Video turns grey when I try to record it using Quicktime

I am trying to save chapters of a DVD as movie files so I can share them online (this is a DVD of home movies essentially, so there shouldn't be any copying issues). I have been trying to save the videos using Quicktime's screen recording features, but whenever I click record and have selected the area where the video is playing the video turns to a grey screen. I can still hear the audio playing, but the image remains a grey box until I stop recording. Any suggestions?

If, as you say, the DVD in unencrypted, most people would simply open the content in the free HandBrake app and transcode the files, chapters, or timed segments directly to MPEG-4 or MPEG-4 AVC video with AAC and/or AC3 audio for sharing as MP4 or M4V files.

Interesting... is this easy to figure out?

That would likely depend on what you want to do.

The simplest approach would be to open the app and navigate to the VIDEO_TS folder on your DVD (or HDD if you already copied the folder to your system). Next select the specific "Title" you wish to transcode if there are more than one on your DVD. Since you indicated you wanted to share "chapter" segments from your DVD, you would then select the "start" and "Through" chapters to be included. (E.g., if you want to share Chapter 5 on Title 1 of your DVD, then select Title 1 in the "Title" pop-up, Chapter 5 in the Chapter Start pop-up, and Chapter 5 in the "Chapter Through" pop-up.) Next, you press the "Toggle Presets" button to open and select a target "Device" or "Regular" preset option as needed. Add the job to your queue window. When all jobs are queued or if you are only processing a single job, press the "Start" icon to initiate processing of your content.

You can, of course, create and save custom user presets but that implies you know how to use the various tab window options for best encoding results. This app is very powerful but can be used by anyone from a novice just starting out to an experienced pro depending on their level of expertise. If you can access your source content sequentially (i.e., copied to an HDD or have multiple DVD players loaded), you can use it to "Batch Process" multiple VIDEO_TS folders in a single session while you engage in other activities like sleeping or working.

Any specific questions regarding use not covered by the site manual (see Help menu in app)?

Not sure but I think anything that plays through the DVD Player app will be blocked from recording.