On 2015 Oct 05, Lydia Maniatis commented:

It's been a month since I posted my comments on this article and on the original Blakeslee and McCourt article. A sharp increase in visits to the target articles post-comment seems to indicate that the comments are being read, but no author or reader has put in their two cents, either here or on PubPeer. I think that my argument against the "brightness-is-perceived-luminance" idea is sound and straightforward. Am I wrong?

On 2015 Sep 06, Lydia Maniatis commented:

I fully agree with the latter part of this commentary but disagree with the author's concession that, in lightness experiments, "when illumination appeared homogeneous, lightness and brightness judgments were identical. There is nothing new here. It is well known."

Brightness is currently being described, including by Gilchrist, as the perceptual correlate of luminance. But there is no perceptual correlate of luminance, even under (apparently) homogeneous illumination, and this can be proved as follows:

We ask an observer to report on the lightness of a set of surfaces which don't produce the impression of shadows or transparency. Then, in a second session, we present the same set of surfaces under a different level of illumination. The lightness reports for the surfaces will stay essentially the same, even though their luminances may have changed substantially. So to say that people are making "brightness" judgments in either the first or the second or in any case doesn't seem reasonable.

On 2015 Sep 06, Lydia Maniatis commented:

I fully agree with the latter part of this commentary but disagree with the author's concession that, in lightness experiments, "when illumination appeared homogeneous, lightness and brightness judgments were identical. There is nothing new here. It is well known."

Brightness is currently being described, including by Gilchrist, as the perceptual correlate of luminance. But there is no perceptual correlate of luminance, even under (apparently) homogeneous illumination, and this can be proved as follows:

We ask an observer to report on the lightness of a set of surfaces which don't produce the impression of shadows or transparency. Then, in a second session, we present the same set of surfaces under a different level of illumination. The lightness reports for the surfaces will stay essentially the same, even though their luminances may have changed substantially. So to say that people are making "brightness" judgments in either the first or the second or in any case doesn't seem reasonable.

On 2015 Oct 05, Lydia Maniatis commented:

It's been a month since I posted my comments on this article and on the original Blakeslee and McCourt article. A sharp increase in visits to the target articles post-comment seems to indicate that the comments are being read, but no author or reader has put in their two cents, either here or on PubPeer. I think that my argument against the "brightness-is-perceived-luminance" idea is sound and straightforward. Am I wrong?