I ran across a lady who claimed to be able to do time camera and even fairy shots with her digital camera. She posted a 100+page PDF book of her findings just on one picture that went on and on and on... In her case, it was 100% bunk. I'm not saying it's impossible to capture pictures like this, I'm saying her methods were flat out wrong. As a classically trained programmer and someone with a film degree, this is why:
* When zooming into compressed images from a digital camera (JPG in her case), the lossy compressing will create some very odd artifacting in high contrast regions. She was zooming in so far that she was seeing faces in the noise (sometimes only a few pixels wide). Humans are genetically programmed to pick out patterns in noise. It's part of our survival. The noise is by definition part of the CODEC artifacting. To reproduce this test, find a cluttered forest/grove with a lot of trees, bright sunlight behind you, and darkness between the trees going deeper into the woods. Take a very large, least compressed, highest resolution image your camera can do. Go home, load it in your favorite paint program, then save it as image-01.jpg with around 90% compression (that option should be in the save dialog box). Load image-01.jpg and save it as image-02.jpg. Repeat this process for a total of 10 times until you get to image-10.jpg. By now you should be seeing some clear generational losses from the JPG CODEC. Zoom into the high contrast areas (especially by the trunk of a brightly lit tree with a dark background behind it). You will see all sorts of things. You can jump to the in between numbers to see these artifacting patterns changing with each save.
* In her case, she was also doing some digital dark rooming to help bring out the "faces". There's nothing wrong with doing this (so long as your monitor is properly balanced) to help make the subject clearer. The problem is that she was doing this to the first point made above.
* In her case, she was also going through all the different Photoshop filters on the image looking for patterns. There's nothing wrong with this, except she was doing this to the 3-5 pixel wide face mentioned above. Many of these filters ARE SPECIFICALLY DESIGNED to make the image into a kind of artwork. "Line Art" was one of them. There was also (over) sharpen, posterize, pencil, and a bunch of others I can't think of at the moment. She was then finding more and more faces... and getting obnoxiously excited about it. Well, see above.
* If you've got the sun or a bright light source to your back, lens flares and sun dogs won't be much of an issue. If someone over processes an image, these might become visible, esp. off bright shiny objects. These's aren't ghosts or time images. Sometimes the internal reflections off the various glass lenses inside a lens assembly can produce some very odd images at these processing levels.
* Motion blurs... If there's a picture in a dark setting or at night, bugs that we will often ignore by eye sight will appear as streaks in a picture. This has to do with the longer exposure time. These are not interdimensional tears or monsters.
* Quick shots out of focus. Many will claim a ghost or time image with these when they're actually nothing but sloppy camera work and the human brain looking for the patterns mentioned above. "Noisy clutter" in the far distance of a picture can merge to form all kinds of false things.
* A real picture of interest would probably look more like a double exposure. The subject should be dozens of pixels wide at the minimum for clarity.
* Something that might be of interest is to use an infrared pass filter that blocks all visible light. Something might show up in IR only that would get drowned out in the usual visible light. On the flip side, ultraviolet may also produce something of interest.
* There are also some people looking for attention who will make deliberate fakes of the above mentioned. Gotta watch out for them.
I've been working with various paint and image manipulation programs off and on since the early 1990's and have been around the block with these. I've also been working with video encoding since the late 1990's. All the video CODECs used for mass distribution are also lossy and follow the same general guidelines. I haven't done as much video camera work as I should have for someone with my university degrees, but I have worked in a video duplication lab as one of my past jobs... and I've seen a bunch of things that took a few minutes to figure out... and they were all explainable. I'll also take a second to say that video interlacing is pure evil incarnate. Stills from interlaced video has confused many people.
So... if you find someone posting bad images kinda like I mentioned above, move on.
If you happen to find someone with a working chronovisor, you'd better post it here as there will be many who are interested... but still be aware of the points I made above as even a chronovisor could make a false image out of "noisy clutter"