Get Leica M Monochrom Typ 246 at B&H Photo.
I’ll be publishing my examples and impressions as part of my review of the Leica M Monochrom Typ 246, including the use of red and deep red and other filters, focusing, metering and so on.
The beauty of Live View in the Leica M Monochrom Typ 246 is that no matter the filter, focus can be exact (red in particular focuses substantially more rearward vs other colors of light). See the focus shift behaviors (especially deep red) documented with the (original) Leica M Monchrom. The lack of Live View on the original MM was/is a fatal flaw for using yellow/orange/red filters because as much as f/8 was needed to mitigate the focus shift with a deep red filter (vs what the rangefinder indicated, it being calibrated for “white light”).
With the MM246, the focus shift can be seen easily: focus without the filter, then hold a red filter over the lens and watch it go blurry (use maximum aperture to make it obvious).
Shown below is the upper basin of one of my favorite places, the Hoover Wilderness Area.
Here, a B+W 091 filter (deep red) was used along with a polarizer. This combo works very nicely under these conditions, though the polarizer had minimal effect due to the clouds.