The MPAA and most media companies argue that you can’t legally copy or convert commercial DVDs for any reason. I (and others) think that, if you own a DVD, you should be able to override its copy protection to make a backup copy or to convert its content for viewing on other devices. Currently, the law isn’t entirely clear one way or the other. So my advice is: If you don’t own it, don’t do it. If you do own it, think before you rip.However,making copies of home made DVDs is totally legal.

Picture this scenario: you go to retrieve your DVD copy of Willy Wonka & the Chocolate Factory from its protective case because your son or daughter wants to watch it for the 437th time. You remove the DVD only to find it scratched and just a little bit sticky from the jam-covered fingers that last handled it. Sound familiar ?

In the past, I used some application such as HandBrake to rip DVDs to watch on an iPhone or Apple TV, and covered some of the frequently asked questions about DVD ripping. But what if you want to make an exact copy of a physical DVD to use as your ‘viewing’ disc and keep the original safely on the shelf? Or how about if you’ve received (or created) a DVD of home movies or a wedding and want to duplicate it for family members. Here’s what you need to know.

If you want to make copies of that DVD your cousin sent you of her son’s bar mitzvah (or any other unprotected DVD), the process is relatively simple. Insert the DVD into your Mac’s optical drive and launch OS X’s built-in Disk Utility app (found in the Applications/Utilities).

Click the New Image button at the top, select the DVD in the dialog box that appears, and in the Image Format pop-up menu choose DVD/CD Master. Pick a name and destination, and click Save. After a while, you’ll have an image file with a .cdr extension. That disc image contains an exact copy of your DVD, which you can backup on an external hard drive for later use.

To burn that image as a DVD that you can watch in a standard DVD player, launch Disk Utility and you should see the image listed on the lefthand side. If so, click the image name, and then click the Burn button at the top. If you don’t see it listed, click the Burn button first, then navigate to the image’s location, select it, and click Burn.

In either case, Disk Utility will then prompt you to insert a blank DVD (if the original was a dual-layer DVD, you’ll need a dual-layer blank DVD for it to work). If you want to adjust any of the options (including what Disk Utility should do when it’s done burning) click the blue triangle button to expose those options. When you’re set, click the Burn button. When it’s done, the disc should play on your computer on set-top DVD player. (A note on DVD media: I’ve found DVD-R discs to work well for single layer movies, and DVD+R good for dual-layer movies, when it comes to DVD player compatibility. But it’s always best to test your burned DVD afterwards to make sure it plays as expected.)