Nikon D4s: Bayer processing breakthru?

Started Jun 4, 2014 | Discussions thread
Scottelly Veteran Member • Posts: 9,962
Re: Thanks to all: Nikon D4s: Bayer processing breakthru?

Tom Schum wrote:

PrebenR wrote:

You can always blur your Foveon image to look like CFA. But don't expect a CFA sensor to invent data point it does not have.

I wonder if you can tell me how to use unsharp mask to selectively blur out detail finer than 0.4 pixel radius without touching any of the other detail in the image.

So far as I can tell, unsharp mask will sharpen to a radius but will not "unsharpen" to the same radius. To do that I would have to set the % slider to negative values and it doesn't go lower than zero. This might be entirely my own misconceptions about unsharp mask and they are getting in my way. I need some help here!


Try upscaling the image to 200% Tom. Then use a radius of 1. Otherwise try upscaling by 300% or 400% and use a radius of 1, 2 or 3. Experiment. That's how you learn. When all is said and done, you can downscale back to the original size or smaller, if you like . . . of course.

Here are two similar images. The first is one of the samples from the SD1 review here on DPreview, and the second is that same image upscaled by 300% and then blurred in GIMP 2.8, using the Gaussian Blur filter, with a value of 4 for x and 4 for y. Then I downsized it to 4704 wide, which returned it to its original size.

Original test image from SD1 Merrill review samples here at DPreview

Test image edited by upsizing 300%, blurring 4x and 4y, and then scaling the image back down to 4704x3136

If you open these two images in new tabs and flip back and forth between them (after resetting your browser zoom) you will see the difference a little gaussian blur can make. It's not a lot, but can be less or more, depending on the values you set. Do you like the second image better than the first? If so, then I suggest you stick with CFA sensors . . . with AA filters. The D610 should do just fine.

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