Shooting reflective tape with flash !??

[Hevii Guy]

Hello all,

I sometimes find myself in dark industrial environments where off-camera speedlights are necessary. Can anybody describe how one would shoot people wearing safety clothing with 3M reflective tape under such conditions? Thanks in advance!

[Manfred M]

The tape is designed to reflect light at back parallel to the light source, which in turn are assumed to "close" to where the eyes of any observer are. The closer the light sources is to the optical axis of your camera's lens, the more pronounced the effect will be. The types of light sources that would tend to be used to "activate" the effect will tend to be small directed point sources like flash lights or headlights (and unfortunately, small flash).

To me this suggests that the lights you are using need to be positioned well off the optical axes (both vertically and horizontally) as well as being emitting diffuse light (like a soft box). If I were to try this, I suspect I would almost look at what classical portraiture lighting 45 / 45 lighting (lights positioned at 45° from the camera at an angle pointing down at 45°). I have no idea as to the type of setting that you are shooting in (ceiling height, distance from walls), so large diffusers may or may not do much,as these have to be quite close to the subject to not act as hard light sources.

[Mike Buckley]

Despite all the theory, I would have a very difficult time reliably photographing reflective tape without repeated practical know-how. The best way I can think of obtaining the practical know-how is to buy the tape, stick it to some fabric and photograph it. It's not relatively expensive (though also not cheap), so that's definitely the way I would go.

[tao2]

Hello all,

I sometimes find myself in dark industrial environments where off-camera speedlights are necessary. Can anybody describe how one would shoot people wearing safety clothing with 3M reflective tape under such conditions? Thanks in advance!

Hi Jörg,

Shoot in B+W or convert tae B+W.

[Manfred M]

Hi Jörg,

Shoot in B+W or convert tae B+W.

I'm not quite sure how that would help.

You get massive specular highlights from that when you shot that material with on-camera flash (or something like a Stroboframe, that takes you a bit off-camera). The whole taped area and even some adjacent pixels are totally blown out.

The issue would be there with both B&W and colour.

[ionian]

I'm reminded of an article on Strobist, where David Hobby is talking about controlling specular highlights on glasses. He tells the story of a pro portrait shooter who kept a big box of spare frames with no glass, that he would swap with his subjects real glasses before shooting.

The lo-tech answer would be to cover the reflective tape with white gaffer tape (or something similar) before the shots. I'm presuming that if you are using off-camera flash you have control of the set-up, so there wouldn't be an issue with it being covered for a short period of time from a safety perspective.

It's a cheat but it may be the simplest solution.

[Manfred M]

The lo-tech answer would be to cover the reflective tape with white gaffer tape (or something similar) before the shots.

I don't know about the industrial health and safety laws in Switzerland, but that would definitely be illegal in Canada as you would be purposely disabling a safety device in a work environment. Large fines and jail time? Definitely not an acceptable workaround.

[ionian]

I don't know about the industrial health and safety laws in Switzerland, but that would definitely be illegal in Canada as you would be purposely disabling a safety device in a work environment. Large fines and jail time? Definitely not an acceptable workaround.

If their health and safety laws are like their banking laws, they can probably get away with working in bikinis. Might make for some interesting pictures...

...but of course that's why I noted he would need to be in control of the shoot, to find a place that represents the subject correctly but doesn't risk any scary penalties.

[Manfred M]

...but of course that's why I noted he would need to be in control of the shoot, to find a place that represents the subject correctly but doesn't risk any scary penalties.

Unfortunately, that is generally not possible when shooting in an industrial environment. Once the safety equipment has been defined for that part of the facility, it's a legal requirement 24/7.

Can the rules be relaxed; yes there is a process to do so, but it is cumbersome and requires a risk assessment and agreement of the the local Health & Safety committee (equal representation of management and workers. In a unionized work environment, union representations would be on the committee as well). So if you are trying to get a shot of the CEO beside a non-operational piece of equipment taken during off-hours, yes that could be done.

If you want to get a shot while actual work (even simulated work) is being done, forget about it. The safety inspectors would love your image because you have provided them with the evidence to lay charges and have anyone involved convicted. My 35 years as an engineering manager and plant manager in industrial environments suggests this is not an approach to be taken lightly (and yes I've sat on those committees and been involved in the technical assessments).

