How to photograph exhibition w UV-light source

[Patrik Roseen]

Hello, I am asked to photograph an art exhibition this evening where the objects are exposed to both halogen lamps and special UV light bulbs. The UV light makes the objects glow and really makes them stand out from the background.

My intention is to photograph with Ektachrome VS100. However, I am not sure the UV-glow will pass my lens nor stick on the film.

I will also use a SA f8/75mm with centerfilter which might makes things more tricky. Some people talk about color shifts using center filters.

I will use the existing ambient light in the room which will be very dark and expose for the light on the art objects. For correct color on the film I usually add a short flash.

What are your recommendations regarding lightmeter reading (spot meter), will it pick up the UV-light?
Should I turn off the UV-light and only use the halogen spots?

All experience welcome.

[cowanw]

I would have thought that the reflected light that you are useing to expose the film would be a normal visible wavelength. Different than the ambient invisible UV light.
I would suspect a reflected light meter measurement would so.
Thought I would stick my neck out with an opinion until the experts( someone who has done it ) answers.
Regards
Bill

[Wilbur Wong]

I'm no expert, however I believe that the "self luminance glow" caused by the excitation of the near uv lamps are of wave lengths that are all within the human visual range and therefore would record on film similar to the human response.

Color films are not specifically designed to record below 400 nanometer. A quick glance at published Kodak spectral responses seem to indicate a slightly extended range with negative color film over transparency film.

I think that any additional lighting would reduce the balance of how much glow would be apparent in the recorded image. If the visible wave length halogens were turned off, all the viewer would see should be the portions of the paintings which have fluorescent pigmented paints.

Whether the photograph emulates the effect of a "black painting" may well require test and experimentation. Possibly a back lit duratrans may be the most effective.

[Patrik Roseen]

Bill and Wilbur, thanks for your respons.

I think/hope you are correct. The UV lamps probably do not produce true UV spectrum but more limited to frequencies close to and within the spectrum of what the film will record. (These are of the type to be used as disco-light in the home)

Whether or not to add additional light (flash) is an interesting question. My strategy is to do it both ways. Actually turning off the halogen lights as Wilbur propose is something I will also try.

I am still most concerned with how my lightmeter will react to this type of light. Will the reading be too high or too low? I will bracket to be sure the result will be acceptable.

Just for clarification: The SA 75mm will be used to photograph the exhibition setup/room. For the objects themselves I will use a Symmar-S 180mm.

I am off to the exhibition now...many thanks, Patrik

[Helen Bach]

Patrick,

I have done a very similar job: an art installation that was a mixture of images projected by a normal 35 mm slide projector (ie tungsten balanced) and UV fluorescence. As already mentioned, the fact that the fluorescence is visible means that it will record on film just like 'normal' light. I used Ektachrome 64T which gave a neutral balance with the projected images and a deep purple-blue for the fluorescence. I metered by doing a visual comparison/estimation between the brightness of the fluorescence and that of the projected image, and metered (reflective) in the comparatively neutral, full-spectrum parts of the projected image, with the meter cell shielded from the UV lamps. Though I bracketed, it turned out to be unnecessary.

Best,
Helen

[Ole Tjugen]

There is a certain risk that the UV illumination will register on the film as a heavy blue cast - at least that's what happened to me many years ago when I shot some fluorescing minerals. Next attempt was with a UV-blocking filter (pale yellow, much stronger than an ordinary UV filter), and that turned out very nicely.

[Patrik Roseen]

Helen and Ole, always nice to hear about others experience.

It turned out that the main problem might not be the UV light, but instead the very huge range in lighting of the objects. Most objects had very bright areas from lighting and alot of shadows including detail but the range was really too wide for the chrome film I used.
I tried adding flash in the hope that it would even out the light, bouncing it into the ceiling or nearby walls. However the exhibition room was very large and the ceiling some 12 meters up (like an arch).

So I now keep my fingers crossed. I shot a few rolls of MF 120-film using my Mamiya C330-system. I will hand them in today to my local lab. After reviewing them I will hand in the LF sheets (4x5") and possibly ask for pull or push depending on the outcome of the 120-film. With the difficult lighting I did not even consider the SA 75mm, but only used the Symmar-S 180mm.

During the shooting an evil thought came to mind - how about getting a digital?...Naah!!

[Wilbur Wong]

how about getting a digital?...Naah!!

Naaaaaaaaaaaaah, you'd be no better off. A cmos sensor is about on par with color transparency film. You would be better off photographing with color negative film due it's wider latitude.

One thing digital might well do for you in this situation however would be the instant feedback of basic exposure information. The monitor itself offers some help, the usage of the "histogram" is probably the most useful in a difficult lighting situation.

[Robert Hughes]

Try both. A couple years ago I shot both 35mm negative motion picture and Betacam video in a convention center full of mercury lighting; film turned out purple and video was blue. We preferred the video for that project.

[CG]

I guess I'm chiming in too late, but for others contemplating similar mixed light situations, wherever possible, shoot a test set of shots under the problematic lighting. Take complete notes on everything that might be relevant. Try any corrections you might need as separate exposures. Put marked cards in the scene that key your exposure to the notes and to the corrections and settings i.e. one set with no filters with a card saying "no filter"; a set with 85A filtration with a card saying "85A", etc, etc. That way if one correction works better you won't be unsure which attempt was the good one etc. Its amazing how fast I forget what I did.

Treat it as scientifically as you can, so your real shoot is no longer guesswork. If you have the time, shoot the tests as early as possible so you have time for a second set of tests prior to the "real" shoot. Your first set of tests may aim you at a new chance to solve the lighting problem.

Pretty much the same advise pretains to any technical and maybe aesthetic conundrum you have time to preplan. I hate going to do work that matters without a solid plan.

Your nerves will thank you.

Best,

C