"Moiré with Capture NX2" Sun 25-Aug-13 04:10 PM by William Rounds
Below are two photographs of zebra I took in Nairobi National Park a couple of years ago (with a D60). As you can see, the area between the eyes and the muzzle seems to be fuzzy compared to the rest of the image. Is this a moiré problem? Is it possible to select the area and somehow clean it up?
#1. "RE: Moiré with Capture NX2" In response to Reply # 0 Sun 25-Aug-13 11:59 PM by jrp
San Pedro Garza García, MX
WOW! What a trip that must have been. I don't see moire; what I see is a probable insufficient shutter speed (more noticeable in the tails and hair) and/or too narrow depth of field. No way to tell as the images have been stripped of EXIF data.
#3. "RE: Moiré with Capture NX2" In response to Reply # 0
I don't see moire in the posted images. If you want to share something that detailed, you might want to capture a screenshot of whatever you are using to see moire. Then save the screenshot as a JPEG and size it for posting here.
The key to moire in an image is that it gets more pronounced and visible as you zoom in closer. Moire in an image is always there.
The resolution of the D800 causes moire to be seen (in a sense "created") in images without moire due to resizing and interpolation. Converting an image to a smaller size is a common example, but you might see it in printing or viewing at normal or zoomed levels. If you just see moire on the screen, it won't necessarily show up in a print. Seeing a full image on your computer means resizing a native image from full size to approximately 900-1000 pixels in width (automatically done by your computer). Printing works in a similar manner - it often involves resizing. Many of these resizing algorithms involve automatic sharpening - particularly when you are viewing or printing at smaller than the full file size. That sharpening can cause moire.
The solutions are to: 1) ignore the moire if it does not matter for your final output. This usually works.
2) If it is visible in a print, try a different resizing algorithim. Photoshop and Lightroom offer a number of choices and you can experiment to see which one works best. The default for downsizing is typically Bicubic Sharpener.
Your printer has a desired output size to align ppi of your image with dpi of your printer. For Epson Professional printers - 4900 and up - you would use 360 ppi to match the printer and avoid the need for printer interpolation. Canon and HP, as well as lower level Epson printers have lower dpi and optimal ppi. (this comes from Jeff Schewe's new book).
For a print, you can resize in more than one step to cause the interpolation to work differently. Using two steps to downsize might eliminate moire.
If your final output is a small JPEG for viewing, you can also vary the resizing algorithm or resize in two steps. You might even just resize to a smaller or larger size.
Some resizing for JPEG's includes sharpening by default. Photo Mechanic makes that an option. Try turning it off.
Any problem involving moire caused by sharpening can be reduced by applying less sharpening - or noise reduction. You can selectively apply a little noise reduction or gaussian blur to reduce or remove moire. I would apply these techniques selectively.
If the moire is in the image, and is visible to a greater extent by zooming, you need to worry about it a bit more. Most software programs offer some moire reduction or removal tools. Capture NX2 offers such a tool - and so do Lightroom and PS. They work well at low levels, but they normally work by globally softening the image so you may need more sharpening.
Start by removing any capture sharpening or sharpening applied early in your workflow. You might still find there is no moire in the image and your capture sharpening created moire. The techniques for applying noise reduction and gaussian blur may also help eliminate moire.
Keep in mind noise reduction and gaussian blur can be applied to just luminance or the color channels. You might experiment with applying these tools just to color or just to luminance. You can also reduce saturation selectively and some moire is not visible. And all these tools can be applied to varying opacity levels, so you can apply a stronger edit with lower opacity or vice versa.
#4. "RE: Moiré with Capture NX2" In response to Reply # 3 Mon 26-Aug-13 10:39 PM by William Rounds
I took the slider on the TIFF file to 155%, cropped the face and then saved it as a JPEG with no other processing.
There seems to be less moiré or fuzziness to me, except when I downsize the file for web posting. The camera is a D60. The lens is a Nikkor 18-200mm at 200mm, f/5.6 and 1/1000th of a second, ISO 100. And for a 155% view, with no sharpening, it doesn't seem that there is either excessive movement nor is it particularly out of focus.