For example, when I log onto the SDMB, I have to scroll down to see the BB Pit. What if I want to capture the whole front page from top to bottom, but the whole thing doesn’t fit on my screen? I’ve tried cmd+ctrl+shift+4, but when using that it won’t let me scroll down to capture the images that are not on the screen. Anyone?
You can ⌘-minus your way towards smallest browserfonts, which will cram more threads into that window. Or you can change your screen rez if it isn’t already at maximum.
You could scroll, take multiple screenshots, then stitch them together, either manually (wouldn’t be that hard given how regular-sized the images are), or using some Photo Stitching software.
Look for a browser extension. I don’t know anything about Macs but they exist on windows and linux. It might be called “full page” or “whole window” screen capture.
To expand on this answer, if you want to easily set it up as a keyboard shortcut, go to System Preferences > Keyboard > Shortcuts and click on “App Shortcuts” in the left window. Click the “+” to the right and in the “Menu Title” field, and type “Export as PDF…” without the quotes, but make sure to include the ellipsis. In the “Keyboard Shortcut” field, use a key combo that isn’t used by any other app, something like control-option-command-P. Close the System Preferences window, click on the web page you want, press control-option-command-P, save it to wherever you want the PDF saved, then open it.
Seconding this. I have an extension for Firefox that lets me capture an entire page as an image. Not in front of my desktop at the moment but I think it’s called Pagesaver.
The reason is that the screencapture feature is from the OS, and the OS doesn’t know if the scroll bar meaning is … the scroll bar may be more about showing and hiding than just having a virtual screen size.
If you want to capture two screen fulls, you could just capture two pictures…