View Single Post
  #10  
Old 31st July 2018
MikeOxon MikeOxon is offline
Full member
 
Join Date: Nov 2017
Location: oxford
Posts: 600
Thanks: 61
Thanked 107 Times in 93 Posts
Likes: 63
Liked 246 Times in 153 Posts
Re: A Monochrom(e) Oly?

Quote:
Originally Posted by Ian View Post
............... I'd like to understand how a pure mono image would differ ...

Technically, there should be a small improvement in definition and tonal shading. The trouble with using a camera with a Beyer array for mono work is that various compromises are made in the algorithms that produce a colour image.



The Beyer array effectively contains a series of monochrome sensor cells, some of which are red filtered, some blue, and some green. Clever mathematics is then used to approximate the brightness and colour for each of the individual pixels in the final image, by combining information from each square block of four sensor cells that make up the Beyer pattern.



While this works very well in regions where the brightness varies smoothly across the four separate pixels, errors can and do occur when there are large differences between adjacent pixels. The mathematical process, known as 'de-mosaicing', then causes distortions known as 'edge artefacts'. Once data from different pixels have been mixed together, they cannot be separated again, if the colour is not wanted.



Thus, if the end use is to be a monochrome image, all this combining and mixing of information from four pixels can be eliminated. Removing the Beyer filter array yields a final image that accurately reproduces the full resolution of the sensor.


I illustrate the principles of using a Beyer array to create a colour image in this article on my website : http://home.btconnect.com/mike.flemming/usingraw.htm
__________________
Mike
visit my Natural History Photos website:
http://home.btconnect.com/mike.flemming/

Last edited by MikeOxon; 31st July 2018 at 06:46 PM. Reason: typos
Reply With Quote