Willy ha ragione solo se si parla di rec lineari appunto.
Ma non sembra proprio che sia così, anche coi DNG.
Ad es per la BM parlano di LOG cinemaDNG ancora dalla vecchia pocket:
http://postperspective.com/12-bit-log-c ... ma-camera/Per la Arri, anche lì sono 12bit ma LOG.
Per la Canon, idem, c'è il LOG Canon Cinema RAW .RMF
Come spiega questo interessante articolo:
http://m.learn.usa.canon.com/resources/ ... raw.mshtml"Arri Alexa does record uncompressed RAW, but it does so in 12-bit Log format, not in RAW uncompressed 16-bit Linear"
"one of the key elements to the Canon Cinema RAW process is the gamma mapping or tonal mapping from a high bit depth linear image to a 10-bit Canon Log encoded image
[...] The question is then: "Why is this applied to the RAW signal and not left to the post-production realm?
In order for a sensor to achieve really good dynamic range representation, the data that it perceives must be recorded at very high bit depths
[...] By applying this gamma transform, you are able to efficiently store the usable information provided by the sensor in a more economical container without any visually perceptible loss of data. That is the genesis behind the Canon Log implementation: take all the high bit depth linear sensor data from Canon's Super 35mm image sensor and remap it into a more efficient and economical 10-bit Log container without losing any highlight or shadow information in the process is the genesis behind the Canon Log implementation.
[...] this nonlinear transformation of the linear sensor data. "
In sostanza il RAW viene definita la registrazione dei dati del sensore senza debayering o altre elaborazioni, MA non necessariamente dati lineari, si può applicare una curva gamma prima.
RAW is: "being in or nearly in the natural state: not processed."
E anche il DNG può farlo. Quindi il BM DNG non è lineare, quindi riesce a registrare più di 12 stop.