[Inkanyezi]

I think you first must decide how you want the reflective garments to display in the image. My idea would be something akin to the Lagerfeld campaign in France, using just enough on camera light to make it stand out, and subduing general lighting (off camera flash or ambient) so that the properties of the garments would stand out sufficiently in the picture.

So general lighting, off camera, should be set for somewhat subdued environment as well as brightening the fluorescent colour of the garments and just enough light from the camera should make the reflective tape stand out without total clipping with halos. Possibly the on camera light could be continuous, as a LED flashlight. A strobe might be just too powerful, but can be subdued by covering with something semitransparent.

[Ken MT]

If indoors could you use bounce flash. For a model, use a tame firefighter, the strips show very well, cheaper than buying tape.

[Manfred M]

Have any of the people replying ever been inside an industrial building??

Typically ceilings are no lower than around 6m / 20ft, but usually considerably higher (air handling and general lighting are all up there), so this might be found in a light industry building. 30m / 100ft ceilings are not at all unusual in heavy industry. A situation where safety vests are required implies motorized material handling equipment, like fork lifts are in use or large overhead gantry cranes are being used.

Bounce flash?? I think I can pretty well guarantee that this is not going to work except in a few limited cases near the walls. Lighting is generally based on labour code requirements with low level overall lighting (to reduce minimize energy costs and reduce eye strain, with task lighting being in place where addition light is needed. Lighting is often a combination of daylight and artificial lighting. While cool white florescent and high pressure sodium lights have lower operating costs but it is definitely the type of lighting you want to overpower with your flash.

[Hevii Guy]

It was a pleasure to have awakened to a good bunch of answers! Unfortunately, other than the suggestion of covering the tape, none seem to have provided a viable technical solution (thanks, anyway!)

Notwithstanding composition requirements, unless I'm missing something (I actually hope I am and that somebody will point it out), attempts at strategic light placement won't be effective. The problem is that tape wrapped around somebody's coveralls is not 2 dimensional as many other reflective surfaces are. Thus, the Family of Angles seems to be almost infinite from the perspective of the camera.

Cutting back on flash power is likewise ineffective since then everything else will be too dark.

I can't imagine this being "impossible" since I've seen a number of such shots where it seems to work. Surely these aren't merely examples of some crazy-super Post Production magic?

I hope that this thread continues...

[Manfred M]

It was a pleasure to have awakened to a good bunch of answers! Unfortunately, other than the suggestion of covering the tape, none seem to have provided a viable technical solution (thanks, anyway!)

Notwithstanding composition requirements, unless I'm missing something (I actually hope I am and that somebody will point it out), attempts at strategic light placement won't be effective. The problem is that tape wrapped around somebody's coveralls is not 2 dimensional as many other reflective surfaces are. Thus, the Family of Angles seems to be almost infinite from the perspective of the camera.

Cutting back on flash power is likewise ineffective since then everything else will be too dark.

I can't imagine this being "impossible" since I've seen a number of such shots where it seems to work. Surely these aren't merely examples of some crazy-super Post Production magic?

I hope that this thread continues...

Unfortunately, you have given us some very vague problem and without anything particularly useful to work with, so there is a touch of speculation going on here. We have no information on the size of the areas you are shooting, type of equipment used (types and quantities). light modifiers used, etc.

Do you have images that you've tried and can show us the light / camera positions?

That being said, I am somewhat familiar with the 3M material you are referring to. It is an embossed mylar film with tiny prismatic patterns. The back of the film is reflective (I suspect this is a thin layer of aluminum that was applied in an oxygen free environment. There is a protective layer on the outside and an adhesive on the inside. What this reflective tape does to reasonably efficiently reflect the light back in the direction it came from. An the driver of a vehicle or a person shining a flashlight will be located approximately at the same position as the light source, so the light is directed back towards that person. These devices are not 100% efficient, so there will be a relatively narrow cone of light shining back, but the drop off will be fairly rapid.

