Home of Professional Cinematography since 1996

UV - Lighting

Published : 6th August 2003


I'm preparing for a black and white feature where we would like to test using UW-lights for some shots. In one shot silhouettes of Nazi-soldiers are running where we want the Nazi-symbol really to pop out. The thought is to make the symbols white and use UW-lights. Has anyone used this trick? Does the consumer UW-lights have enough output to be shown on 200ASA film?

In another shot we have prisoners in a dark train cell where UW-lightning could be cool for the ambient light to create an uneasy and unreal feeling. We will do makeup tests but thoughts about this are welcomed.

Rolf Carlbom, gaffer. Sweden.


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Rolf Carlbom wrote:

>I'm preparing for a black and white feature where we would like to test >using UW-lights for some shots.

I guess you mean UV not UW lights and not sure how it will come out in black and white but I imagine much the same as colour film - you can get 400w black gun units not sure who makes them but I did a shoot on S16mm a couple of months back and we used these units - the closer the lamp is to the writing the better the results ! I had to use 4 units to make my stuff really pop - but it's all relative to what you want.

Also try doing a search on wildfire - they used to have all sorts of UV products

Good Luck

Matthew Woolf
London/NY DOP



Please remember that UV light is extremely damaging to the eyes and to be on a set without wearing UV filter glasses is dangerous and a threat to your health.

Walter Graff
NYC



WalterNY writes :


>Please remember that UV light is extremely damaging to the eyes


The blacklight wavelengths don't carry too high a risk, although looking directly into a 400W flood is a bad idea. It makes me squirm when I see UV cannons pointing directly into the faces of bar staff from just above
head height.

Clive Mitchell
http://www.bigclive.com



>The backlight wavelengths don't carry too high a risk, although looking >directly into a 400W flood is a bad idea.

Clive your assertion is not exactly correct. Numerous studies of UV light and exposure show that all UV frequencies including near UV (UV-A 400-315 nm), the region black lights operate in (UV-B 315-280 nm), and the erythemal region (UV-C 280-100 nm). can and do cause various forms of macular degeneration.

Your cornea protects the eyes from normal daylight exposure to UV radiation with specialized cells called epithelia cells that absorb standard forms of radiation. Notice I used the word "normal" as in designed for a specific amount of radiation, as in our daily exposure to normal sunlight. An over abundance of UV radiation whether log-term of high exposure or over short-term (snow blindness for example) causes degeneration.

With snow blindness areas of the eye form small and temporary lesions in reaction to the over abundance of UV-B radiation. The medical term for the condition is Photo keratitis. If you are a skier or a welder you may know the condition as your eyes feel irritated soon after and feel like they have dust in them. That sensation is the lesions forming. The inflammation of the cornea in these spots is the bodies natural protection (as is all inflammation). After time the body rebuilds the areas where large pockets of epithelia cells were destroyed.

While the eye helps filter UV, long term exposure or in the case of motion picture work, extensive short tem exposure can and does form molecular changes in the protein structure of the lenses of the eye and what you end up beginning is the process of cataract formation. And the science shows that even the visible areas of blue light with UV fixtures can cause macular degeneration as the retina suffers photochemical damage caused by shorter blue wavelengths.

While short term exposure is normally repaired pretty well by the body, UV damage is cumulative, so while you might think a few UV shoots a year are fine, consider you are getting 100 times the exposure of UV light than you would at mid day, so five days of shooting UV is really like a year and a half of hanging out at midday.

While the film industry has not addressed the issue, every other community has. For years we used poison cookies and the like for smoke effects while other industries banned the use of these chemicals, until someone finally made the association. Many times the film industry is last to know. These companies that make these fixtures all say that any damage is always temporary. But the long term accumulative damage is well documented. All it takes is to get a pair of clear UV protecting glasses and wearing them on a set. I require such items on every shoot for all personnel.

OSHA standard 29 CFR 1910.133 requires eye protection for ANY exposure to potentially injurious light radiation such as UV light and at very low levels to boot. I strongly suggest you consider it for the long term protection of your eyesight. Even now regulations have recently been lowered in the US to include very short term, low level exposure to UV light. For instance germicidal lamps now must have UV protection or all of those people working around them must wear UV eye protection. So if a bug lamp now needs to have UV protection, what does that say about fixtures that produce hundreds of watts? Be smart!

Walter Graff
"Used to study astrophysics and knows a bit about UV radiation"
Amherst, MA


WalterNY writes :

>So if a bug lamp now needs to have UV protection, what does that say >about fixtures that produce hundreds of watts? Be smart!

If the bug lamp has UV protection, then it's not going to attract too many bugs.

I wonder if any research has been done into the eye condition of people who have worked in themed environments with a high UV level for blacklight illumination.

This makes me think of the time I went for an eye test and was sat in front of a peripheral vision testing machine. It moved a dot about on an XY axis and then flashed clusters of LEDs in random locations. I had to press a button repeatedly to indicate the number of dots that I had seen flash. Either the machine was in a bad location for ambient light or I really did fail horribly. The gist is that I wonder if people who wear dark glasses suffer damage to their peripheral vision by ingress of intense light around the sides of the lenses while the eye adjusts to the dark image seen through the lenses themselves.

Just another thought on man made visual problems.

Clive Mitchell
http://www.bigclive.com



>I wonder if people who wear dark glasses suffer damage to their >peripheral vision by ingress of intense light

Well, I always wear sunglasses outdoors, since I was a kid (Headaches from too much bright sunlight) and my peripheral vision is still better than average, as of my last check-up.

George Hupka
Director/DP, Downstream Pictures
Saskatoon, Canada



>If the bug lamp has UV protection, then it's not going to attract too many >bugs.


I was using a figure of speech there. The requirement is now for all folks who work around germicidal lamps to wear UV protection.

Walter Graff
NYC