16 Replies Latest reply on Oct 23, 2007 4:49 AM by Ramón G Castañeda

    Strange artifact in some NEF and .dng files

    Neil_Keller Level 1
      Using a Nikon D80 with 4 GB Sandisk Extreme SDHC card; shooting full resolution NEF; Mac G5, Mac OS X 10.4.10, images are run through Adobe DNG Converter 4.1. Image is opened in Camera Raw 4.1 (and now 4.2) window within Photoshop CS3 Extended.

      In some photos with dark areas, there is a single, tiny, transient on-screen artifact in form of a red dot, either two or three pixels square, which always appears in the same location against, say, a dark sky or trees. It can persist or literally disappear on its own after about two seconds. If the file is reopened in the same session, the red dot may not be there at all. If the loupe tool is used, it always disappears within the loupe after about two seconds, even though it may persist in the unmagnified screen. The good news is that opening the image as a .psd in Photoshop shows no sign of this anomaly, no matter how greatly magnified.

      Note: It can also appear if I drag the NEF or .dng file over to Preview. But in this case, it does not disappear.

      Does anyone have a clue what may be causing this?

      A screen shot comparison from Camera Raw 4.1 is attached below. The left image shows the dot in place in the section of the photo and with the loupe.The right image shows the dot gone, but persistent in the unmagnified image.

      Neil