Noise added when viewing photos

[Capitol Reef Corals]

I am using a Nikon D3300 with a 40mm Macro Lens to take some photos and videos of my reef. I am pretty much a beginner when it comes to photography and cameras. I shoot in RAW and get .NEF files. When I first view the photo on my PC using the Photos app, the pictures are a lot more clear, then a second later, they get grainy almost like the app is trying to do some noise reduction.

Is that the case? Does anyone know what's going on and how to turn it off or fix it?

Here is a quick video that hopefully shows what I am seeing.

Thanks,
Stephen

 

[jent]

Your app appears to be adjusting the white balance and the exposure a little. The noise is already in the image, it just seems more apparent after the auto adjustment it's doing.

I don't know your software, but you may be able to disable any auto adjustments it is doing.