Try testing this yourself with a flashlight and a road sign (if you can find one where this is safe to do). The road signs are faced with the same kind of material. Point your flashlight at the material and you should get a face full of light. Now leave your flashlight pointing at the sign and walk away from it parallel to the sign. The reflection will dim very quickly.

This should give you a clue as to where to position your light source and your camera. The lights and camera must be positioned in such a way that minimal reflections from the reflectors are along the optical axis of the lens..


The other issue is the quality of light hitting the material. Again, we see these traffic signs in the daylight, but they don't seem particularly bright, even though the bright light of the sun is hitting them. Sunlight is diffused through the atmosphere and is scattered, so the reflective material nicely returns the diffuse light at 180° from the angle it is coming from, which is pretty well all angles. So, we know that a diffuse light sources does not reflect back in a way that causes problems in taking pictures.

Flash lights, small flash without light modifiers and head lights all share one common characteristic. They are small light sources and are highly directional. All of these will bounce light back in the direction that it came from; 180°.

This means we have a second possible solution; the use of suitably sized softboxes. They, like ambient daylight will produce light at all different angles, so the returning light will also travel pack at the incident angles, which are highly variable and will not produce the brilliant light reflections you are fighting. As long as the softboxes deliver diffuse light, you should be able to set you camera pretty well anywhere to get the shot. Any softbox I have used can be double baffled, so the light is extremely soft and non-directional.

There are some practical issues involved that may make this an unacceptable solution. Soft boxes become point sources as they get further from the subject, so depending on the scene, the power of the light source and the size of the available softboxes, this may not work. Suitably sized softboxes will not work with small flash, so studio lights would be required as they can emit an order of magnitude more light than the small flash.

Now, please tell me what is wrong with my analysis of the situation as to why these two solutions would not work. I understand the properties of light quite well, I understand how the 3M product works and of course how the photo equipment needs to be set up and works.

[rpcrowe]

I don't know about the industrial health and safety laws in Switzerland, but that would definitely be illegal in Canada as you would be purposely disabling a safety device in a work environment. Large fines and jail time? Definitely not an acceptable workaround.

Occupational Safety and Health Administration OSHA sets the standards for occupational safety in the USA. One of the "most important" OSHA regulations is that if you have a restroom which is used by both sexes (hopefully not at once) the toilet seat must be of the split variety! Thankfully the government is looking out for us!

[Manfred M]

OSHA regulations is that if you have a restroom which is used by both sexes (hopefully not at once) the toilet seat must be of the split variety!

I'd love to read the research / rationale to establish that regulation. It sounds like it probably dates back to almost a century ago.

On the other hand, I do know that once in place, regulations can be left in place just because nobody wanted to spend the time and money to clean things up. I was working on a project with the Ontario Ministry of Transportation, who are responsible for the Highway Traffic Act. She showed my one real doozy that was still on the books at the time (and I suspect it is likely still in place) where it was necessary for someone driving a car having to have someone walk some distance in front of it with a lantern to ensure the horses wouldn't get spooked.

Another one was that the The Canada Labour Code, the National Building Code of Canada and the National Fire Code of Canada had sections that conflicted with each other; but that finally got fixed with the 2005 updates.

[Hevii Guy]

Try testing this yourself with a flashlight and a road sign (if you can find one where this is safe to do). The road signs are faced with the same kind of material. Point your flashlight at the material and you should get a face full of light. Now leave your flashlight pointing at the sign and walk away from it parallel to the sign. The reflection will dim very quickly.

Thanks for your input. Unfortunately, these cases are rarely like road signs. As I had mentioned, this isn't a 2-dimensional situation. The reflective tape is attached to not only the body of Personal Protective Garments but also wrapped around the limbs.

I'm quite interested to know how I can apply diffused lighting onto a group of workers 20m or so away in a darkened area. An underground mine chamber, where the expanse of the room must be conveyed, for example.

[Manfred M]

Actually Jörg, the two materials work identically, and while I agree that the reflective tape on the miner's clothing is is three-dimensional whereas the sign is two-dimensional; your camera's sensor is 2-D and the way the reflections are viewed, means for most practical purposes they act the same way. The tape acts effectively as a reflector pointing back at the light source.

