Beginner Colour Banding.........

[st599]

Now whether you (st599), David or anyone else disagrees with me or not, when this 'banding' occurs the fact is I can see it on the raw file when viewed on this laptop, fact! The mystery here seems to be why I see the 'banding' in the raw file.

No mystery whatsoever. You're not viewing the RAW file. The RAW file is literally the output of the sensor's analogue to digital converter. You can't view it.

To view a representation of it your PC is:
1) De-bayering the sensor output to an image.
2) Applying a colourspace based on ideal primaries
3) Applying a transfer function to match a generic screen
4) Scaling it to a suitable size for display
5) Converting it to a signal to go to the screen (probably 10 bits)

Then your screen is doing some internal processing to go from the ideal primaries and transfer function in the signal to the actual physical primaries it has in its hardware. This processing will be done in the screen at 6, 8 or 10 bits.

The banding is caused by either the processing or the screen. I've looked at the JPEG image on a PRM-4220, under reference conditions there's no banding. In a blacked out room with the peak white stretched to 6 times what it should be there is a tiny bit of banding in an area of blacks your screen won't be able to display. Therefore, it's happening in your display.

I'm definitely thinking that Michael @michael23 was correct with his theory of underexposure, the 'banding' always appears in the darker areas, longer exposures or exposures with a higher ISO its not there. Again, thanks for all the input, but I think its just down to user error.

As explained above - the banding visibility is proportional to brightness level not faults in exposure.

 

[Phil-D]

No mystery whatsoever. You're not viewing the RAW file. The RAW file is literally the output of the sensor's analogue to digital converter. You can't view it.

To view a representation of it your PC is:
1) De-bayering the sensor output to an image.
2) Applying a colourspace based on ideal primaries
3) Applying a transfer function to match a generic screen
4) Scaling it to a suitable size for display
5) Converting it to a signal to go to the screen (probably 10 bits)

Then your screen is doing some internal processing to go from the ideal primaries and transfer function in the signal to the actual physical primaries it has in its hardware. This processing will be done in the screen at 6, 8 or 10 bits.

The banding is caused by either the processing or the screen. I've looked at the JPEG image on a PRM-4220, under reference conditions there's no banding. In a blacked out room with the peak white stretched to 6 times what it should be there is a tiny bit of banding in an area of blacks your screen won't be able to display. Therefore, it's happening in your display.



As explained above - the banding visibility is proportional to brightness level not faults in exposure.

Ok, thanks