There are several ways to capture a scene from a DVD. Ripping DVD's (i.e. copying the entire contents of the DVD directly to the computer) is in most cases illegal. This is because even if you own the DVD (and you legally own the contents of the DVD), you end up breaking copy encryption codes when you directly rip DVD's to your Mac or PC.
One of the legal ways to "capture" copy protected DVD's is by using an analog device like a DV player. Capturing a DVD is different from copying a DVD since capturing does not involve breaking the copy protection present in DVD's. What basically happens is an analog device (like a handycam or a DV player) is set up as an intermediary output and the PC saves this output.
The FITC (Faculty Instructional Technology Centre) as well as the MDS (Multimedia Development Studio) in the library have the necessary equipment to capture scenes.
Make sure that the DV player is opened and turned on. Now setup the rack (the tall object holding all the DVD/VHS players). Turn the rack on and then proceed to enter the input and output codes.
For PC users
Open Windows MovieMaker and then click on File→ Capture Video→ Enter File name and location → select video settings (default settings are recommended) → Make sure to select Capture Video Manually → A window like the one shown below will pop up and you will be able to capture the desired segment of the video
For Mac users
Open up iMovie or (Final Cut Express) and proceed to start copying the DVD. Click on the camera icon to bring up the recording window as shown below.
Setup the DVD to the start of the particular scene you wish to copy and then start copying, remember to press the done icon when you are finished.
Besides legally capturing video, people also resort to third party software that allows you to directly rip DVD's onto your computer. As mentioned before, copyright rules state that even if you own the DVD, ripping the DVD is illegal if you have to break encryption codes in order to do so. Except for homemade movies almost all commercially produced DVD's have some sort of encryption so as a rule ripping any DVD in the US is considered illegal.
If you require it though there are several free and paid software that will help you accomplish this: