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Frustrating that the images are almost-but-not-quite aligned, especially in the foreground. I think that makes it look like the towns have changed more than they have.

What would it take to get pixel perfect alignment in a big image like this? For starters, you'd have to figure out the exact lens and zoom level, and get to precisely the right spot...

2 comments

I was thinking the same and concluded that creating lenses back then probably involved manual work, and were more hand made in general. So the distortion we're seeing is probably due the higher degree of imperfection in the lens sphere shape of the old lense.

But theoretically this could be corrected further using software. If you correct one picture manually, and used the same distortion as a reference for other pictures. Maybe...

No idea if there is software like this anywhere.

"If you correct one picture manually, and used the same distortion as a reference for other pictures"

All the pictures would need to have been taken with the same old camera, though, which I think is not the case here.

Only the camera position is required to get good alignment, lens and zoom level is fixable in photoshop, just crop and scale a bit.

Unfortunately, it's very hard to identify the exact camera position, since alignment of foreground objects can be matched from different positions at the expense of matching the original perspective. Old cameras had huge imaging plates, with low crop factors, I suspect what happens with a lot of these old/new match-ups is that the photographer is standing far from the original spot to achieve "best possible" alignment with the foreground crop - which of course screws up your perspective. You could align against the background, but then you'll have poor alignment on the foreground.

Cleaning up the crop/zoom in photoshop does not help you unless you are shooting from the exact same spot to get the same perspective.

http://www.digitalcameraworld.com/2014/08/15/debunking-the-m...