Exported Jpg a lot more grainy than edited photo in lighroom

[Danagordon]

My images have a lot more grains only AFTER it's exported.
I adjusted my settings in the develop module, including noise reduction. But the images that come out as jpg are noticeably grainier, especially the ones that already have a lot of noise and requires noise reduction.
I am comparing with jpg viewed 100% (zoomed out and opened to full screen) and full screen view of edited image inside LR.
My export setting is 100% quality, no output sharpening, at 300 dpi.

Same problem if I edit a copy (with LR adjustments) in photoshop. It seems like the grain-reduction is not working very well once the image is opened elsewhere, or exported.

comparison attached: Left side is the image opened on top of the lightroom view (right side). This is a screen shot so it doesn't look as bad, but still noticeable. It's worse when the jpg is opened full screen.

The noise is so bad that when I noticed it in jpgs, and thought I forgot to de-grain it.

Please help... I have to deliver these photos....

Thanks

 

[Conrad Chavez]

When you export from Lightroom, in the Export dialog box what is the setting for Output Sharpening?

The reason I ask is that if the Output Sharpening is set too high, it can re-emphasize grain and noise. If you find that Output Sharpening is on, try the next setting down (for example, if Standard sharpens the noise too much, Low is often OK), or try turning off Output Sharpening entirely. Whichever makes the image look the way you want.

 

[Danagordon]

No output sharpening at all....