> dwb I think you may need to carry out monitor recalibration
I have ckecked the settings. The brightness was wound right up, so I set it to the central position and then went to the site that Peter referenced in his first post. With the central brightness setting, I couldn't see any difference in the first three black squares at all. I read the article looking for enlightenment on what to do, but apart from checking the white point temperature - my monitor was set to 9500K rather than the 6500K of sRGB - there wasn't much help there, so I wound the brightness back up to the point where the 4 black squares showed some difference. The setting was back where it started.
As for the gamma test, I don't think my eye sight is up to seeing the patch with any sort of clarity from 10 feet away
So I have made a change. My monitor temperature is now 6500K which is correct for the Windows (and Internet) sRGB colour space.
I have reexamined the images and still place #4 first.
I would still prefer #2 to #1 and #3 as it shows more detail, but this preference is based on information content not on aesthetics. ie I would choose 2 to illustrate a "how to" article but 1 or 3 to present an overall impression. This is in the absence of #4 being available. It would appear that this choice is a personal quirk of mine compared to the rest of the posters, but hey, variety is the spice of life.
My lighting conditions are still less than ideal, it's another bright sunny day. My monitor is not in its first flush of youth either, so that may also be a factor; it will be 8 years old this summer.
David