armis wrote in post #14820429
Constrast seems way higher in the LR screenshot, so you're not really comparing the outputs. Any NR in Aperture? Occasionally ACR (6.something for me) shows some noise in the preview screen, but when I open it in CS5 it disappears; I'm not sure why, but try exporting the LR pic to jpg and see if it's all somehow magically fixed?
Same in both LR4 and CS5 and 6 on different machines. Contrast is higher in LR, but even with the contrast dialled back severely it still has the red blotches.
kirkt wrote in post #14820839
Are we looking at the default processing options for LR? You will need to adjust the image to get the look you want - this will include adding some noise reduction (in this case chroma NR) to suppress the color noise in your image.
Also - the exposure info on the LR screen shot says that the shutter speed (exposure time) was 66 seconds. Is this correct?! No wonder you have noise. What are Aperture's default NR settings versus LR? Can you provide the same screenshot from LR with some NR applied? My hunch is, that if you turn NR off in both applications and then make some basic tonal adjustments so that the WB, exposure and contrast are similar, you will probably see similar noise artifacts in both previews.
Even cranking the chroma reduction to 100 doesn't remove these spots, they are still there in the LR renders.
In comparison the default settings with no NR in Aperture doesn't have them at all.
Yes its a 66 second shot, it is likely to have some noise, but of the other long exposure shots I've taken over the last few months none have had these red blotches.
stsva wrote in post #14822124
Good thoughts from kirkt. It looks like you might even have one or two "hot" pixels in the LR image because of the long exposure. Check your chroma/color NR settings for sure, and proceed from there.
Its not hot pixels, the red blotchy spots are clusters of 10-20 pixels together.
imjason wrote in post #14822476
i dunno if this is the case still for LR4 (ihavnt upgraded yet), but for a more accurate representation of noise reduction, you need to view the photo in "library" module. in the "develop" module, some times the noise reduction is not apparent until you zoom in. its a rendering compromise that Adobe made to speed up editing by not fully rendering all the adjustments when youre zoomed out.
That is zoomed in, both at 100%.
Have resized the original image, but you lose the ability to see the blotches clearly.