I wonder if it’s possible to get accurate measurements from photos when scratchbuilding? Are there any secrets behind this that I can use?
Well, most doors are 6’ 8", so you can start from there. That’s OK for modrn times, but might not apply for past times. You can also ballpark a person at 6’, and measure from there if one is standing close to the building. I’ve used both when scratchbuilding from old photos. As for rolling stock, it’s probably easier. For example, if you can see a freight truck wheel, you know that’s generally 33" in diameter.
Find a COMMON ITEM in the picture, Piece of wood trim, cinder blocks and bricks are GREAT. The key is that IF the item is at an angle a little trig may be needed to get on the money.
Hope this helps and makes sense.
George P.
(doing the same thing)
If you have good square-on photos, you can build somethign accurate enough to stand up to measurements. If you have photos only fron angles, you can still build something that is close and certainly looks right, but it might be tough getting things exactly perfect.
Then there’s always the details - are you going to scratchbuild exact windows or pick some Grandt Line ones that are close? Likewise, are you going to worry that the width of the building actually was 20’ 6.5" and your model comes out at a scale 19’ 8"? Probably not… but some people do want nothing short of perfect.
If you are taking the pictures yourself - make a ‘story pole’ with alternating colors at various known measurements and lean it up against the structure before taking the picture. That way you will have a very accurate guide when later looking at the photo.
–Randy
For photos that are on an angle the measurements can be estimated by finding the vanishing points (where extending the two parallel sides of an object would meet) and measure down those lines. Remembering that the measurements are non-linear. That is they get smaller the further away they are.
It also helps to know if the photo was taken with a wide-angle, normal, or telephoto lens as that effects compression.
Short answer: Not easy, but doable.
Chip’s right. if the camera is tilted to the plane of measurement, you have to determine whether it is tilted in one dimension or tilted in two dimensions. If one, you have to apply trig once, if two, some measurements require applying trig twice.
Once past that, you can get pretty close, depending of course, on the resolution and size of the photo, and the presence or absence of known dimensions to start from.
I agree with and utilize the same methodology outlined by Dave Vollmer in the first response to the question. I think you’ve probably seen examples of my scratchbuilding efforts in the Weekend Photo Fun threads. Most of my sctructures are scratched simply from photos I’ve pulled off various websites. With just a little modeling skill it’s really quite easy to do.
CNJ831
How Timely. Some good advice there. I am in the middle of doing the same, drawing the plans to build HO models of the Old Saybrook Station (CT) and Freight House, Get as many photos that you can. A good draftsman’s divider is a BIG help. Look for things that can be verified. If there is clapboard siding, count the rows to the top. Guestimate how many inches to the weather and multiply that. I find that 5, 5 1/2 or 6 inches makes sense. Verify against window panes, door frames etc. Once you are satisfied that the vertical height makes sense use the same units to discover the width. On board and batten siding try 10 to 12 inches spacing and see how that stacks up with the other measutements. Most bricks are a nominal 4 x 8 inches.
I gathered photos of the New London station from the web. There is man in a sailor’s uniform near the front corner of the building. Probably a submariner (the US Navy submarine base is in Groton across the Thames River). Maybe 5’ -8" or so. Verify that against the window dimensions, etc. Then make a scale ruler and and measure everything possible. For line side buildings I start with 4’ 8" between the rails and go from there. Have fun.
I forgot to mention. To make it easier to be more accurate I scan the photo and crop it down to just one part of the building, usually the side that is most dead on if possible. Using Photoshop I rotate the “canvas” to align an edge vertically. Then I enlarge it as much as possible to fit the largest paper my printer can handle. It is much easier to work with the biggest shot possible