Thanks Mr. Gil-
I wanted to do a bit of reading before replying to you.
First, I didn't know about being able to set the command line option.
I had been able to specify black point there.
I recalled writing this >>>" which if my memory serves, according to what I have read here is about 50:1."<<<
so I decided I needed to check out how well my memory was serving. Turns out not all that great!
After reading some search results here last night, it seems the 50:1 would be one extreme, the other between 250/300:1.
I do my editing in a cave pretty much so I have always had my white at 120, black point 0.15. I have been specifying 0.15 because that's what I had always thought that was desirable to have it set as low as possible and still be able to see a difference between RGB 0-0-0 and 1-1-1 as per the old Bruce Fraser test, which I have always been able to do.
So I have been specifying a 800:1 ratio without realizing what I was doing.
Further reading made me realize that the 120 white point may be too low, that is is below the native backlight limit something's being fudged.
FWIW, during the calibrating stage my display settings are gain:R 98, G97, B 94; Brightness 25%, Contrast 75%.
I am going to recalibrate/profile and try white at 140 and black at .5 which should be 280:1 if my math is right.
So thank you and Andrew both for helping me think this thing through!
PS-This also got me to thinking about just what the maximum contrast ration would be for a contone rgb print from a pro lab be?
If I print a test image that ranges from rgb 255-255-255 to rgb 1-1-1, is that a 255:1 contrast ratio ratio?