I wonder if any one else has the problem shown in the screen shots. The one timed at 17:24:39 is taken directly from DXO PL4 and shows a number of white pixels in the shadow area under a rock. The other screen shot is taken from a JPEG exported from DxO PL4. In this second image the white dots of the first have been removed but others appear. Other applications do not have any issues with these white pixels.
I am unable to post the raw file but should anyone want to have a look I have placed the raw and dop file on my drop box.
The white dots are hot pixels, which are to be expected (especially in such a dark region of your photo) when such a long exposure (13 seconds) is used. PhotoLab’s noise reduction does handle them properly:
A. If you zoom in 75% or greater in PhotoLab, most of the dots disappear.
B. I see you are using HQ noise reduction. Using one of the PRIME noise reduction modes will improve your exported images further. (You won’t see the improvements in the PhotoLab image viewer - just in the noise reduction palette loupe and in the exported image file.)
C. If you can’t use PRIME, then raise the “Dead pixels” correction slider more. (You have it set at 62.) Use the repair tool with a small brush size to remove any that Noise Reduction can’t take care of.
D. Turning on Moire removal can also reduce hot pixels further.
Thanks Greg for your very helpful and detailed reply.