[CinePaint] Looking for a feature useful to smooth timelapse, sequences - grading (Frank Peters)

>Message: 1
>Date: Tue, 21 Nov 2006 17:40:16 -0800
>From: "John Arrowwood" <[email protected]>
>Subject: [CinePaint] Looking for a feature useful to smooth timelapse
>	sequences
>To: cinepaint-users-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
>Message-ID:
>	<517fa6f10611211740pe4256d2v8fcc3d121f0ae862-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
>Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>All,
>
>I'm a photographer trying to do timelapse sequences, and I'm looking
>for a tool that might help me to get around the difficulty that arises
>under changing light conditions.  Flashes in the resulting movie are
>very difficult to deal with.
>
>I tried to write my own tool that took the average of the 10 (or more)
>frames before and after and then try to 'adjust' the current frame to
>get as close as possible to that target.  Unfortunately, I could never
>quite get the math right.
>
>I'm CERTAIN that there are already tools out there that do what it is
>I'm looking for.  But I don't know what it is called, so I don't know
>how to find them.
>
>Is CinePaint a tool that has the feature I'm looking for?
>If not, does anybody have any suggestions of a tool that does?
>Or, perhaps, can point me to the necessary math so that I can
>implement it myself?
>
>Thanks!
>

Frank,

I seriously doubt you will get a satisfactory result by trying to 
manipulate the drastically different frames within a sequence;  the 
gamma/exposure differences between image frames on digital, and I assume 
you ARE using digital and not film, will be too drastic to adjust 
because there simply is not enough latitude in the image data.

Rather than manipulate faulty data, you need to place the camera on 
manual control and avoid any automatic gain circuitry that will place 
the data outside of adjustable parameters for it to look smooth.  Of 
course, that requirement negates the automatic aspects of the camera and 
requires an operator to be there 24/7 unless you can interface with the 
exposure and gain control circuits and write a program to create a 
"digital flywheel" exposure program that places exposure in a sweet spot 
averaged from exposure conditions typical for each camera setup.

What you REALLY need to do, and I KNOW you won't want to hear this, is 
use a good 16mm or 35mm film camera with time lapse motor so you can 
have the 5  to 7 stops of latitude film offers without manipulation, NOT 
the 1 to 2 stops digital offers without automatic gain control.  The 
bulk of all high quality, time lapse footage is still shot on film for 
that very reason.

Sorry I couldn't be of more help...

Frank Wylie





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