Ghost photo puzzle

I don't normally pay much attention to ghost photos, but courtesy of the SPR Facebook page, here's a discussion of one, taken at Eynsford Castle in Kent, on Robert Lea's blog:
http://skepticsboot.blogspot.co.uk/2018/...nable.html

The puzzling thing is that his explanation rings true - that the "ghost" is just a window or door in the stone wall of the castle - but its position doesn't seem to match that of aperture he found in older photo of the same wall. I assumed there must be another aperture in the right place, which was obscured by another wall in the older photo. But then I found a third photo of the unobscured wall, and there was no such aperture there. So I'm not sure what to think.






(detail from https://irp-cdn.multiscreensite.com/aaf7...80x960.jpg)

[Pollux]

I made a a few zoomed-in examples of the picture - with some sharpened, auto-adjusted, gamma, and invert-adjustments - and whatever it it is, it doesn't look like an door opening.

It's not an aperture, the image is forward of the wall somewhat. As I find it hard to accept that "ghosts" (which whatever their origin I believe in) ) can be photographed, if the film hasn't been cleverly tampered with, then I'd go for someone mucking about (dressing up). I don't know why anyone would do that though, but some people would.

And then again it might be what it appears to be. Just my thoughts but it is interesting.

I posted a couple of comments on the blog, but Robert Lea is still convinced it's the aperture he found in the older photo. The position seems wrong to me, but whatever it is I'm very sceptical about ghost photos.

It happens that I live not all that far from Eynsford, so when I get a chance I'll try to go and take some photos. It shouldn't be hard to tell whether his solution is correct.

The second photo was taken at a different angle than the first, but you can see the top of the niche or whatever it is (the dark object) to the right of the stairs in the second photo. If the photographer moved to the left and took a picture the dark object would be centered behind the stairs.

Look at how the right edge far wall lines up with the wall at the top of the stairs and you will see the two photos are at different angles.

Yeah I noted that first time but even allowing for it, I can't seem to make all the reference points in the background line up right. Pollux's pictures also seem to indicate that the image is not an indentation. Blowed if I know.

I would like to know the focal length of the lens used in each photo.  You can stretch or narrow the background with respect to some point in the foreground by using different focal lengths or by taking the picture at a different distance.

The second photo was taken at a different angle than the first, but you can see the top of the niche or whatever it is (the dark object) to the right of the stairs in the second photo. If the photographer moved to the left and took a picture the dark object would be centered behind the stairs.

Look at how the right edge far wall lines up with the wall at the top of the stairs and you will see the two photos are at different angles.

Thanks. I did realise that was the idea, but I don't think it's correct. 

I adjusted the photos so that the scales were about the same and put them together. It's not hard to match details of the stonework in the two photos. In particular I've circled a distinctive pattern just to the right of the aperture in the older photo. That makes it clear that in the new ("ghost") photo the aperture is behind the wooden railings:

Note that, although the angles of the photos are slightly different, they don't differ by very much, because the foreground wall is a long way away from the background wall. I've indicated roughly the line of sight here: