Taking photos of faded grave inscriptions
March 26, 2019 5:01 PM   Subscribe

I've volunteered at my local council to help record and restore some of the historic graves in my local area. There's a bunch of us doing it but I'm the only one with any experience with a camera (and not much at that). Where do I go to research techniques on how to get the most out of very worn inscriptions?

This question was asked in 2010. I'm wondering if there's anything more to have come up recently.

I've had some success with using lighting to highlight the carving, so that's more or less under control. The problem that I have is that we have a LOT of graves where the carving and/or painting is weathered away to almost nothing. Are these a total loss or is there some other way to record the inscriptions before they're completely lost? Some of them have had either lime-based whitewash or lead-based, with the letters picked out in either lead or oxide-based paint. Would a UV filter help or hinder?

We also have two rare cast iron head stones (circa 1920's) that have only a painted inscription. On one, the (we assume) lead-based paint is incredibly weathered but you can just make out a lot of letters - it was last repainted in the 50's if that's at all helpful. On the other, there's no paint left at all (to the human eye) but we can just make out the shadow of letters in the rust pitting. However, not enough to reconstruct the inscription.

I've been given permission to try any non-permanant techniques (ie spritz with water) and there may be a small budget available. I have a good quality DSLR camera, random lighting and reflectors, Photoshop and time.

Any thoughts?
posted by ninazer0 to Technology (8 answers total) 7 users marked this as a favorite
Digital cameras are not sensitive to UV and unless you have expensive quartz lenses designed to pass UV your glass lenses will block UV anyway, some people use a UV filter to protect the front element of their lens - but that will only decrease the quality you are going to get.

If you were having reflection problems, a circular polarizer filter might help, but i doubt you are having reflection problems.

Photoshop to enhance contrast around the letting is probably your best bet.

Its possible certain color filters - or optical bandpass filters could enhance the contrast optically - but i don't have any experience with those.
posted by TheAdamist at 5:34 PM on March 26, 2019

As far as carvings go, using an off-camera flash on a cloudy day is still the best method that's accessible for most people when trying to recover information from weathered inscriptions. It sounds like you've already done a bit of this, but if you'd like more information this person has written some good instructions and listed several links for additional details on equipment and techniques. Here's a video that same person made.

Fiddling with contrast and gamma in photo editing software might eek out a bit more detail from your photos, but not much more. I've also heard of people using photogrammetry with limited success (I think there are some free apps for this you could try on your phone).

If the carvings have weathered away to almost nothing, there isn't much more you can do photographically to bring them back. Non-photographically, here's somebody using cheap, thin aluminum foil to take an impression from faded carvings.
posted by theory at 6:05 PM on March 26, 2019 [2 favorites]

I've had some luck with using Photoshop's Select Color Range to make marginal inscriptions readable.
posted by zamboni at 4:06 AM on March 27, 2019 [1 favorite]


Then photograph the rubbing
posted by Lanark at 4:49 AM on March 27, 2019 [1 favorite]

I would probably use continuous lights rather than a flash, because it'll be easier to judge when you have the angle right. If you have a source of AC power you can just use 500W halogen worklights, they're cheap and generally easy to find.

Cloudy day is a must, or do it in the morning/evening when you don't have any direct sun. You could do it at night, too, but you'll need a lot more light and reflectors.

There are two variables I'd play around with, although I suspect it'll take a lot of experimentation.

The first variable is the angle of the light relative to the face of the object. You can accentuate even very shallow carvings and other surface detail with strong sidelighting. Although at some point the shadows just run into each other and it'll be self-defeating. So maybe start around 45-50 degrees off-axis and move the light slowly further off (increasing angle from perpendicular axis) and see if that produces any detail.

The other variable is the color of the light. You can also use colored lens filters or use Photoshop, but I think you will have better luck if you actually color the light source, since then you can eyeball it—the human eye is quite good, so for a delicate task like this I'd try to get to the point where you can see legible detail, then try to photograph it, rather than taking a bunch of photos of what looks like nothing, and then hoping you can pull the detail out of the pixels in post.

I'd get some theatrical lighting gels in various colors. I've had a sample kit like this one in my bag with my hot lights for years. They're cheap. Be careful using dark gels on hot lights; they can melt. (It happens.)

Basically, to increase the contrast with a particular color, you'd want to illuminate it with a color that's opposite it on the color wheel. So if an inscription was originally in reddish ink (or it's reddish-brown from oxide), you might want to try something in the green/cyan range. Bear in mind that your light source already has some color cast to it; tungsten lights are very yellow compared to strobes, and fluorescents tend to be a bit green. Overcast sunlight is very blue.

Other oddball things I might try would be a UV light source, just on the off chance any pigments that might have been used will fluoresce. Note that this doesn't require a UV camera—you're illuminating with UV, but recording the visible-light fluorescence produced when the UV strikes a particular material. There are both "shortwave" and "longwave" UV lights; if you have an idea of what the stones were painted with, someone knowledgeable in forensics might be able to suggest one vs. the other.

I have heard of, but never tried, a forensic photographic technique that involves lightly spraying surfaces with a UV reactive dye (I suspect dilute laundry detergent would work, since it contains a lot of UV brighteners, but that's just speculation on my part) and then spraying it with something neutral, or some type of solvent... the idea being that you end up with more dye left on nonporous surfaces, where it doesn't wash off as easily. I don't know if that would be acceptable on gravestones, but maybe something to consider. You'd need to do some serious experimentation on an unimportant surface, though.

Oh, and as one final recommendation: when you are doing all of this, I would set the camera up on a tripod and not move it. Or have multiple cameras, one of which at least doesn't move at all. It's possible that by stacking images taken with different lighting or other techniques, you could recover additional detail. This is sort of an art form in itself, and I'm no expert, I've just seen it done. But it's very hard to do if the camera isn't static.
posted by Kadin2048 at 7:23 AM on March 27, 2019 [2 favorites]

As an additional note, I strongly advise NOT spraying substances on head stones or monuments -- especially any that are so old and weathered that the inscriptions have faded -- without first discussing with whoever is in charge of the cemetery. It would generally be a good practice to also get permission from a descendent, if that's possible.

This group is dedicated to promoting a set of best practices and "do no harm" methods for cleaning, restoration, and preservation of cemeteries. They are US-based, so the cleaning products they discuss may not be available in Australia, but there's a lot of very useful information on this site.
posted by theory at 9:08 AM on March 27, 2019

> https://en.wikipedia.org/wiki/Stone_rubbing#Gravestone_rubbing
Then photograph the rubbing

Please, no. Gravestone rubbing is not permitted in most historic cemeteries, as it causes more damage than one might think. Sometimes it is actually illegal per the municipality, sometimes it is prohibited by the cemetery itself, and sometimes it is permissible only by permit.
posted by desuetude at 12:13 PM on March 27, 2019 [3 favorites]

I strongly advise NOT spraying substances on head stones or monuments

Excellent advice! My question is off the back of a short course I just finished which was essentially two days of what not to do and examples of such, so rest assured I've no intention of spraying anything on anything, or of touching the monument at all if I can help it.
posted by ninazer0 at 3:58 PM on March 27, 2019

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