Originally Posted by Kilgore
No matter where you set the Brightness you will never see luma 16 or below. So you set the Brightness so you see 17 flashing and then lower it until it just disappears and all is good.
Again, if you can see the gray luma bar marked 17 flash that means that luma 16 is also displaying. Your comment suggests that gray luma values 1-16 are displaying the same as 16.
If (as would be normally expected) Expanded on an Epson meant it was expecting PC levels, and you fed it a Video Levels based signal, you would never EVER see BTB or WTW material.
Feed a video range signal into a display set for computer levels and the display will tend to show what you label BTB (1-15) and WTW (236-254). Computer levels suggest that you want to display levels 0-255, where 0 is expected to represent black and 255 is expected to represent white. Feeding video levels into the computer range scenario means 16 (video black) is simply elevated to 6% of the expected range and 235 (video white) would fall around 92% of the expected range, and the entire 1-254 video range would be expected to show up on a display set to differentiate 0-255.
On the other hand feeding a computer signal (0-255) into a display set to expect a video level signal is generally more likely to cause easy to spot issues, since the video range only really expects to display 16-235. The real video range is actually 1-254, but 16 is expected to represent black and 235 is expected to represent white. If you feed a computer signal into a display that clips information below 16 and above 235 then you will lose dark gray and near white information from the computer signal, since 0-15 and 236-255 would not be expected to display in such a scenario.
BTW, if I calibrate using Normal, my approximate settings are Contrast = 0, Brightness = -7. Set it to Expanded, and my approximate setting are Contrast +10, Brightness =-10. In either case, I would be seeing luma 17-234.
I'm not going to go look up what the default settings are, and I have no idea how either the default or modified settings relate to luminance levels, so the settings really don't have much context to me. On that note I'm going to drop out of the Epson-specific discussion. Unless metalguy has a question in relation to observed display performance, it seems somewhat pointless here.