In the meantime I had a conversation with Juha, and he could confirm, that RAW + aspect ratios on the Panasonic LX-5 work exactly as I had hoped. Worst case would have been a system where the RAW file always records the whole sensor, i.e. where the different aspect ratios would only have an influence on JPEG files and you would have to crop when working from RAW. The best case, otoh, would be a system where you get different RAW files for different aspect ratios and everything just works.
Well, fact is, everything just works, it’s exactly as Juha has said. Not that I had doubted 🙂
The Image of the Day is, well … not much of an image, but it was taken with my new Panasonic LX-5, converted from Panasonic’s proprietary CR2 format to DNG with Adobe’s DNG converter, and then converted from RAW with Photoshop CS3’s Adobe Camera RAW 4.6. Works like a charm 🙂