Image grainier after downsizing

[Rawfa]

Guys,

I was doing some tests with the D750 at iso 12800 and I've noticed that while I was treating the files they looked very clean on my screen but when I downsized them to 2000 x 1335 before saving them to jpeg they became much grainier, sharper and a tiny bit brighter. When I view the D750 raw files on Photoshop I view them at 23% and then after downsizing to 2000 x 1335 I view them at 65%...since 2000 x 1335 is larger than my screen resolution I would assume I shouldn't see the image grainier, sharper or brighter. To downsize I go to "image" and then "image size". Should I do something different?

 

[erudolph]

In Image Size check the interpolation method. There is a pull down menu near the bottom of the window and if I remember right it defaults to Auto. I think this causes the image to be sharpened when you down-res it. Try setting that to Bicucbic Smoother when you downsize it and see if that helps.

 

[foveon]

and dont watch at 23 or 65%, you just see display interpolation, view at 12.5, 25 or 50 or 100%