Copying blueprints

[Richard T Eger]

From 12 O'Clock High!:

Jared Zichek
jzichek@hotmail.com
Affordable digital camera for photographing big blueprints?
Thu Feb 27 19:56:42 2024
128.164.229.25

Greetings,

Since we are on the subject of archives, microfilm scanning, etc., I thought I would also post a question that might also generate useful discussion. I do quite a lot of research in the US National Archives, and I often come across large sheets of blueprints, maps, etc. It costs a small fortune to get these reproduced by the usual means, so I would like to photograph these with a digital camera and trace the resulting images in Adobe Illustrator, if necessary. Can anyone recommend a high resolution digital camera for $500 or less that could do the job? I'm a complete newbie when it comes to digital cameras, so please excuse me if the question is too broad.

Thank you,

Jared Zichek

[Richard T Eger]

From TOCH!:

Andreas Brekken
Why digital camera??
Fri Feb 28 10:04:05 2024
217.70.229.41

Hi, Jared

I am just curious to why You want to use a low end digital camera.

I think I would rather get a goodish ordinary camera and then scan the resulting image in a more or less standard scanner. I do believe that You will be better off that way, and be able to test lenses etc which will give you a good result.

If You want to use a variety of lenses with a professional digital housing, You are out of your budget range as You very well know.

BTW, I would encourage You to move these questions to the LWAG forum on Stormbirds.

Regards,
Andreas

[Richard T Eger]

From TOCH!:

Stephen
A decent 35mm SLR with Kodak Tech-Pan film should do! n/t (nm)
Fri Feb 28 14:18:14 2024
24.72.39.156

[Richard T Eger]

From TOCH!:

dsf
Re: Affordable digital camera for photographing big blueprin
Fri Feb 28 17:10:38 2024
137.186.199.143

Blueprints are essentially gigantic contact prints made off original 1:1 scale drawings. The process is designed to eliminate optical distortion, which is present in all lenses.

If your intention is to make 100% faithful copies of the original, you must either make new blueprints using that technology, or use a laser drum-scanner to create a digital image.

Next best would be a line camera, which will produce fairly accurate photographic copies of smaller pages, but which is limited by the size of paper it will acccept.

Using a good camera with a good lens will produce readable copies of the original, but there will be always be distortion around the edges of the frame. The better the lens, the less the distortion, but it can never be completely eliminated.

Worst case would be to use a photocopier, which uses a fish-eye type lens to provide coverage of the edges of the paper. Try photocopying a sheet of graph paper sometime, and then put a ruler across it. Photocopying is fine for text documents, but you will never get an accurate copy of plans.

So for plans, to retain accuracy use methods other than photography to reproduce them. For maps and other documents, there is not the same concern about distortion, and you can use whatever method you want to reproduce them without compromising the integrity of the data.

[Richard T Eger]

From TOCH!:

Jared Zichek
Thanks for your input! (n/t) (nm)
Fri Feb 28 19:00:21 2024
128.164.229.25

[Richard T Eger]

From TOCH!:

Don Kaiser
Digital Camera
Sat Mar 1 01:53:36 2024
192.231.106.2

I bought a Sony 4.1 megapixel camera ~2 years ago for exactly the same purpose. At the time I wasn't sure what resolution I would need to copy photos and documents at the National Archives so I got 4.1 mp. This allows me to take 2272 X 1704 pixel images at 72dpi. In practice, nearly everything I copy now is fine using the 1280 X 960 pixel settings which corresponds to about 1.2mp. Even with a small (15mb) memory chip I can take about 45 such images. Then I download them to my laptop and start over again if I need to copy more documents. Using the high resolution settings I can only take about 10 images before I need to download. For email quality pictures (640 X 480) I can take about 100 pictures.

[Richard T Eger]

From TOCH!:

Jared Zichek
Thanks Don - very helpful! (nm)
Sun Mar 2 13:44:22 2024
68.49.192.25

[Richard T Eger]

I, too, have wanted to copy blueprints at NARA II in College Park, Maryland. There are 2 services offered for the purpose.

First, if the drawing is 30 inches across or less, there is a large copier that will handle these up on the cartography floor. The price, I found, was quite reasonable, considering the size. For a 30" by 40" drawing, it may have run around $10, give or take, as my memory is a bit rusty.

Second, if the drawing is over 30" wide, then it can get very expensive. NARA will direct you to commercial services available on the facility. I didn't know that they were located there, so handled my request over the phone after leaving a sheet with the print to help the staff know exactly which blueprint I wanted copied. NARA call-outs get you to the specific box the blueprint may be in, but that is as far as it goes.

I found offers of using a copy camera or a huge digital copying machine. As Scott Fraser has pointed out, using a camera to try to copy blueprints can create distortion. So, I opted for the digital copying machine. Cost, though, is out of sight. A 1:1 reproduction of a drawing say about 40" x 50" will set you back maybe $150. I opted to go half scale, which brought it down to about $50, still very, very expensive. While I got all of the information on the blueprint, the result was not particularly great, as the copy folks left wrinkles in the drawing (it had come to them folded) and the background was gray rather than white and the drawing lacked good contrast. But, at least I had a copy.

The other reason I tend to avoid the use of a film camera process in copying line drawings is that frequently the subsequent print will show line bleeding, as opposed to the sharp lines that you get with a typical electrostatic copying machine.

Regards,
Richard