• Ultraviolet Photography
  •  

Foxing in a 188-year-old book


10 replies to this topic

#1 Andy Perrin

    Member

  • Members(+)
  • 2,485 posts
  • Location: United States

Posted 12 March 2016 - 18:32

I picked up an 1828 copy of "THE NEW UNIVERSAL LETTER WRITER; or, complete Art of Polite Correspondence: containing A COURSE OF INTERESTING LETTERS, on the most important, instructive and entertaining subjects, particularly [it goes on to list the subjects]." The paper is quite discolored by foxing, which is brownish age spots on old paper caused (depending on whom you ask) by either the rusting of iron particles in the paper, or some kind of fungus growing on the paper. Of course I had to take multispectral photos of it to see what happens to the foxing!

Here is the book itself (iPhone 6S+ pic, taken much later after the sun had moved):
Attached Image: The New Universal Letter Writer.JPG

Here is a page in visible light (iPhone 6S+ pic):
Attached Image: Foxing vis iPhone6S+ small.jpg

Same photo, desaturated in Photoshop, for comparison to the UV and IR pics below:
Attached Image: Foxing vis iPhone6S+ desaturated small.jpg

UV pic (UG11 2mm/BG39 2.5mm, sunshine through window, Novoflex Noflexar, ISO800, F/16, 1/5")
Processing: PhotoNinja, 1-click white balance on an un-foxed bit of the paper, detail slider 5, and some fiddling with exposure slider.
Attached Image: Foxing UV11andBG39 Noflexar F16 iso800 small.jpg

IR pic (nominally 1000nm off-brand eBay filter, sunshine through window, Novoflex Noflexar, ISO100, F/16, 1/5")
Processing: in-camera WB on a new piece of white paper; PhotoNinja: detail slider 5, and some fiddling with exposure slider.
Attached Image: Foxing IR1000 Novoflexar F16 iso100 small.jpg

Edited by Andy Perrin, 13 March 2016 - 05:52.


#2 nfoto

    Former Fierce Bear of the North

  • Owner-Administrator
  • 2,361 posts
  • Location: Sørumsand, Norway

Posted 12 March 2016 - 19:08

Interesting and not entirely unexpected results. Some years ago I did an assignment on shooting ancient scrolls from the Dead Sea caves. IR around 900 nm gave very readable results from scrolls so blackened and weathered over the millenia as to be almost jet black.

#3 colinbm

    Member

  • Members(+)
  • 1,344 posts
  • Location: Australia

Posted 13 March 2016 - 02:05

Thanks Andy
Have you tried this with other lower band pass IR filters ?
Col

#4 Andy Perrin

    Member

  • Members(+)
  • 2,485 posts
  • Location: United States

Posted 13 March 2016 - 03:15

Nope, but I can have another go tomorrow when the sun comes back! I have a 720 NEEWER, an 850 NEEWER, and a 950 NEEWER (all long pass). Also a couple of IR bandpass filters from Omega (905AF30, 830DF30).

Edited by Andy Perrin, 13 March 2016 - 03:26.


#5 colinbm

    Member

  • Members(+)
  • 1,344 posts
  • Location: Australia

Posted 13 March 2016 - 04:48

Thanks Andy
I'll look forwards to the results.
Col

#6 Cadmium

    Member

  • Members(+)
  • 2,891 posts

Posted 13 March 2016 - 09:25

Andy, Very interesting! Nice results. Thanks for the post.
Here is a link someone sent me, it may relate in some ways.
http://heritagescien...6/2050-7445-2-8

#7 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 7,456 posts
  • Location: USA

Posted 13 March 2016 - 16:39

Andy, this is a great post. I've seen foxing on old books, but did not know anything about it or know the name 'foxing'. So I followed some links last night and learned more.

My entire life I've been "allergic" to handling old books. My hands get really really dry and a little itchy from paging through old paper. The one benefit from this allergy is that this has made it easy to keep my book stacks to an acceptable size. :D Anyway I'm voting for mold being an issue rather than iron oxidation. But who knows.

I think that I will move this post to the Forensics section. It fits there perfectly. :D
Andrea G. Blum
Often found hanging out with flowers & bees.

#8 enricosavazzi

    Member

  • Members
  • 515 posts
  • Location: Borgholm, Sweden

Posted 13 March 2016 - 18:00

View PostAndy Perrin, on 13 March 2016 - 03:15, said:

Nope, but I can have another go tomorrow when the sun comes back! I have a 720 NEEWER, an 850 NEEWER, and a 950 NEEWER (all long pass). Also a couple of IR bandpass filters from Omega (905AF30, 830DF30).
No need to wait for the sun. The light of conventional, low-power incandescent bulbs (60 to 100 W) is mostly NIR. The only problem (for us NIR photographers) is that these bulbs are being phased out in most countries or, for some low powers, already have been. I already have a stash of 60W bulbs known to perform especially well, although they are still available in shops. It might be a good idea for other NIR photographers to do the same.

Halogen bulbs emit a lower proportion of NIR to VIS. Still usable, but incandescent bulbs are better.

Some heat radiators enclosed in "quartz" tubes that glow red when powered on might also be useful NIR sources, but I have not tested them. We cannot use thermal IR for imaging, of course, but the fact that these sources glow red suggest that they also emit a substantial amount of NIR.

Edited by enricosavazzi, 13 March 2016 - 18:00.

-- Enrico Savazzi

#9 Andy Perrin

    Member

  • Members(+)
  • 2,485 posts
  • Location: United States

Posted 13 March 2016 - 22:31

I needed to wait for the sun because the other pics were all taken with sunshine, so for them to be comparable, the new ones had to be done under the same conditions. I actually have an "old fashioned" incandescent flashlight that I use for NIR photos on rainy days, but in this case I'd already started with sunshine, so to the sun I had to return. New photos will be up later (I took them, but I have to process them.)

View Postenricosavazzi, on 13 March 2016 - 18:00, said:

Some heat radiators enclosed in "quartz" tubes that glow red when powered on might also be useful NIR sources, but I have not tested them. We cannot use thermal IR for imaging, of course, [...]
Hah, speak for yourself! (I know what you mean, I just can't resist being a smartass.)

#10 Andy Perrin

    Member

  • Members(+)
  • 2,485 posts
  • Location: United States

Posted 18 March 2016 - 18:50

Sorry for the delay. Work intervened.

Anyway, the results of using different IR bandpass filters were actually not very interesting — I think one would have to go some way into the visible spectrum to find where the foxing actually fades out. I tried the 720nm long pass, the 830DF30 bandpass, and the 905AF30 bandpass. The latter two were identical (except for exposure time and so forth). The 720 was interesting because it has a bit of color, which revealed some differences in the part of the page where the text is relative to the margins. In all of them the foxing was gone.

All images were taken with the Novoflex Noflexar with sunlight through the window (which probably makes no difference for IR).

Processing was in PN. Details 5, Contrast 10, Saturation increased to 30 for all colors in the case of the 720nm filter, and exposure/illumination adjusted as necessary. White balance was off a white piece of paper, in-camera.

These bandpass filters were quite tiny (26mm) and unthreaded, so I have mounted them with poster putty, which leaks a bit of light at the edges.

720nm long pass NEEWER filter, F/8, 0.01", ISO100
Attached Image: Foxing 3 IR720NEEWER Noflexar F8 0.01%22 iso100.JPG

830DF30, F/8, 0.16", ISO100
Attached Image: Foxing 1 830DF30 Noflexar F8 0.16%22 iso100.JPG

905AF30, F/8, 0.8", ISO100
Attached Image: Foxing 3 905AF30 Noflexar F8 0.8%22 iso100.JPG

Edited by Andy Perrin, 18 March 2016 - 18:54.


#11 colinbm

    Member

  • Members(+)
  • 1,344 posts
  • Location: Australia

Posted 19 March 2016 - 01:17

Thanks Andy, It is good to see that the 720nm long pass NEEWER filter works just as well.
Col