Achei agora um artigo aqui, e pelo que entendi é importante o uso controlado do DNG, são 3 tipos, de DNG,
http://dpbestflow.org/DNG#when-convertThree types of DNG files
There are, broadly speaking, three types of DNG files, in-camera, converted DNG, raw; and converted DNG, linear.
In-camera DNG – Some camera manufacturers have adopted the DNG format as their own camera raw format. When you shoot a raw file with a Leica M9, it will be DNG. The Pentax K5 offers the option of shooting in PEF raw or DNG raw. 
FIGURE 2 Some cameras can produce a DNG as their native format.
Converted DNG, raw – When you make a DNG from a raw file, you typically have the option to save the original raw image data as is, in all its rawness. These files have all the image information that the camera wrote into the original raw file. There is one camera sensor that is not supported as a converted raw DNG, and that is the Foveon sensor used in Sigma cameras. This is a fundamentally different type of raw image data than other DSLR cameras use. To save a Foveon raw file as DNG, the file must be saved as a Linear DNG.
FIGURE 3 It’s possible to convert a raw file to DNG and retain all the rawness.
Converted DNG, linear – It’s also possible to save a DNG with some of the rawness processed out of the file. This is called a Linear DNG. These can be useful for enhanced compatibility. It’s also possible to convert a JPEG or TIFF to DNG, and that will produce a Linear DNG file. 

FIGURE 4 A Linear DNG has some of the image decoding “baked-in”. DNGs made from TIFF or JPEG originals are also Linear.