M9 anyone use DNG uncompressed?

[percepts]

Now I am surprised that it's really a lossy compression. That's not what I expect when I hear DNG or Digital Negative.

But the compression is not adobe compression. It's leica compression. Infact that is the wrong word for it as there is no uncompress function for it. It is a colour depth reduction which results in a smaller file to convert to DNG format for output from the camera.

 

[user237428934]

But the compression is not adobe compression. It's leica compression. Infact that is the wrong word for it as there is no uncompress function for it. It is a colour depth reduction which results in a smaller file to convert to DNG format for output from the camera.

Like a compression for audio signals I suppose. Cut away the frequencies a normal listener does not hear anyway

 

[percepts]

Like a compression for audio signals I suppose. Cut away the frequencies a normal listener does not hear anyway

Well in image file processing its more like converting from Adobe RGB to sRGB except from what Jaapv says it is more sophisticated. i.e. you are getting a smaller colour gamut which effectively means you are getting clipping from what the camera is really capable of. Hence my original point. i.e. since most print output uses sRGB is there any point in using uncompressed. The answer seems to be that uncompressed is worth it for optimum post processing before setting to output colour profile.

 

[jamato8]

Like a compression for audio signals I suppose. Cut away the frequencies a normal listener does not hear anyway

Yes but as you get into higher end audio, there is a sound difference, as there may be as you get further into the processing of an image. I work with 3 electronic companies in the high end audio world, doing design and beta testing. For many, in audio, lossy works but when truly high end is implemented and the micro and macro dynamics and impression of space and transparency are made all the more relevant, so is the realism. The same may be happening here with "compressed" and "uncompressed".

 

[jaapv]

I thought that the uncompressed format was 12 bit while the compressed was 8 bit (like the M8)?

From the M9 technical data on the website:
"DNG™ (raw data), choice of uncompressed or slightly compressed (by non-linear reduction of color depth)"

From the manual:
"The Compressed format includes a slight compression,
which
– causes only a negligible deterioration in quality
– provides full scope for subsequent processing of
the picture data
– allows faster saving
– takes up less memory space."

No, compressed is 8-bits which masquerades as 12 bits, uncompressed is 16 bits, which of course boiles down to 14 bits like any 16 bits file.

 

[jaapv]

Well in image file processing its more like converting from Adobe RGB to sRGB except from what Jaapv says it is more sophisticated. i.e. you are getting a smaller colour gamut which effectively means you are getting clipping from what the camera is really capable of. Hence my original point. i.e. since most print output uses sRGB is there any point in using uncompressed. The answer seems to be that uncompressed is worth it for optimum post processing before setting to output colour profile.

That is well put. Of course you have to come down in gamut when you have finished proicessing the file; there is no printer that does better than aRGB, although some professional ones accept 16 bits, and the web is 8-bits sRGB all the way. But when postprocessing the file it pays to have all the data you can get.

 

[snaggs]

Just wondering if using DNG uncompressed affects performance at all? Infact I'm wodering whether there is any perceivable difference between uncompressed and compressed as all that the specs seem to be saying is that colour depth is reduced and most output devices only use sRGB anyway.

Shooting uncompressed, bought a 32gb Sandisk card, and I delete my crap shots once I import them.

Daniel.