I have been flying two P4´s now for a few months. Harddisks are filled with lots of data. Checking the DNG-filesize; they are quite large compared to size of sensor in P4 (12MPix), filesize is 24MB.   So there is no lossless compression on Phantom?  Anyone know is it possible to compress (lossless) them afterwards; just to save space...

Hello Perti, currently there isn't an official compression tool. Maybe a new 3TB HDD would be a good choice

This is a puzzling question, since the whole idea of DNG files is to have no compression and no un-necessary processing applied to the files. If you want smaller files, use the JPEG mode. If you used any form of lossless compression, applications such as Photoshop and Lightroom would not know how to open them.

However, having said that, Adobe have a free DNG convertor that produces somewhat smaller files from the originals, try that.

DJI-Paladin Posted at 2016-8-16 09:50
Hello Perti, currently there isn't an official compression tool. Maybe a new 3TB HDD would be a good ...

Maybe    But how about providing real raw-file instead of Adobe´s DNG?  

petri.puurunen Posted at 2016-8-16 17:12
Maybe    But how about providing real raw-file instead of Adobe´s DNG?

Not sure how much that would help, would a 'real' RAW file be much smaller?

DrawsWithLight. Posted at 2016-8-17 14:44
Not sure how much that would help, would a 'real' RAW file be much smaller?

Yes it is. Camera´s sensor is 12Mpix and DNG is 24MB. And usually camera-raw (On Canon, Nikon, Panasonic, Sony...) is compressed. Estimated size is somewhere between 14 to 20MB.

Well on the latest Sony camera, uncompressed RAW weighs in at 85MB vs 41MB compressed.
Even jpeg from such large sensors weigh in at 11MB+
RAW has always been big in my experience