You are quite secretive about what you are doing, but fortunately I was able to find your locked down photo website (and did register) to try to understand the level of photography you are doing. The images are nice enough, but I see no evidence / knowledge of flash photography, so I would have to assume that you have access to fairly basic lighting tools only. I see no advanced post-processing (PP) work on the images either and suspect they are generally straight out of camera or have some fairly minimal PP work like cropping and straightening. I have no idea as to what equipment you are shooting with. The previous answers were directed at a photographer who would have a significantly higher skill level / knowledge than you appear to have, based on what I can see on your website. Your secretiveness has wasted everyone's time as we do try to help members who range from relative beginners to experts. Tailoring the responses to you personal level of skill and equipment involved helps everyone.

You are not photographing an industrial site - you want to photograph in a museum. There is a world of difference here.

As you are Swiss, let me assume that you are looking at photographic the salt mines at Bex? I assume these are similar to the ones found at Berchtesgaden, in Germany. Unfortunately, my visits to that mine was almost 20 years ago and I don't have any readily available images from that trip, not that they are particularly relevant as they were taken with film. In the last 9 months I have visited two mines; an abandoned nickel mine, that is part of the Science North Exhibit in Sudbury, Canada (September 2015) as well as the Sado Island Gold Mines, in Japan (August 2015). These mine / museums do not allow tripods so that limits you to hand-held photos, possibly with external flash. None of the exhibits had the dreaded reflective tape.


Abandoned nickel mine - Dynamic Earth, Sudbury Ontario, Canada



Handheld Nikon D800 shooting up towards the ceiling - with Nikkor f/2.8 24-70mm lens at 24mm, 1/6th sec at ISO 6400



Working model in mine shaft - Sado Isand Gold Mine, Japan



Handheld shot with Nikon D800 with camera mounted SB-900 Speedlight. Nikkor f/2.8 24 - 70mm lens at 58mm, f/5.6. 1/60th sec at ISO 6400. Light bounced of roof of mine shaft.


The only solution I see for you is a hand-held, high ISO image with a fast lens (f/2.8 or smaller). Throwing light for 20m from a small flash is not something that is not going to work. The areas near the light source will be quite bright and the amount of light will drop off exponentially (inverse square law). I rather doubt that the mine will let you set up light stands in their display and to spray their exhibits with anti-reflective paint ( http://www.krylon.com/products/dulling-spray/ ), so you will be shooting from a position where any other visitor is allowed to take pictures from.

You may not be able to get the shots you would like to. You need to be realistic about your equipment capabilities, your own photographic capabilities, the restrictions you will be shooting under and above all your expectations.

One other thought. Chances of someone stealing your pictures is rather minimal; take a look at the well know photographers out there. These are wide open, not locked down websites, like yours. If you are worried about theft there are other techniques that are employed that reduce the risk of that happening.

[Shadowman]

This image was a candidate for this thread Another great scene messed up by sloppy shooting! but it is a poor example of the shooting condition you are describing.


f/125, ISO 1000 f/5.0. I was doing some low light shooting and decided to try flash, had a diffuser attached to on-camera flash. I didn't notice the reflective material until I viewed the image in the LCD. If deliberately trying to shoot with this type of material (reflective tape) in the composition; I wonder if metering off the tape would give decent results, keeping ISO at a minimum, or fastest shutter speed possible?

[Inkanyezi]

This image was a candidate for this thread Another great scene messed up by sloppy shooting! but it is a poor example of the shooting condition you are describing.


f/125, ISO 1000 f/5.0. I was doing some low light shooting and decided to try flash, had a diffuser attached to on-camera flash. I didn't notice the reflective material until I viewed the image in the LCD. If deliberately trying to shoot with this type of material (reflective tape) in the composition; I wonder if metering off the tape would give decent results, keeping ISO at a minimum, or fastest shutter speed possible?

I think this might be a clue to the solution of the problem. The first thing I would try is using the ambient lighting, whatever colour it is, and adapt ISO and WB to it. To brighten the reflective tape on the garments, a small flashlight from the camera might do the trick, and it would be visible while shooting.

The problem with flash, whether on camera speedlight or studio setup, is that you will never see the effect until the picture is taken. That is the reason why studio flash has proportional modelling light.