iMac won't recognise .MTS videos on my hard drive, how can I play them? We just purchased an iMac yesterday to view our travel videos. The thing is, all the videos we have stored on our external Hard Drive are in the .MTS file format (AVCHD). The thing is, the Mac or QuickTime won't recognize them. Are there any good / free file converters so we can convert the video files to .MOV as that seems to be the common file format for Macs.

I read on-line that you can fool your computer into thinking that it is reading the video file straight from the Camcorder instead of from an external Hard Drive but you have to reorganize the storage or hierarchy of the videos. Apparently this can take up a lot of memory though - maybe up to 10 times the size of the original video file size? Is it a viable solution?

What's the best / most straight-forward / preferably free way to get the videos into a usable format?
Try VideoLan. It is free and should handle most kinds of video formats.

The method for recognising AVCHD format is with regard to Apple Video applications, and not QuickTime. Those applications have the reader for that format. But you're only interested in viewing them so I suggested VideoLan.

Also there is a QuickTime plugin which recognises many formats, but I have never tried it with AVCHD or MTS formats. It is called Perian. Please note that it is no longer supported in the form of updates but it is still offered on the official site.