Photographing old maps

Chataigner

Chataigner

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David
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I have an opportunity to photograph the Cadastre Napoléonien (Napoleonic land registry maps) for an historic town in France. The pages are huge, about 1m by 70cm and covered in tiny hand drawn symbols and names - it's going to require huge resolution to reproduce the detail.

My rule of thumb says around A3 is the limit for a 10Mpx image to get any detail - a 12pt character requires about 20px to reproduce adequately so around 100px to the cm, thus 4000px for the 420mm of an A3... is this making sense ?

If this is indeed the limit, I will need to take 4 shots per page - possibly more and there are nearly 100 pages.

Does anyone have experience of this kind of thing ? Advice please !
 
I should add that I have a suitable space with no natural light and some cool studio lights with diffusers. Supporting the camera exactly above the documents is no problem - the one big issue is resolution. I will shoot RAW to prevent the camera from applying any compression.
 
What are you doing the photography for?

To be printed or just viewed digitally?
 
Hello David nice to see you here from 'the haven' :)

Think that is the key really - what the pictures are for.

Resolution needed kind of depends on what you plan on doing with the images. You don't view a large image as close up as you do a small one when printed. look at the detail in an advertising hoarding to see that in action.

Not checked your maths but if you are after maximum detail then I would have thought multiple images and stitching them together afterwards with panorama making software would be the way to go if you need to reproduce an exact copy.

A macro lens will have a flat focus plane not spherical like a standard lens which would help with focussing.

Maybe spread a newspaper sheet out to the same size and try it out before hand. If it is nearly good enough as a single shot can you borrow a higher MP camera like a 5D2?
 
fixedimage said:
What are you doing the photography for?

To be printed or just viewed digitally?
Click to expand...

Both. The original is far too fragile to be handled regularly so it is currently locked away. We want to create a copy that can be accessible to all using prints, perhaps not full size but maybe A1. Since the smallest detail is around 10pt characters, but on a metre wide page, if we shrink it too much the small detail will become illegible.

We also plan to put the images on line. For this I propose thumbnails of the whole pages linking to full res. images of smaller bite size sections corresponding to the shots we actually take.
 
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Last time I did anything like this,it was with a big rail camera,with 16x12 film vacuum to the cameras back,to get as much detail as possible,I am not sure how you would go about in the digital world,the big thing is how to get the maps as flat as possible,and getting the lighting right,maybe think about hiring a studio for the day :)
 
RobertP said:
Hello David nice to see you here from 'the haven' :)
Click to expand...
Thanks to your suggestion Robert !

I note that you have posted here once or twice before :lol:, does that mean that woodwork is not your overriding passion ? :'(
 
I do spend more time now on woodworking but photography came first :)

Do try some test shots with newspaper or something similar. You might be surprised with the detail in a single image. Check the corners when you do it as most lenses are not as good away from the middle and they also have an aperture sweet spot for best sharpness (usually around f8).
 
Well you certainly seem to have a handle on the type of resolution you need to resolve the fine detail.

Sounds like a big job but an interesting one and I'm sure once you get started you'll settle into a systematic way of working and it'll go pretty easy.
 
Absolutely, a big scanner would be ideal, but these chaps are bound into "books" with solid oak iron studded covers and massive locks. The weight is around 30-40kg per volume ! :bang::bang:

...however, I've done some tests as suggested and it looks as though we might get away with three shots per page. Here are the results, these are sections cropped from shots of a newspaper, top one is from an A3 full frame, next one is from an A2 full frame and the bottom one is from the full cadastre page size at a bit over 1m wide.

The results are actually better than they look - firstly the display you see this on has lower res than the real image and secondly the quality of printing of the newspaper really is that bad, the top image is absolutely bang on - it really does look like that !

resolution.jpg


Will try it for real next week. Wish me luck !
 
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If those are from the corner then its not bad when you consider normal viewing distance.
 
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