Even though we ARE Nikon lovers,we are NOT affiliated with Nikon Corp. in any way.

English German French

Sign up Login
Home Forums Articles Galleries Recent Photos Contest Help Search News Workshops Shop Upgrade Membership Recommended
members
All members Wiki Contests Vouchers Apps Newsletter THE NIKONIAN™ Magazines Podcasts Fundraising

Moiré and False Color. A discussion amongst Nikonians.

DigitalDarrell

Knoxville, US
5988 posts

Click to send email to this author Click to send private message to this author
DigitalDarrell Team Member Founding Member of the Nikonians writer Guild. Author of most of the NikoniansPress books. Donor Ribbon awarded for his generous support to the Fundraising Campaign 2014 Donor Ribbon awarded for his very generous support to the Fundraising Campaign 2015 Charter Member
Mon 26-Mar-12 04:41 AM | edited Tue 27-Mar-12 09:55 PM by DigitalDarrell


As I write this new book, Mastering the Nikon D800, I have to be very careful to make sure I understand certain highly technical matters correctly. Otherwise, I might write something incorrectly. I am going to be writing about moiré and false color potential in the D800E and how to avoid it. Therefore, I wanted to discuss this issue with a few Nikonian color scientists. Here is my current understanding of the cause of false color and moiré interference patterns:

False Color Cause

From what I understand about the low-pass filter, all it does it slightly divert the light rays so that surrounding pixels share the color. That way, no one pixel can report a color inaccurately when the fineness of the subject's pattern closely matches the fineness of the sensor, a situation that does not allow normal color interpolation.

In other words, without the low-pass (AA) filter (e.g, D800E), a single pixel being hit by a pixel-sized white light source will report its own color, red, for instance, even though the light is white. That causes a red false color. The other pixels (green and blue) can do the same incorrect reporting when the source light has the same pinpoint fineness as the sensor's pixels. By blurring the light rays slightly, surrounding pixels in the RGB bayer pattern receive some of the same light and normalized color interpolation can then occur.

Moiré Patterns

Moiré interference patterns can also result when the fineness of the subject's pattern approaches the fineness of the sensors pixels (within 50%). The frequency of overlapping patterns can cause some interference patterns that are nearly impossible to remove once allowed into the image.

Solution

Subsequently, the Nikon D800 has a relatively weak low-pass (AA) filter——per my own direct observation of my D800's images——to solve both problems. Since this anti-aliasing action blurs the image, the camera must resharpen it.

Do you detect a flaw in my reasoning or understanding?

==============================================
Darrell Young (DigitalDarrell) www.pictureandpen.com
"Better too many words than not enough understanding."
==============================================

Subject
ID
Reply message RE: Moiré and False Color. A discussion amongst Nikoni...
1
Reply message RE: Moiré and False Color. A discussion amongst Nikoni...
2
     Reply message RE: Moiré and False Color. A discussion amongst Nikoni...
3
          Reply message RE: Moiré and False Color. A discussion amongst Nikoni...
4
Reply message RE: Moiré and False Color. A discussion amongst Nikoni...
5
Reply message RE: Moiré and False Color. A discussion amongst Nikoni...
6

G