I have a Panasonic LX-3 and want to save files as dngs that are compatible with ACR 4.6, and ideally earlier. I am aware that there's an issue with this trebling the file size, but saw on another thread that this was 'resolved' in Lightroom 2.4. However I've tried converting in Lightroom 2.6 and if I choose anything other that ACR 5.4 under compatibility the file size is trebled. If I choose 5.4 in ACR or Lightroom the file size is about the same. Is this an issue that will be resolved in a future update of ACR? Thanks.
No. ACR 4.6 does not support lens correction opcodes, so the only way to generate a 4.6 compatible DNG file from an LX3 is to demosaic it, which results in the size increase. Unless Adobe chose to significantly update ACR 4.6, which is very unlikely, this situation will persist.
Thanks, even though that's not what I wanted to hear!