with a film camera, if the film doesn't advance properly then a new picture can be shot over an old picture. While I'd like to believe its a picture of his son watching over them, I suspect it is more likely an old fashioned double exposure. His last picture before this one was probably one taken of his son before the tornado.

I'm going to argue against that because the father or other family member would surely have remembered taking a photo of his son in the same red shirt he was buried in.

What are the chances the guy was using a film camera? About 20%, I'd guess.

I teach a class where I have to keep track of the percentage of people using digital just-about-anything and it was projected that about now we'd be at 80% of the market using digital cameras over film. Film is highly prized by the more artsy photographers and it's still very much alive.

Here's a figure for Britain from a 2012 article:

Figures show that 80 per cent of us use a digital camera or camcorder, with 40 per cent relying on them exclusively.
This compares to the 45 per cent who use their smartphone.

http://www.telegraph.co.uk/technology/news/9361867/Digital-camera-sales-slump-as-people-use-smartphones-to-take-snaps.html

My other reason for thinking it's probably "real" is that I don't think this type of thing is that unusual. I don't want to say I take photos of ghosts "all the time," but I have had quite a number of apparitions show up. My last one was during Sandy, when I posted here about the African-American soldier on the side of my property.

And one other thing--if you read the statistics for people who have reported an experience of someone close to them who has crossed over and then reached them in some way, it's actually quite high. I can't recall that figure off the top of my head but it's very high for couples. I would think it would be similarly high in a parent-child relationship.


Cher

and apparently even without photoshop.

I didn't want to go into photoshop because that would be accuse the father of trying to pass off a fraud, although that possibility does sadly exist it.

But it turns out that double exposures can also take place with digital cameras. There are cameras that have that as a feature, in which case it seems entirely possible that the feature could have been used accidentally.
I know I've accidentally changed camera settings when taking specific photos without realizing it at the time.

http://www.digitalcameraworld.com/2013/05/30/double-exposure-photography-how-when-and-why-youd-want-to-turn-two-images-into-one/

Not many cameras have that feature, so I think it is far-fetched to think this happened. So first the guy would have to have a camera with this function--not real likely. Second, he would have to accidentally re-set his camera to do this type of double exposure. That both these conditions are present is not impossible, but the odds aren't good.

I also don't think a parent is going to Photoshop something like this. Sure, it could happen. It would be tantamount to that rare student who tells you his mother died so he can get a reschedule date for a test.

Yes, there are people who do this--thankfully, they are few and far between.


Cher

although if the father comes out with a book, I'll amend that opinion.

I don't have any data on how many cameras offer multiple exposure capability, so have no opinion on that likelihood. Although since the father was already using special options for night photography, it seems entirely possible his camera is one of them, imho.