Templot Club Archive 2007-2020
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posted: 27 Oct 2014 22:39 from: DerekStuart
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Hi all I don't know if this is the most appropriate sub-forum, as it isn't an issue with Templot I don't think. I downloaded a map from old-maps.co.uk it is 1928 and thus produced by tape measure and not aviation or satellite of course. The proportions of everything is remarkably close in respect of each item, but the overall scale is highly questionable- to the tune of about 8%. This seems quite high, even for such an old map. (I am comparing this against bing maps which zooms quite close in and has a good scale, whereas google maps does not.) I have printed out the old maps as a PDF and then scanned it as a jpeg to use as a backdrop. When I used the scale of 2500, it was about double so I dropped it to 1250 and thought "oh well". I have since had to change it to 1:1106.226 to get the scale to what I believe to be right when compared to bing maps. Has anyone else any experience of old-maps.co.uk? Would anyone else have an opinion on whether my choice of going with the satellite drawn bing maps is a good one or not? Unfortunately, the area has changed so substantially that I cannot use bing maps directly as a backdrop. Thanks Derek |
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posted: 27 Oct 2014 23:12 from: Martin Wynne
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DerekStuart wrote: I have printed out the old maps as a PDF and then scanned it as a jpeg to use as a backdrop.Hi Derek, When printing the PDF did you change the scaling to None / 100% ? This is not the default setting in most PDF readers -- they scale it up or down to fit within the paper margins. A change of 8% would be typical. This causes lots of grief when trying to do accurate work with PDF files. If you use this PDF reader (free for non-commercial use): http://www.tracker-software.com/product/pdf-xchange-viewer you can extract and save images from within PDF files directly -- there is no need to print and re-scan them. regards, Martin. |
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posted: 29 Oct 2014 02:30 from: DerekStuart
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Hi Martin Yes I did do that. Both when printing out in PDF on the A3 and then when scanning back in. I will try the above link tomorrow. Many thanks for your continued help. |
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posted: 29 Oct 2014 11:29 from: Alan Turner
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Old County series 1:2500 scale maps unfortunately do not have the national grid printed on them (post WW2 maps only) which makes scaling a problem. This is how I do it: Go to a modern map (preferably a 1:2500 but can be any scale within reason - Google maps has a nice distance measuring function now so you can use that) and identify two points that are both shown on the old map and the new map. Measure the distance between the points on the new map and determine the actual distance. Measure the distance between the points on the old map, and knowing the actual distance, calculate the scale of the old map. You can then work out the reduction/enlargement needed for the old map. This is good enough for model work but strictly as the map projection of the old County series maps and modern maps is slightly different you can't use this if you are planning a new road! regards Alan |
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| Last edited on 29 Oct 2014 11:30 by Alan Turner |
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posted: 29 Oct 2014 16:16 from: DerekStuart
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Hi Alan That's just what I did- I took a sample point of about 900 ft and scaled the imported old-maps at a bizarre 1106.226. Being drawn in 1928, whilst I am sure that the larger parts- such as the distance from turnout A to bridge B 1/4 mile away are going to be accurate, the individual buildings are not going to be too clever compared to modern satellite/aerial photography. Oddly btw, bing and google disagree on scale, but I've gone for bing because it zooms in further and has a more clearly marked scale. BTW in terms of buildings, I am assuming railway related buildings were built to fairly common sizes/ designs across a region- so would it be reasonable for me to find a similar existing one (being NER, I'm sure the NYMR is a good start point) or are there infinite combinations? Again, thanks for the suggestion. |
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