From Charles Darwin's son Francis's Reminiscences about his father:
In all matters of art he was inclined to laugh at professed critics, and say that their opinions were formed by fashion. Thus in painting, he would say how in his day every one admired masters who are now neglected. His love of pictures as a young man is almost a proof that he must have had an appreciation of a portrait as a work of art, not as a likeness. Yet he often talked laughingly of the small worth of portraits, and said that a photograph was worth any number of pictures, as if he were blind to the artistic quality in a painted portrait. But this was generally said in his attempts to persuade us to give up the idea of having his portrait painted, an operation very irksome to him.
The keen photographer in me rejoices at my hero's preference for photographic portraits over more traditional daubs—even if it seems this was at least partly an excuse to avoid having his own portrait painted.
As with so many other things, I'm with Darwin on this one: there is something undeniably special about a photographic portrait that any number of paintings and drawings simply cannot capture. Echoing Darwin's sentiments, George Bernard Shaw reportedly said that he would exchange every painting of Christ for one snapshot. When you look at a photographic portrait, it feels as if you are looking at the real person; not some artist's impression of them. Photographs seem to give you the genuine article. The camera famously (but not always correctly) does not lie.
I have a hunch that one contributing factor to Darwin's phenomenal popularity as a scientist—apart from his being a total dude, who came up with one of the most important ideas in science—is the fact that the new-fangled photography started coming into its own at around the same time that Darwin returned home from his five-year voyage around the world aboard HMS Beagle.
The ‘birth’ of photography in 1839—just three years after the end of the Beagle voyage—came at just the right time for Darwin to be photographed in his scientific prime. The oldest photograph we have of him is an 1842 portrait with his son William. I would contend that one, albeit minor, reason why we find Darwin so interesting is that we know what he actually looked like:
As historians of science are forever reminding us (although nobody listens to those killjoys), we enter dangerous territory when we start to discuss the ‘first’ person to do X, the ‘lone genius’ who invented Y, or the ‘Father of’ Great Idea Z. The history of science, they insist on pointing out, is a history of collaboration—albeit sometimes highly rivalrous collaboration, in which jealous individuals failed to acknowledge their peers' and predecessors' work. Scientific advance is an iterative process, improving on what went before, sometimes steadily, sometimes in fits and starts. Very much like evolution, in fact.
The history of photography illustrates this point rather nicely, as the following two paragraphs lifted directly from the Wikipedia entry on the subject show:
The history of photography has roots in remote antiquity with the discovery of the principle of the camera obscura and the observation that some substances are visibly altered by exposure to light. As far as is known, nobody thought of bringing these two phenomena together to capture camera images in permanent form until around 1800, when Thomas Wedgwood made the first reliably documented although unsuccessful attempt. In the mid-1820s, Nicéphore Niépce succeeded, but several days of exposure in the camera were required and the earliest results were very crude. Niépce's associate Louis Daguerre went on to develop the daguerreotype process, the first publicly announced photographic process, which required only minutes of exposure in the camera and produced clear, finely detailed results. It was commercially introduced in 1839, a date generally accepted as the birth year of practical photography.
The metal-based daguerreotype process soon had some competition from the paper-based calotype negative and salt print processes invented by Henry Fox Talbot. Subsequent innovations reduced the required camera exposure time from minutes to seconds and eventually to a small fraction of a second; introduced new photographic media which were more economical, sensitive or convenient, including roll films for casual use by amateurs; and made it possible to take pictures in natural color as well as in black-and-white.
Frenchman Daguerre's stunningly beautiful, self-promotingly eponymous daguerreotypes proved to be something of a technological dead end. Amongst other drawbacks, they could not be reproduced. Which is why, if the historians of science will allow me, my totally unbiased vote goes to Englishman Fox Talbot, with his invention of the photographic negative, as the true Father of Photography.
As a sop to the historians, I should point out that Fox Talbot received more than a little help from the astronomer John Herschel, who had previously found that hyposulfite of soda dissolved silver salts. This discovery made it possible for Fox Talbot to ‘fix’ his exposed negatives, thereby preventing them from fading in daylight—an idea subsequently copied, without acknowledgement, by Daguerre. Kudos also goes to Herschel, incidentally, for inventing the word ‘photography’, and re-purposing the mathematical concept of a ‘negative’ into a photographic context.
Ah! But what about poor Thomas Wedgwood? The chap who, as far as we know, first had the frankly brilliant idea of trying to get a camera obscura to produce images automatically on materials coated in light-sensitive chemicals. He even succeeded, to a limited extent. Doesn't he deserve some credit? He might not have been the Father of Photography, but does he not at least deserve to be dubbed its Uncle?
He was also, entirely coincidentally, the uncle of none other than Charles Darwin.