One of my favorite songs by Dean Martin …
When the moon hits your eye
Like a big-a pizza pie
That's amore …
Wait … that’s not it … how about …
When the eel takes your eye
Like a big pizza pie
That’s a Moray …
Again … not where I was going. I digress …
Moiré is an interference pattern of false colors that is caused by patterns that interfere with the pattern and frequency on the Bayer sensor. In other words, when the two get too close together, you get interference patterns.
It makes sense, then, that moving closer or further from the subject will actually change the final result, eliminating the moiré at some point in either direction. Well, but a bit of a fluke, I got the absolute perfect examples of this during the shoot for my dynamic range tests. The D7000 has 16Mp on an APS-C sensor, and apparently does not have a strong anti-aliasing filter. I surmise this from the strength of the aliasing I got when shooting the chairs in my back yard. These have a plastic weave that is very regular and thus is the perfect candidate for creation of moiré.
My first shot was at 27mm EFL (effective focal length) and the second at 39mm EFL. The difference is startling …
As you can see … both chairs have a beat frequency that creates alternating bands of color that follows the contour of the chair. Very cool.
Now, zoom in just a bit and what happens …
The closer chair is now fine. But the one just a foot or two further away is still within moiré range.
That’s as clear an example of magnification versus interference that I could imagine.
