In the Develop module:
- Open Masking. Click the Masking icon (the dotted circle just under the histogram), or press Shift+W.
- Create the mask. Click Create New Mask and choose Luminance Range. If the eyedropper becomes active, ignore it or press Esc; you’ll set the range by hand.
- Cover the whole image. In the mask’s options you’ll see a Range bar with handles. Drag the left outer handle to 0and the right outer handle to 100. Then drag the inner handles all the way out as well, so there’s no falloff and every tone is fully included.
- Check the coverage. Turn on Show Overlay. The overlay color should cover the entire image evenly, including the deepest shadows and brightest highlights. Turn it off again.
- Add the dim-room adjustment. In the mask’s adjustment sliders, lower Exposure and Contrast until the screen matches your print in evening light.
- Rename it. Double-click “Mask 1” and call it “Dim sim.”
Then save it as a preset with only Masking checked, as before. Because it selects by tone rather than position, it covers the whole frame regardless of crop or orientation.
Then apply preset to desired photo. Adjust until it looks good. Then hide that adjustment layer and hit print.
For my Dining Room that's an exposure adjustment of -0.57.
Oh, and I set my monitor for D50 for printing with nit value of 60.
