As I’ve begun to take more and more portraits this year with my Lumix GH5, I’ve started to wonder why I’m getting rainbow patterns on some of them — specifically when people wear sports coats or other detailed clothing.
But why would changing a camera increase these patterns? The answer surrounds the removal of anti-aliasing filters in today’s modern, high-resolution cameras.
I reached out to photographer friend Michael Muraz about this, and luckily, there’s an easy way to get rid of it in Lightroom.
What is Moiré?
Moiré develops in your photographs when the clothing that a person is wearing has some repetitive patterns, like lines or dots. These actually go above and beyond what your camera sensor can recognize, and thus the camera produces the rainbow-colored lines.
It typically occurs in fabric-type material, like sports coats.
So, why would camera companies get rid of anti-aliasing filters? The benefits to doing so are substantial. You’ll see sharper images and more detailed patterns in your photographs. For older cameras with the filters still included, you’ll rarely see moiré in your images, however, the details in your photographs won’t be as sharp.
Get Rid of It Fast!
I usually do all of my other edits first, as I’ve noticed that, there’s a possibility the moiré might increase or decrease depending on how I alter my image. When the rest of the edits are completed, I pull out my local adjustment brush in Lightroom.
From there, I bump up the moiré slider. There’s no need to bump it up all the way. In my tests, between 40 and 80 seemed to work best, depending on the harshness of the effect.
Then I simply just brush over the moiré, and it disappears.
Can I Avoid Moiré?
Depending on the situation, you can work with certain techniques to lessen the effects of the moiré.
First, you can close your aperture. Going from f/4 to f/8 might reduce the moiré significantly. Secondly, you can also zoom in on your subject. This makes the detail in the problem area larger, lessening the moiré present.
And while you can certainly avoid moiré through these means, they could introduce other problems. Closing your aperture, for instance, will make the background sharper. Likewise, zooming in might not allow you to capture the composition you desire.
Moiré isn’t what we want to see, but it’s a side-effect of not having a low-pass filter on your camera. Luckily, with tools like Lightroom, it’s easy to get rid of.