[Tig] Oxberry scanners

Chris Swinbanks cws at al.com.au
Wed Nov 29 00:28:00 GMT 2006

A question, did you output each of the tests to film again?

Generically film recorders are based on utilising Cineon/DPX code values 
so that the circular relationship from o'neg to digital neg is 
maintained (dynamic range / contrast, colorimetry).
Breaking that by changing the dynamic range of scanned material as 
described here opens up a can of worms for down-the-line production 
Unless of course you're staying in a broadcast environment....


Jason Crump wrote:

> re: calibration/setup and density/code value relationship:
> By looking at the scans, I think i can assume that most of the 
> scanners were
> "setup" by sampling base and then incrementally assigning code values 
> based
> on the densities of the layers as per cineon.  This effectively meant 
> that
> all of the code values were between 95 and 685 with some specular 
> highlights
> jumping above 685. This was true for all expect the Oxberry. Oxberry 
> scans
> spread the same densities among a wider range of code values. So base was
> around 50 and the specular highlights were in the 900's and the mid-tones
> were much more spread out in between.
> I can only assume that the scans whose visible black of base showed code
> values roughly around 95, were as per cineon. However, since we did 
> not scan
> density steps from d-min to d-max on an OCN, I don't know whether the
> density values from d-min to d-max were properly assigned their
> corresponding code values as per cineon.
> snip

> Although the oxberry scan looked brighter than all the other scans, I 
> found
> that because the code values were more spread out, I had much more 
> color to
> play with and much more flexibility to push and pull these colors. I 
> don't
> know the exact sensor specifications of these machines, but it seemed 
> that
> from photon to code value, I liked the oxberry the best. Is it as per
> cineon?... I don't think so. Is that a bad thing, if the results offer 
> more
> flexibility and dynamic range?... nope. Is this the result of a custom 
> setup
> by the facility?... probably. Can it be achieved on the other 
> scanners?... i
> don't know.

Chris Swinbanks
Post Services
ph 02 9383 4860
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Animal Logic Film
Bldg 54 Fox Studios Australia, 38 Driver Ave,
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telephone: +61 2 9383 4800 fax: +61 2 9383 4801 cws at al.com.au


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