NavList:

Personally (that is, me, myself), I'm not too worried about what might be right or wrong with the painting. It's a work of art, and that requires no further justification. That said, yes, I, too, started looking at the positions of the shades and such... But then I stopped myself... Have to stay focused on the main point: 
I am concerned about the Wikipedia article about the painting, and I brought it up for discussion so that we could air out what those flaws might be. 

The section that has issues currently (pre-edits, which will follow, no doubt) reads:

Most other sights are made at dawn or twilight. [...] Homer has taken some artistic license, showing the figure at left using an octant to take a reading of the sun, the other apparently reading the altitude of a completed sight on his octant. In reality, both observers would have had their octants to their eyes, rocking them back and forth to determine the highest elevation reached by the sun, thereby establishing local apparent noon.

As Doug has already noted, this is wrong or at least misleading. First, the idea that "most" sights are taken during twilight suggests the bias of a person who knows only traditional late-20th century celestial methodology. In the 19th century, when the painting was created, twilight sights were relatively rare. It is simply wrong to say that "most other sights" were twilight sights (the confusing wording "dawn or twilight" is presumably just Wikipedia entropy). Also the complaint that both observers should still be continuously observing the sun "in reality" is erroneous. The focus on "rocking" the sextant is un-necessary. There is no evidence of "artistic license" in this painting, at least not in the celestial navigation details. The article is wrong on technical matters and misleading in its subjective analysis.

So why should we care? It's only Wikipedia. The problem is that Wikipedia articles are widely copied, and the usual warnings about not trusting Wikipedia evaporate. For example, at winslowhomer.org, which might be taken as an authoritative source on Homer's work by an innocent reader, we find this page, http://www.winslowhomer.org/eight-bells.jsp, which includes this text:

Most other sights are made at dawn or twilight. [...] Homer has taken some artistic license, showing the figure at left using a sextant to take a reading of the sun, the other apparently reading the altitude of a completed sight on his sextant. In reality, both observers would have had their sextants to their eyes, rocking them back and forth to determine the highest elevation reached by the sun, thereby establishing local apparent noon.

Notice that "sextant" in the version copied at winslowhomer.org has been replaced by "octant" in the current Wikipedia page, but otherwise the text is identical. This is a major problem with Wikipedia -- copying over to other resources.

Bill, when I posted about this on Facebook, you mentioned that the article used the word "sextant" (I think that was you). Were you looking at a different edition of Wikipedia? It appears that the references to "sextant" were replaced by "octant" in April, 2015. This is not an important distinction since it's fair in modern usage to refer to any double-reflecting instrument as a sextant.

Bill suggested:

Its no good just complaining - if Wikipedia has a mistake and you know about the subject you edit it... its just what you pay for the privilege of using it!

Actually, there's plenty of "good" in complaining. We hash out what's genuinely problematic and what's merely minor or perhaps a matter of opinion. If we treat Wikipedia as a work of literature in its own right, then it deserves to be objectively (and subjectively) reviewed once in a while, doesn't it? We don't always have to see it sitting under a sign that say "Under Construction: Road Legally Closed". Saying it's no good complaining sounds a bit like saying that no one should review movies. They should just make their own movies if they know so much about movies!

But yes, of course, if you have the time and inclination, you should edit when you find a problem on a Wikipedia page. It's easy. Or at least it should be. In the past decade I used to edit very regularly (I have done thousands of edits on pages with diverse topics) until about a year ago when it became nearly impossible to do anonymous edits from mobile phone IP addresses. Normally I would have brought up these issues on the "Talk" page behind the article directly on Wikipedia, but as I say, that has become nearly impossible. Besides, a Wikipedia page like this one has very low traffic and little interest from active editors, so it's quite unlikely that the proper "Talk" page would have generated any discussion.

Your claim here, Bill, that editing is the price you pay for the privilege of using Wikipedia is unfortunately unsourced and will be removed on the next edit. Ha ha (that's the sort of comment this would have generated on a Wikipedia page). But seriously, who says that that is the price you pay? That's not claimed in any official documentation for Wikipedia as far as I know. 

Finally, I wanted to add that the problems on this Wikipedia page about Winslow Homer's painting were pointed out to me this past weekend by a participant in my workshop "Celestial Navigation in the Age of Sail" at Mystic Seaport. This person may join NavList, and when he does, I hope he will say that he was the one who noticed the problems with the article. I'm sure he would be a valuable contributor to NavList. He has been collecting sextants for many years and has great knowledge of the instrument makers and their history, but he had not, until this past weekend, actually learned how to take and work celestial navigation sights.

Frank Reed
Clockwork Mapping / ReedNavigation.com
Conanicut Island USA