The second one looks like its just a trick of the light. We're dealing with low quality black-and-white photography here and I can guarantee you that you will always find patters in something like that, human brains are really good at finding apparent patterns where there aren't any (hence all those Jesuses appearing on tortillas). In fact the "face is so indistinct and hard to make out that it took me quite a while to find it even when I knew roughly what I was looking for.
I'd be willing to bet that the third one is a smoke plume, or at least the "head" is. The way smoke looks and behaves allows you to see pretty much anything in it (like the many people who saw the face of Satan in the smoke coming from the World Trade Center).
The first one does look like its genuinely "authentic" in the sense that it isn't a trick of the light or just some weird pattern that vaguely resembles something, but personally I'd put my money on it being some sort of hoax.
Yeah possibly, in the case of the monk however, it was just a vicar in a new parish taking pictures of the church,with absolutely no motive for creating a hoax
Other than say, attracting people to his church, certain amount of fame, or generally just to be interesting or even to make fun of people. There are plenty of motives for something like this.
Today it is! The posted 3 were taken and published long before photoshop. Not saying they are definitely genuine but lasting this long without being totally debunked is impressive
It's precisely because there was no photoshop back then that these things were seen as believable. Most people simply didn't understand how photographic film could be manipulated to produce images like this. And I think its pretty much impossible to totally debunk something like this, unless you get a confession from photographer that he deliberately manipulated the photo or an eyewitness account that the "girl" was in fact just a plume of smoke, or unless someone finds a really obvious sign of manipulation (not likely unless its something totally obvious like Stalin's earliest attempts where he just had people removed from photographs leaving a gaping hole. He'd get a lot better at this later on). There will always be people who believe in it, and quite honestly, there's no way you can convince them.
Sorry, I'm just extremely skeptical when it comes to anything super-natural