I seem to recall there being an article I read not all that long ago that dealt with figuring out the scale of a photo so that accurate measurements could be determined from the photos.  I'll try to remember what and where it was exactly.

it seems to me though...if you know, for example, the  "proto" size of the window in the picture if you measure the window in the photo you should be able to determine a scale from that and figure out the rest from that, not?

Maybe I am oversimplifying this and missing a problem.  Am I?

 

 

The "standard" height of "people" doors is now 6 ft-8 in. I think this would be a measurement that can work in most cases - would be a lot simpler than counting rows of brick

Hope this might help.

 

The bricks measure 2.5 inches thick.  The mortar is @ 3/4 inches thick, but I don't know if that is a standard or if it is just a matter of staying consistent with whatever thickness of mortar that you start with on the first course.  I suspect that going off of the standard door or window size would be more accurate.

rtw,  

Some thoughts regarding your problem.

-Bricks can vary greatly in size, depending on type, use, era, and region.  I have 50+ year old bricks that now have a new life as a garden path.  They are (8"+/- ½") x 4" x 2½" thick.  But my 1972 fireplace has bricks (exterior, not firebrick) that are 3½" thick, with the grout lines at 3/8" to 1/2".

-You've got a good tool to make a scale:  your horizontal dimensions.  But due to distortion based on angle, you will want to use your "scale" at the same point on the wall that your horizontal dimension was taken.  For instance, if you know the width of a window, measure that distance on the photo, then set up a ratio.  Then use that ratio to determine vertical dimensions, only in the vicinity of the window.

An example:

Say your horizontal dim = 3'8½" (44½") and photo width dim is 5/8".  So 44½ divided by 5/8 = 44.5 / 0.625 = 71.2.

Now, multiply all of your photo measurements by 71.2 to get the actual dimension in inches.  (You only need about 3 digit accuracy, even though your calculator may give you a long string of digits.                                                              If you get 71.8734578563, use  71.87, or round to 71.9, it will work OK.)

-Those are double hung windows.  In my experience with older homes with DH windows, many of them are the same size.   When they are larger than the rest, it's usually in the horizontal dimension, with the vertical remaining the same.  Bathrooms and kitchens are usually different.

For high camera viewing angles, like the chimney, all bets are off,  the angular view will skew your scale.  But in the case of the chimney, having determined the height of, say 20 or 30 bricks in a few other locations, you can use the average height of 20 or 30 bricks to figure the chimney height, and the height of the roof ridge, and the dormers.

Oh, this is such a fun part of the hobby.  When you're done, then you'll think it fun!    I wish you well.

I am spent the last 10 years or so doing Arch Design and measuring up buildings. In general we go as follows. Your average door is 6'8" high. So you can look at how many bricks equals the height of the door if you can see that. But in general in Residentail arch bricks are modular by this I mean that one brick plus one joint wide equals give or take 8" for height this works out to three bricks plus three joints equals about 8" this way you can turn three bricks on thier side and take up the same space this allows for a lot of fancy brick work. So in general 1 brick wide or three high equal 8". Some are different but this is the so called standard brick. Now this may not be 100 percent perfect and I have had issues with this but you are not trying to make the floors of an addition meet up with the existing building you are just trying to get something that looks right. So this should work for you. Also keep in mind that the common slops for a roof are 3/12 4/12 6/12 8/12 10/12 or 12/12 (3/12 is not used much anymore) they are not alwas used but more often then not Also windows tend to be 6'8 from the floor. So with all this info you should be able to make a reasonable guess at the building you have the photo of. Out in the field I tend to take the hights of the windows and doors and to take the size of the bricks in two or three locations to get and average. It is amazing how often I have had to look at a photo and count bricks! Doug Meyer South Lyon Mi.

Another consideration when modeling a real structure is to aim for it to "look right" rather than trying to make a super accurate model. If you include the need that many real structures have to be selectively compressed to fit a model scene properly, and you realize that in many cases, a facsimile is fine.

If you think about it, how many people will look at your house and go - you made it 4 feet too short! Nobody, that's who.

Thank you to all who replied.  I was talking to a friend in our operating group and he said that it can be done in 3rd Plan-it(tm).  I've got the software and I'm just learning how to use it.  He said that if you have the measurements to a known item (say a window) you can "frame it" and then adust the scale to the scale you're using (in my case HO) and then use the "measure" function to measure other distances.  I do have the exact measurements of some of the windows, so I can probably use that technique (once I learn it) to do the measurement.  I also like the idea offered of "what looks right"

I plan on documenting the project for later sharing as a "how to" - if it turns out well.

Rick

The latest issue of RMC (April 2010) has a nice article about converting a photo to a scale drawing using Google's free SketchUp program. Might be worth a look, some of the ideas might apply to other software.

Chris

Chris,

Thank you for the suggestion - I'll check it out.

Rick

Don't forget to add the 1/2 inch for mortar between each layer of brick. Measuring brick is fine but don't leave out the Glue layer

Dan