Leica Monochrom and Lightroom export problems

Question

I am using the latest version of LR on a 2011 Mac Book Pro. I am running into problems when I export Leica Monochrom DNG files that are shot AT AND ABOVE ISO 6400.  Lightroom is brightening the files on export a lot so that the final exported file does not look anything like what my edit looked like. This only happens with full resolution exports.  Other Leica MM users have experienced the same issue.  I have photos and screen shots to prove this.  What is the problem?

Answer 1

What I was hoping for was an original raw image with all the OP’s adjustments intact so I could demonstrate what was happening at various zoom levels and with different settings, but that seems overly difficult to come by so I’ll give my analysis of what is happening and what to do about it:
The brightening has to do with the micro-noise-grain that has been excessively sharpened making the image a mixture of mostly white and mostly black dots immediately adjacent to each other rather than continuous tone of a low-ISO image.  This is not an error with LR or with the camera, and will happen with any such image from any camera.  The “brightening” is merely the visibility of the white granules at 1:1 zoom.  When a zoom level less than 100% is used, LR or Windows Photo Viewer or Mac Preview must determine how to combine multiple pixels together to represent one output pixel in the reduced-sized image.   Different viewers use different methods to combine adjacent pixels into one.  Some use Average, some use Median, some use the value of a single pixel position to represent the entire reduced-size combination pixel—this is called nearest neighbor and is the fastest but least accurate.  LR is known to use a fast but inaccurate resampling algorithm which is why there is a warning on the Detail panel to use 1:1 zoom to judge sharpening and noise adjustments.
The problem here is that this lightening and darkening depending on zoom level is messing with toning adjustments, so how to tone and adjust such images, is to temporarily turn off Detail sharpening and turn up noise-reduction then adjust toning in Fit view.  Then zoom in to 1:1 and adjust the noise-reduction up or down to remove most of the obvious grain, and turn up sharpen masking so all you’re sharpening is edges.  Maybe even turn off the Detail slider (set to zero) to keep from enhancing micro-noise texture.
If you do want grain for artistic effect then do that after you’ve removed the ISO noise.   The difference with high-ISO noise and added noise-grain is the high-ISO noise is single-pixel in size and will not be resampled accurately while the noise-granules created by the Effects panel can be control both in size and intensity so as not to respond negatively to resampling nearly as much. 
If you are exporting images to nearly full resolution then dial back the export sharpening quite a bit.  If you are resizing quite a bit smaller than any micro texture will have been averaged out by the resizing and adding more sharpening during Export sharpening will help things look crisp, again.