Jump to content




Photo

Even cameras that do not shoot RAW use a BAYER pattern (or another color filter mosaic)?

RAW bayer color filter array

  • Please log in to reply
9 replies to this topic

#1 davide sorasio

davide sorasio
  • Basic Members
  • PipPip
  • 89 posts
  • Student
  • New York

Posted 05 January 2016 - 12:00 PM

Hi everybody, I'm reading David Stump's digital cinematography manual and I need a couple of clarification. Is BAYER FILTER ARRAY (or any other color filter mosaic) used in both RAW or RGB signal output cameras? And does it have something to do with it or that's just a way that the sensor read the lights and it's independent from the file format? It's kind of confusing to me because I wonder if the Bayer CFA is used only when shooting raw or if it's just a system that is independent from the FILE FORMAT.

Thanks in advance for the help!


  • 0




#2 Tyler Purcell

Tyler Purcell
  • Sustaining Members
  • 2366 posts
  • Other
  • Los Angeles

Posted 05 January 2016 - 12:18 PM

The Bayer pattern is always there, but it's executed differently with RAW.

http://www.adobe.com...lrawcapture.pdf
  • 0

#3 Adrian Sierkowski

Adrian Sierkowski
  • Sustaining Members
  • 6771 posts
  • Cinematographer
  • Los Angeles, Ca

Posted 05 January 2016 - 01:03 PM

Bayer is a part of, as far as I know, EVERY single chip imager-- e.g. pretty much every camera made these days, stills and video. It's a way to derive 3 colors from a single chip which has essentially monochrome photosites.

As such it doesn't matter at all if it's raw or not. My cellphone is a bayer-ed CMOS (though you could have a bayer CCD as well).

The only real difference is with Raw, you don't record debayered data-- that is saved for later on, normally done quickly for editorial and then very slowly when you get to your conform stage.


  • 0

#4 dan kessler

dan kessler
  • Basic Members
  • PipPipPip
  • 158 posts
  • Other

Posted 05 January 2016 - 07:15 PM

Don't want to delve too far into something at which I'm no expert,
but there is one variant that does not have a Bayer pattern.
The foveon chip, which is utilized in Sigma digital cameras, is an RGB
design whose construction is similar to film itself.  It is a layered
arrangement with no offset.  It delivers stunning images with absolutely
none of the artifacts associated with the Bayer pattern.

 

I often wonder why it hasn't made a bigger splash.   They don't seem to

market it very aggressively.
 


Edited by dan kessler, 05 January 2016 - 07:22 PM.

  • 0

#5 Tyler Purcell

Tyler Purcell
  • Sustaining Members
  • 2366 posts
  • Other
  • Los Angeles

Posted 05 January 2016 - 09:51 PM

DALSA's imagers didn't have Bayer either.
  • 0

#6 Phil Rhodes

Phil Rhodes
  • Sustaining Members
  • 11232 posts
  • Other

Posted 06 January 2016 - 04:01 AM

I think they did, at least the one in the Origin did.

 

Other things have been tried. The chips used in the F35 (and thus Genesis) had vertical stripes of red, green and blue. There are various workable approaches, with various upsides and downsides.

 

The difference with (various riffs on) raw is that the process of recovering a normal RGB image from the sensor data isn't done in camera, or at least the version that's done in camera is just for viewfinding and isn't final.

 

The problem this creates is that every camera manufacturer likes to claim that their process is clever and special and different to everyone else's, which largely isn't necessary, and it creates a lot of compatibility issues and general headaches in post.

 

P


  • 0

#7 Kyryll Sobolev

Kyryll Sobolev
  • Basic Members
  • PipPip
  • 23 posts
  • Camera Operator
  • Toronto

Posted 06 January 2016 - 02:38 PM

Phil, maybe you can help me understand this better, but from my reading I understood that 2/3 of the colour information is essentially "made up" by the chip (extrapolated if you will)

 

is that wrong way of thinking about it?


  • 0

#8 Phil Rhodes

Phil Rhodes
  • Sustaining Members
  • 11232 posts
  • Other

Posted 06 January 2016 - 03:35 PM

No, that's quite correct.

 

This is why people tend to question whether cameras with 4096-pixel-wide Bayer sensors are really 4K.

 

P


  • 0

#9 Adrian Sierkowski

Adrian Sierkowski
  • Sustaining Members
  • 6771 posts
  • Cinematographer
  • Los Angeles, Ca

Posted 06 January 2016 - 04:44 PM

And that's not even getting into anything like the Nyqist limit and the whole notion of MTF--- however that's too deep i find. Effectively, let's say a 4K Bayer resolves about 80% of what it samples and in almost every case, the difference is so academic as to not be an issue in a real world situation.


  • 0

#10 Phil Rhodes

Phil Rhodes
  • Sustaining Members
  • 11232 posts
  • Other

Posted 06 January 2016 - 06:11 PM

about 80% of what it samples

 

On relatively unsaturated subjects, yes.

 

On more saturated subjects, it can be considerably worse, depending what compromises of sensitivity, resolution and aliasing the manufacturer has wrought.


  • 0



Also tagged with one or more of these keywords: RAW, bayer, color filter array

The Slider

Rig Wheels Passport

Aerial Filmworks

Ritter Battery

Zylight

CineLab

Abel Cine

Paralinx LLC

Broadcast Solutions Inc

Glidecam

Pro 8mm

Tai Audio

Visual Products

CineTape

rebotnix Technologies

Technodolly

Willys Widgets

Pro 8mm

Visual Products

Willys Widgets

rebotnix Technologies

Technodolly

Glidecam

Tai Audio

Ritter Battery

Paralinx LLC

CineTape

Aerial Filmworks

Broadcast Solutions Inc

The Slider

Zylight

CineLab

Abel Cine

Rig Wheels Passport