Cinematography Mailing List

The following is from Alfonso Parra - January 2007

I have recorded with the camera Genesis a Macbeth colour chart and a Kodak greys scale with the camera to 24psf 172.8 ECS and the curve Panalog 4, Matrix off, sat off and filter pre-set to 3200 K, recording in RGB 4:4:4 SQ, with the nominal sensibility indicated by Panavision Spain of 400ASA.

We used a 50mm Primo lens .

Images was captured in Fotofilm/Deluxe with a Sony SRW 5500 in RGB, dual link 4:4:4 with a DVS Clipster, entrance format RGB, dual link 4:4:4. The video images are turned into real time to data, format DPX 10 bits

. Really there is great information in half tones and high lights with the curve Panalog 4.

But our surprise has been in underexposures where we have observed than with almost 1 1/2 stop of underexposure there aren’t too much shadow details, although blacks are consistent and with not much noise. In reality, as we could check with panavision information, the curve Panalog4 is not really log , Camera convert 14 lineal bit into a 10 bit log with a pseudo log curve . In this curve grey 18% have a low value and an there is not much information on shadows, that it is what we see in the display, and however Panavision indicates that you have more shadows information than any other linear system. The impression is that the referential value for the exposition is not the grey 18 % ( 382 ) but other superior ( 680 ) ,If we use this referential value and applying the lut of correction, there is more information in blacks (4 stops) but also less in high lights(3 stops).

Please click on any frame to download the original DPX