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RE: TK Transfer v Compensated Conversion



Motion compensated conversion technology does not work on film 
originated material.  This type of converter was specifically designed
to convert video originated material, where it looks to each field to have
its own motion.  Film originated material transferred to video lacks the 
consistent field by field motion required by the motion compensator.  
When the converter detects a lack of field sequential motion it will 
invariably revert back to temporal interpolation (judder and smearing).

What you need to do is look into conversion technology which is
designed for film originated material.  This type of converter will add
a 3:2 pulldown to your PAL originated material while at the same time
it will perform spatial interpolation in order to create 525 lines from the 
625 found on the PAL master.  

As for apologizing, don't bother!  We have performed many of these 
transfers over the years and I can tell you that the finished 525 
conversion is indistinguishable from a direct telecine to 525.  An added 
benefit is realized via the spatial (line) interpolation in that it acts as an 
anti-aliasing filter, countering the effects of interlace.  A much
"quieter" picture is the net result.

The program length and pitch issues are no different than if you were
to perform two telecines, one to 525 and one to 625.

Jeff Dewolde
International Image
Santa Monica



-----Original Message-----
From:	Jon Walley [SMTP:jonw at tvp.co.uk]
Sent:	Wednesday, August 13, 1997 1:48 AM
To:	'Telecine Internet Group'
Subject:	TK Transfer v Compensated Conversion

At the risk of stirring up a hornet's nest, I would like opinions on the
following scenario:

A client has asked me whether to save money they can TK in 625 onto
DigBeta and then use a motion compensated converter with shot detection
correction to make a 525 converted master on DigBeta

Ahh! Sharp intake of breath from the TIG.  But wait - this very grainy
print needs considerable electronic noise reduction to be acceptable to
meet the distributor's requirements and therefore the effective
information bandwidth has already been compromised. 

This converter is regularly used for converting large budget commercials
with the entire production team enthusastic about the results ( many
cannot distinguish between before and after, the results are so good.)

This process is only being considered for  625 to 525 and I am aware of
audio pitch and duration considerations. Please bear this in mind.

Jon




++thanks to Digital Vision USA for support of the TIG in 1997
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