Interior helmet markings.

[JAMES.M]

Is there any known light sources, other than white and UV light, that can be used to “bring out” lettering on the inside (on metal, not leather) of a helmet. I have a helmet that has the owners name and unit, but it is faded and illegible to the naked eye. Are there any tricks out there that someone is willing to share?

Cheers,
James

[Edelweiss]

Interesting question. I saw a TV documentary many months back, showing a very efficient process the police is using. I don't remember precisely what it was, but I wonder if it's the kind of method accessible to anybody...
No cops among us ?

[John Hodgin]

Hi James,

UV photography is probably the answer, however UV photography is very challenging. First you need a UV filter, not the clear UV filters used to filter out some or all UV light and to protect lenses, but a filter that only admitts UV light. It is opaque to human vision, i.e. it looks solid black. The one I used was $200. Then you need a strong UV light source. I photographed flowers with UV light for a client in the 1980s. The flower's pedals looked solid yellow to the human eye. In the UV photos a complex zig-zag pattern was visible. Bees and butterflies can see UV light and thus see this pattern. They are attracted to the flowers because of the pattern that we don't even know is there. The photography had to be done a darkroom with no light other than the UV source. Exposure time was 45 minutes! Using flash and new technology, perhaps it's not as difficult today.

[JAMES.M]

Hi John,

Without purchasing the above mentioned light source, where would be the best place to get something like this done? There are lots of photographers in the area, but is there any one thing to look for or ask when enquiring about these services? Thanks for the info! I’ll see what I can come up with. If the results are favourable, I’ll let you know the results.

Cheers,
James

[John Hodgin]

Hi James,

IMO, your average commercial photographer will know zilch about UV photography. Chris is "right on" that a police photographer, or someone that investigates crime scenes, is the way to go. Or, perhaps some hospitals are set up for this also, I believe UV photography has been used to study some skin disorders.

Good luck and let us know how you fare.
John

[Rich Moran]

High intensity UV is a problem to work with if you or the person doing the work attempts to do this unprepared. High intensity UV work requires the person doing the work to wear specialty glasses that prevent eye damage, as well as protective clothing to prevent problems from UV exposure to the skin. High intensity UV is a source of skin cancer.

I have used this process in corrosion control inspections, as many inhibitors will glow whitish purple. The UV use is to check for holidays where spraying of equipment or structure was performed. Expect to pay in the neighboorhood of 500.00 US$ for the lamp and the transformer that comes with it, should you decide to do this on your own.

It is not impossible to do, but if you cannot find anyone in your area that can provide you with a source for the light, you might check with companies whop sell the devices of what their customer profile is. That way, you might find one to "rent" for a short bit at the owners site. Of course, the owner would be the one to operate the lamp. If you are to be in the room with them for the testing short interval exposure might not be an issue.

Since the lamp seems to work the opposite of a regular light bulb, IE, your working in the dark, flip the switch on, and it takes about 3 to 5 minutes to get the lamp to light up, the temptation to look at the bulb for some is irresistable, and the next thing you know is at some point you have problems with your eyes. Cataracts!!! Not the one you drive either (cadillac).

Anyway, good luck in your quest and don't damage the eyes, it ain't worth it.

Rich Moran

[Jean-Loup]

I saw the police using some special light ones. I dont think it was UV... The bulbe sent out very powerfull yellow light, and so as not to get eye damage, you had to wear yellow glasses; and with these, every thing became dark, exept certain things that might be interesting on the crime scene. Needless to say, I still dont understand why just the interesting things would glow under this light; and as a matter of fact, they didnt find anything that time!
JL

[John Hodgin]

Excellent point about protecting one's eyes Rich. I should have mentioned this in my initial post. I neglected this because most all the simple "blacklights" so many collectors use carry the same potential to cause eye damage; I assumed this danger was something most all of us are familiar with. Never look at any "blacklight" bulb either. In addition, most simple blacklights provide enough UV to photograph with. This is what I used, avoiding buying the expensive lamp you mentioned.

For my UV photography, I simply mounted the blacklight on a small stand in the darkroom and aimed it at the subject. Next, mounted the camera on a tripod and did the same, then composed and focused. Then I mounted the UV filter on the lens, turned on the UV lamp (blacklight), turned off the the darkroom "white" light, and opened the camera's shutter on bulb. All this without looking at the UV light, then left darkroom and went to lunch. After lunch, I re-entered the darkroom (double doored, no white light admitted) and closed the shutter. I repeated this every day at lunch for a week using different F stops on the lens; several of the exposures were acceptable. When using long exposures the camera and subject must be in an area of no vibrations or the photos will be blurred. If you don't have access to a darkroom, covering the windows of a room, or using a basement will do. Perform the photography at night, and turn off all lights when you exit and enter the room, and you reduce the problem of light corrupting the photo.

Regards,
John