[got2bNC]

Hey all,

In the last batch of photos I uploaded from my camera was a picture of my mailbox. I shoot in raw (DNG) and use Lightroom 3 to edit and manage my photos. The mailbox picture looked fine as shot in Lightroom 3, so I exported a JPEG. But when I opened the JPEG copy, I noticed significant moire on the mailbox. The picture uploaded in Lightroom, however, shows no moire whatsoever. I then exported a DNG version of the image, opened it in PS Elements 6 and the moire does not appear.

What is it about exporting a JPEG that makes the moire appear? Is there a way I can tell when there is going to be a moire issue before exporting the JPEG?

Thanks for any advice!

[MadMathMind]

Moire occurs when an object has a pattern that is finer than the resolution (not necessarily pixel count) of the image or display. If you look at an image on the camera's viewscreen, for instance, you may see moire, but when you open the file on your computer, it's gone. Moire can be an artifact of the display just as much as the image itself.

In this case, you are losing resolution when you compress to JPEG. High-frequency information is discarded or reduced in compression, which means the fine details are lost. That's where your moire is probably coming from. Save it at max quality and you may not see it.

[DSims]

And try saving at Max (original) resolution, if you're not already.

[got2bNC]

Thanks for the advice, guys!

It appears you're right, MadMathMind, that this is a display issue. I went back and realized that I wasn't the viewing the image at full/actual size. I then selected to view at "actual size" and POOF, the moire disappeared.

I'm glad this turned out to be a non-issue