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Re: Transfers, records and Repeatability.



Hello Steve,
> 	
> 	My question is this, when i take my negative to a telecine session, and then
> we set up the gray scale, and start correcting. Can the correction settings
> be saved? Can I shot something two weeks later, and walk into the telecine ses
> sion and say, I'd like to see The correction we did two weeks ago first (or
> bring a record of that correction with me), and then go from there? Can the
> individual sessions corrections be printed out, in terms of what correction
> for what footage.

A two week wait will not be a problem anywhere.  On a Rank, the CRT 
ages significantly over its lifespan.  Two weeks would not be a 
problem, but two months would show a noticeable difference.  For this 
reason, it is also necessary to return to the original transfer 
facility, as other facilities' tubes would be in random states of 
decay.  There are so many variables on a telecine - resistors, caps, 
transformers whose values drift over the lifetime of the device - 
that a complete and viable standard cannot readily be achieved.  
Printers are dealing with light bulbs while we have complex 
electronic circuits to control.

If you are concerned about longer-term repeatability, I suggest 
choosing a facility with a CCD telecine such as the Spirit.  CCDs do 
not drift over time as much as tubes and it is likely that their 
corrections will hold much longer.  Tube ageing is the most 
significant reason for corrections having errors over time.

Modern color correctors also offer global correction ability, in 
which a colorist may rebalance one scene to a still-stored image, and 
the same correction will be applied to the entire list.  This could 
quickly return a corrupted-by-time set of corrections to viable ones. 
 It is unlikely that using this method will result in a 100 per cent 
recovery of the original session.

> 	Is this what the calibration films that are coming out supposed to help
> accomplish? Or is it impossible to balance telecines to the same neutral day
> to day.

Yes, using these films regularly can help keep a telecine's day to 
day neutrality, but that neutrality is only valid for that period of 
adjustment.  Your old corrections are still losing their accuracy as 
the tube ages.  It's just that the operator is keeping the telecine 
adjusted for a standard as it is drifting away.

> 	I would really love to be able to see/have some kind of readout/printout.
> whatever, of the session. Just so I could have a better grasp of how the film
> is reacting to the Telecine, and Vice Versa.

I think the TOPSY had this!  Ah, progress...

Robert Lovejoy

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