVD player or video-editing application ­ can sometimes be problematic. Where the video frame should be displayed, all you’ll see is a black or green box. This happens because of the way video applications write to the display to improve performance.

They use a dedicated screen buffer in video hardware to render the video frames, which are then overlaid on the display using chromakey. PrtScr and screengrab utilities can’t read the hardware overlay, so all you see is the chromakey rectangle that indicates the position of the video.

However, there’s an easy way around this ­ turn off the hardware overlay to make your screengrab, then turn it back on when you’re done. In Vista, right-click the desktop, select Personalize and click Display Settings.

Click on the Advanced Settings button, and then select the Troubleshoot tab, followed by the Change settings button. Next, drag the Hardware acceleration slider all the way to the left towards None. The process is almost exactly the same in Windows XP.

Making video screengrabs
If you want to record a sequence of actions as displayed on your screen to make a movie, you’ll find that many applications designed to capture a single shot can also do movies. But while these are OK for short sequences, you’ll need something a little more heavy-duty for producing either software demos or video tutorials.

For the past few weeks I’ve been using Camtasia Studio 5. Making video tutorials isn’t something I do on a regular basis, but there are a few Camtasia features that can help you get a more professional end result, without having to spend hours using a video-editing application.

Camtasia allows you to define the area of the screen to be recorded and Techsmith’s Screen Capture codec ensures that menu text is readable, even when the video output size is smaller than the original screen resolution. Camtasia lets you record a voiceover either while you make the screen capture, or during subsequent playback.

You can also pause the recording whenever you like and there’s a really helpful feature that inserts duplicate video frames if your voiceover segment is too long to be accommodated.

Best of all, though, is a tracking feature that automatically zooms in on cursor activity, so your viewers get close-up shots of menu selections, tool applications and the like. All of this is keyframed on the video timeline so you can edit or remove it if it’s not what you want. At $299 (about £150) it isn’t in the budget category, but you can download a free fully functional, 30-day trial here. PCW

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