Noise in ACR

[Etienne Cassar]

Is anyone having the same issues like I am having.  The images in the preview window of ACR 4.5 are appearing quite noisy when viewed at any zoom level but 100%.  Same thing doesn't happen when the same image is opened up in Photoshop CS3.  So when I view an image at say50% zoom level in ACR it appears noisy, but then when the image is opened up in photoshop at 50% zoom level the noise is all gone.
Any idea of why this is happening?
Etienne Cassar

[madmanchan]

This is intentional. Noise reduction is only applied to images viewed at 100% or higher while inside the CR plug-in.

e.g., if you view at 25% or 50% then NR is not being applied. This is to help speed up preview rendering.

[Etienne Cassar]

Oh. Thanks for letting me know about that.  I am getting noise in the sky region of my pictures when I decrease the luminance of the blue channel.  I do this when increasing the saturation of the blue channel still doesn't give me the blue sky that I want.  So I reduce the luminance of the blue channel, and that is when the sky becomes really noisy.  The noise however disappears as soon as I go to 100% viewing or open the image in photoshop.