Thoughts on using old photographs to size and scale our models:
Posted previously in the photography section. ~ Here is the link:
On the previous site there was algorithm for doing exactly what you refer to when the subject matter was askew. Hopefully someone has a link to that still.
Darren ~ I’m not familiar with that one but would certainly be interested!
Do a shout out bud and you will hopefully get the needed result.
One example from the linked post:
This is the photo I used to start my Mack NO project:
Known dimension: 24 inch wheel rim.
More information recently added to the original link shown above.
Aren’t photos notorious for having some sort of perspective distortion?
Suggest you check the link to the other thread listed above on this same subject and look for this photo.
Yes indeed, it’s an inexact art to say the least. I’m not sure how the above-mentioned algo would work without known data points such as how far from the object & what angle to the perpendicular/profile…but then I was always crap at math. Typically there’s one or more things/elements in a photo – better still a number of photos of the subject - that provide a reasonable estimate of size, which can then be used to estimate the measurement sought.
There comes a point where, if there are no reliable sources and nobody else would know if the guesstimated dimension is a few scale-inches out, why waste time worrying?
I had that problem scratch-building the Anthropoid trailer-tram;
I couldn’t find any original plans or other tech information so all I had was the drawing above (which didn’t actually show the correct trailer version but close enough), and a bunch of period & contemporary photos. I had the driver-tram as a kit & simply compared/converted measurements from it to the trailer & used photos to test my eye/gut as to whether it looked “right” or not. Ideally I’d have preferred to ask my Czech correspondent to measure everything, but I was too lucky already that she was prepared to go to the Prague museum & take photos for me, gratis bless her…
Result:
