1916: The Tingewick Dog
In 1916, retired Scotland Yard Inspector Arthur Springer took this picture in Tingewick, Buckingham, England. At the moment he captured the photograph, there was reportedly no dog in the frame at all... and that sums up about all that is generally known about the photo.
A ghostly dog? (Fortean Picture Library - used with permission) [Larger version here]
Skeptics have argued the picture could be a double-exposure, so a purposeful fake. Others have noted that the people in the picture are not centered in the shot; therefore, the photographer had intended to include the dog... but it kept moving its head and tail, resulting in these not being clearly depicted.
Are these arguments correct? Without a traceable history it's hard to argue, especially given what modern photo editing software can accomplish in the hands of an expert trickster... so everything depends on the actual history of the photo, which could speak for or against the theories given.
Ask a Friendly Fortean
As far as I can tell, the image of the Tingewick dog has only been displayed on the internet since around April 2008. A great number of altered photos with fake phenomena appeared on the internet for the first time in the range of 2008~2010, so this is initially a bad sign. The Tingewick image, however, appeared in a November 2008 issue of Paranormal magazine, and it seems likely this is where it's internet career began. In this same online article the picture was credited to the Fortean Picture Library... which was a stroke of luck to find.
The Fortean Picture Library is an astounding collection of pictures and illustrations related to paranormal and unusual phenomena that was established around 1980 by Janet and Colin Bord, both well-known authors on anomalous topics [Link Here]. A quick email to the library confirmed that not only did they have the picture in their collection, but they could also trace the photo's history back to Springer's family and the tea party in 1916... so the image is definitely not a modern fake produced by software.
According to Janet Bord, the photo was one of many taken at the tea party that day in 1916. Through a family connection (of an extended nature), Janet and her husband Colin were able to obtain prints of all the tea party photos by Arthur Springer off of the original glass plates in 1976, including the single image that shows the anomalous dog. The earliest publication of the dog photo they know of after this was in their own 1980 book, Alien Animals.
Springer had taken several shots of the tea party that day, most from a little farther away than the shot with the dog (one shot even has Arthur Springer himself in it!), but all with the table and people centered in the shots. The original photo with the dog in it also has the table and people centered in it, with equal wall-space to either side of the table. It was only in the 1980 publication of the photo that it was first cropped to feature the anomalous dog, and it's this cropped version that has been reproduced ever since. This means that the claim that Springer meant to include the dog in the picture in incorrect, because the original does not actually focus special attention on the animal.
The dog in the picture was only discovered by Springer and his family after the tea party pictures were developed; none of participants had seen a dog present at the time, nor does the dog appear in any of the other photos from the same event. The Springers asked about town (which was not very large), but could find no one who owned a similar dog... so, as far as they could see, the dog should simply have not been in the picture.
The two most often proposed causes for the anomalous dog in the photo -- a possible double exposure, or a long exposure with an animal walking in and out of frame -- each rely on the same property of chemical photographs.
Previous to digital cameras, photographic media consisted of a surface coated with light sensitive chemicals that would react when exposed to light; after exposure, these then needed a further chemical treatment to stop the light sensitivity and fix the picture in place. Until the surface of such a media -- be it a tintype photo, a glass plate, or just plastic film -- was chemically fixed, any exposure to light resulted in further reactions on the surface; and if fully exposed to light, the photographic surface would simply turn blank, effectively erasing any picture recorded on it.
In the early days of photography, it was relatively easy to accidentally make a multiple exposure -- use the same photographic media to record two or more pictures -- because cameras did not automatically change the plate they were using; the photographers had to remember to do that. Photographers also had to carefully repackage the exposed plates as they were taken from the cameras and then be sure to chemically fix them in a darkroom to protect their images from light. So if a photographer left a plate in a camera for two exposures, or if they accidentally loaded a plate they had used once already, they would get a double, or multiple, exposure of the same plate, each time adding new details to the picture on the plate.
In a multiple exposures, each new image that is exposed to the plate will have it's lightest parts overwrite the dark parts of a previous exposure. Dark parts will not overwrite lighter parts, because the chemicals in the plate react to light, not dark... so as multiple exposures are made, the lightest parts of each scene are recorded, and the darkest parts are slowly overwritten. The important thing to remember about this process is this: a dark area cannot erase a light area, and a light area will always erase a dark one.
A long exposure happens when a plate is exposed to a scene for a long period of time, allowing the possibility for objects in the scene to move. In the late 1800's many cameras needed an extended amount of time to take a decent picture... people would have to sit still for around ten minutes for a portrait (sometimes longer!), so it wasn't unusual for photographers to use a brace to hold a subject's head in place so they wouldn't move; and people rarely smiled for these shots, because their jaws would start to hurt due to the length of the exposure. In fact, because of these long exposures cameras were more commonly used for photographing dead people: they would sit still! Objects moving through the scene during a long exposure might be recorded in multiple different spots on the final plate, or only have the brighter parts of the figure captured as the rest of the image filled in with the non-changing part of the scene.
An experiment with long exposures, 1895 [Larger version here]
The example above was produced in 1895 by two experimenters with the Society for Psychical Research, who were investigating a possible ghost photo taken the year before (follow the 'See Also' link at the end to read about that photo). A camera was set to focus on a chair for a long exposure, presumably upwards of an hour (the picture they were trying to duplicate had been exposed for an hour); partway through the designated time, one of the researchers walked into the shot, sat in the chair, and proceeded to move his legs for about 30 seconds... after which, he stood up and walked out of the shot, leaving just the chair again. This produced the photo above, which shows the lightest parts of the figure that sat, while completely missing the legs because they didn't stay still long enough for the light on them to make an impression on the photographic plate.
The Tingewick Exposure
So... is the photo of the Tingewick dog an example of either a multiple exposure or a long exposure, as many skeptics state? The answer would appear to be 'no', and for a very straightforward reason. Have a look at the dog again:
Detail of the Tingewick dog [Larger version here]
Remember that in both a long exposure or a multiple exposure, dark parts are overwritten by light parts but light parts are not overwritten by dark. If the photo of the Tingewick dog was due to either a long or multiple exposure, the animal's dark body would not be blocking the lighter details from the woman's chair! Whatever the animal was, it was in the shot with the rest of the figures when the picture was taken.
As a further point on this particular issue, there is also no reason to believe that Springer's camera required a long exposure for its pictures to begin with. By 1916, several box cameras were popular with enthusiasts both because they were reasonably priced and because they had short exposure times... most cameras had exposure times of as little as 1/25th of a second. Given that Springer took several shots of the tea party, and that the women are smiling and the maid is standing in a position that would be very uncomfortable to hold for a long time, it's most likely that Springer's camera had short exposures.
One Last Strange Discovery
With the full background story of the photo of the Tingewick dog now told, and having examined the main proposed explanations for the anomalous dog in the image -- photoshop, double exposure, and long exposure with a walk-in -- it appears that the picture is still genuinely anomalous. Of course, skeptics can always simply accuse Arthur Springer of creating a fraudulent photo... but they will still have to explain how the photo was created.
Let me add one more oddity to the list while we're looking at the Tingewick dog; something I noticed after receiving the high-quality copy of the image from the Fortean Picture Library. Look:
A head? [Larger version here]
It's not very distinct, but there appears to be faint traces of a transparent head in the picture!
What was the Tingewick dog? It's usually described as a ghost, but that presupposes that it's the spirit of a dead animal... all we have is one strange picture, one moment in time when something appeared where it shouldn't have been, and not completely.