[Konvas] color correction in post (was: first test time lapse ... with 7D)

[colcam at aim.com]

 I was treated to a three day "this is what we are going to" class, and what sounds strange is that the best 4k projection is based on "printed" standards because the image is a mirror reflection image, and that's where the "positive versus negative" factors start to play.  When you go to creating an image that is then reflected and projected "how bright" is the first factor for an RGB color, while there is no "brightness" to the CMYK color-- it is defined as a color.

The next generation is based on an S image, one where only the pixels changed are changed, not a progressive redefined picture, but, like the new flat panel computer screens, it refreshes the whole thing 600hz and only changes the pixels that need to be changed.  That may be none, that might be all of them. 

As you noted in your followup, the way the colors are defined makes things interesting.  The RGB has a block of "one color" that is shaded by brightness to take the place of ten steps or a hundred steps, and both the capture and display limit it, while the CMYK version has no brightness-- every color is defined as a color, and that is what it reflects. 

Mix equal amounts of R G and B and you get white, so no R, no G, no B, you get black.  CMYK mixes colors to create the R, for example, but has to add black to create black, because it has to overprint the colors or replace the CMY factors. 

In a nutshell, one starts by beating your head against the wall and crying.

 


 

 

-----Original Message-----
From: Adam Frey <thefirstrule at chainsawlinux.com>


On Mar 11, 2010, at 1:29 PM, colcam at aim.com wrote: 
> One of the "quiet revolutions" being made is the way color is > handled-- it was "amount based RGB" with about 4000 colors-- it is > going to indexed CMYK with over sixteen million colors. 
 
I recently ran into an issue for a client's project, importing a TIFF into a PPro timeline. It had apparently been converted to CMYK. After messing with it for too long (and trying to export Jpeg's that were a negative of the original file), one of the graphic designers came by and figured it out in about 5 seconds (she sent me a new TIFF in RGB a few minutes later that worked just fine). So I decided to learn a little about CMYK from that whole process. 
 
I know CMYK and RGB are completely different - and to convert from one to the other, you're probably going to have some form of generation loss. But isn't CMYK for printing? Partially so the printer can save it's pricier colored ink over the less expensive black ink, but also because it's being printed onto a paper that absorbs inks vs projected with light? 
 
While we're on the topic, talking about RGB bits is a pain, since 24-bit is really just 8-bit multiplied by the 3 color channels, and 48-bit is 16-bit also multiplied by the 3 color channels. But even those numbers don't even remotely add up to the 16 million colors your talking about (8-bit is 2^8 = 256. 16-bit is 2^16 = 65536). 
 
Adam Frey