[Tig] Oxberry scanners

Jason Crump jasoncrump at gmail.com
Wed Nov 29 08:34:08 GMT 2006


Hi Chris,

Regretfully, we did not output the frames as a continuation of the test.
That same shot was recorded as part of an ad film that was fully scanned on
the oxberry. This was of course graded.

I fully understand the the importance of a "closed loop" setup. However, i
see this as imperative for setups where one is not grading what is being
scanned. For example, scan->VFX->record. But generally, i don't think giving
raw scans to VFX is an advisable process. I think the closed loop between
the grading room-->recorder-->film print is far more important. If your
grading environment is set up so that WYSIWYG then why sacrifice the
potential of the space we have avialable on a 10bit log scan? Breaking
cineon guidelines on the scan may open a can of worms....but in a controlled
set-up i believe there are many benefits that can be had...anyways, I like
worms in my garden. ;) Ok, there is also the argument that a DOP wants the
scan to exactly represent what he/she has shot. But i would say to that...
most labs do a similar thing while grading the OCN to the IP-->DN-->print.
We want an optimum exposure on that IP/DN and will finally print down or up
on the print to achieve the desired result.

Chris Swinbanks wrote:
>Sticking pretty close to the old Cineon dynamic range will always give you
you're best bet >at outputting at most noteworthy facilities around the
world and getting an acceptable >result.
...
>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).

I totally agree with this. But i am not asking that we change the recorder.
(although Cinesite touches on the potential benifits of this by recording
what they call a "heavy negative.") I am only suggesting , (in a  controlled
setup), that it might be beneficial to utilize the entire range available in
10bit log while scanning. We can think of it much the same way a DOP might
over-expose his/her OCN in an effort to get pretty pictures. Despite the
guidelines that Kodak has, they are optimizing potential in a controlled
setup. Ask most film timers and they will always tell that pictures look
nicer if printer lights are in the 30's versus in the 20's. But yes, finally
I am grading to fit whatever range i have received on the scan into a
recorder that is set for 10 bit cineon.

Chris Swinbanks wrote:
>The manufacturers only give you the tools to get the job done, to various
levels of >competency.

Unfortunately, manufacturers don't "give" us anything. ;) We have to spend
hard earned money to try to get what we want. For example at the last
facility i was grading at, i wanted to expand the dynamic range of the
scanner. To get this option, a costly additional hardware LUT card had to be
purchased. And I am not even sure as to whether that card simply remapped
the scanned code values the same way an input LUT would or whether it
changed the LUT from the analog sensor to the digital value. This is the
type of control i really want. It seems in theory this should actually not
be so hard to implement...we just need the controls to do so. Is this too
much to ask? ...manufacturers? Are any already offering these facilities? We
can all always remap code values from one to another with an input LUT, but
this does not actually improve scan quality and does not optimize the
potential of the sensor.

The standard scan LUT's that all of the scanners we looked at seemed to use
(except oxberry) definitely would not have shown a closed loop system. I can
say that they would have all fallen under-exposed. Blacks seemed correct,
whites also seemed correct... it was how the mid-tones were distributed
between 95 and 685 that seemed under. Again, we did not scan wedges to
confirm this. These are only my observations. I also think that by turning
on any concealment tools while scanning, greatly disrupts whatever scan LUT
is being used...mid-tones drop.

Can any of the manufacturers or scan/record experts touch on some of the
questions i have posed here and before?

best,

jason
colorist
mumbai



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