Hello,
I did some testing on Gamma correction and on tone mapping with Poser.

My test scene was a unit square with a pattern of RGB colors (full and half intensity), plus some greyscale squares. The only light in the scene one sun, shining vertically onto the square. 
I did renders with 50% light intensity, 75% and 100%.

The camera pointed directly to the square.

This is what I got:

Poser 7 or Poser Pro without gamma correction.
 No surprise: The resulting image at 100% light intensity was almost identical to the texture (exactly concerning the color values, differences only due to unprecise camera positioning).

With 50% light or 75% light, the RGB values were just multiplied by this.

Poser Pro with gamma correction (using 2.0 as gamma for simplicity): As expected, the color values were exactly what you would expect when squaring them. Also every color channel treated separately / independently.

 Interesting was, that the maximum color value the rendered image had, was much less:

161 for 50% light

198 for 75% light

221 for 100% light

The color values for a darker color (RGB values 128 out of 255) were:

100 for 50% light

135 for 75% light

161 for 100% light

So my conclusion is that the main purpose of tone mapping is to have some stretch for
overly lit images, and therefore it is very different to PoserPro's gamma correction.

Best regards,
  Michael

P.S.: Please find here the results for the wider color ramp (RGB values 16, 32, 64,128,255 in the texture):

50% light: 15,29,56,100,161
75% light: 22,42,80,135,198
100% light: 30,55,101,161,221
 

What can be observed very nicely is, that the values for 50% light and 100% light correspond to each other, i.e. identical values of the product of RGB texture amount and light intensity are still mapped to the same render image color.

This might seem trivial, but i currently have trouble to get even roughly related results with Carrara, no matter if with or without gamma correction.

P.P.S.: Here are the Carrara result (C7.2) without gamma (no ambient, no skylight, one sun, same setup)

50% light: 12,25,54,108,219
75% light: 15,30,63,126,254
100% light: 15,30,63,126,254 (did I mix the files?  It's not THAT late. Maybe light intensity is capped)

Best regards,
  Michael

www.renderosity.com/mod/forumpro/showthread.php

ooooh, thanks!  I will bookmark that one!

Just as a last P.S. my final C7 results:  I tried 25%light in C7 without gamma:  3,6,15,30,62

And C7 with gamma:

25% light: 7,14,31,62,126

50% light: 10,20,44,88,179

75% light: 12,25,54,108,219

100% light: 15,30,63,126,254  (surprise! Matches Poser  WITHOUT gamma correction)

So Carrara does gamma correction very different compared to Poser. It seems that in C7, the light value is gamma corrected, but the texture RGB values not.

Hi,
very last post on this: The C7 results match the Poser results, if in Poser the (inverse) texture gamma correction is enabled.

Best regards,
   Michael