|This page has been created to summarize what I have learned while playing with diffused flash. As such, it would seem obvious that I might learn something new with every use of these techniques so I would hope to update the page and images with some frequency. Obviously, there are commercial products on the market that will assist in a similar way. Perhaps they are better; perhaps they are just more expensive. At my current stage of the game, I do not believe that any one device will be 'best' for every photo. Most of my work in this area is to learn what it is that makes some 'tricks' work when they work and fail when they fail.
Light in photography has several 'properties'. Most obvious are color balance and brightness. Also significant are direction and diffusion (or hardness). None of these properties are on/off matters but certainly subjects that allow fine adjustments. Eventually, I hope this page will get into color balance and brightness but this first effort will concentrate on direction and diffusion.
Flash direction begins with the basic 'flash on the hotshoe' which produces harsh, directional light and shadows behind and below the subject for horizontal subjects. Shooting vertically leaving the flash on the shoe moves the shadow to the side (where it usually looks awful). Brackets and off camera cords can allow the flash to remain above the lens for vertical shots but the harshness and shadow still remain. Worse, direct flash falls off as the distance increases so parts of the subject near the flash get more light than parts farther away. This uneven exposure results in an unnatural look that most people associate with flash. The rest of this essay will address ideas to lessen this problem.
| The first step in making flash look more natural is to direct the beam of light away from the subject and toward the ceiling or some other light surface that will scatter the light more evenly across the subject. Obviously this technique works best when the ceiling is painted white and not too high. It will work in, for example, a gymnasium but the amount of light needed to send up to the ceiling so enough returns to the subject is far beyond the capabilities of any consumer grade flash. Even homes with cathedral ceilings lose a lot of the light making increased ISO settings and wider apertures necessary for good results. On the other hand, the technique is easily used in a small, white bathroom so setting up a portrait studio in the tub is more likely to have too much light than too little.
Bounce flash softens and evens out the light but can produce an undesirable look with shadows under the eyes and chin caused by the light coming from above the subject. In some cases, when working close to the subject, the light can fall more on the background and too little on the subject's face. To correct this, it is desirable to cause some of the light to spill onto the subject directly while the rest makes the trip to the ceiling and back down. Fifty years ago, this was sometimes accomplished by using a flash bulb with no reflector. Light was thrown everywhere and the results could be almost free of shadows. Reflectorless flash tubes are still made for professional units but on camera, consumer units have reflectors that must be countered if we are to duplicate the effect.
|My first experiment, within 24 hours of buying my Sigma EF500 DG Super accessory flash, was to cover the flash head with a small 'bubble bag' that was used as packaging for some camera accessory. Most of us today have access to bubble bags or roll material since it seems so many products come packaged in it. The bubble material is usually colorless (avoid those that are tinted) and have many little 'lenses' that each spread part of the light in a different direction so the sum of them all is much less directional than produced by the bare flash. The bags are easily folded away and stashed in the camera case or pocket. They are light weight and can be secured in position with tape or a rubber band. Most light goes up but some is thrown forward producing a little fill and providing a 'catch light' in the eyes.|
| Probably the biggest disadvantage of the bubble bags (and other devices discussed on this page) is that it attracts unwanted attention from people who see it and recognize something is wrong. This ranges from well meaning questions about your forgetting to unpack your flash to those who roll on the floor laughing. For shooting preschool children, it is a good technique but older children will be embarrassed to admit they are related to anyone so stupid and those planning to shoot professionally might wish to consider the kind or 'word of mouth' advertising this might generate. After all, it is not important that you produce good results but only that the people who are paying the bills think you were the best money could buy. Right?
My first experience with homemade bounce accessories came during the 1970's when I saw photographers covering President Nixon attaching a white file card to upwardly pointed flashes (Vivitar 283 or similar) that directed some light forward but sent most to the ceiling. They were shooting at full manual power having set the exposure for the room using a strobe meter. Another photographer had a flash with interchangeable flash tubes including one without any reflector (bare bulb). Both of these techniques provided softer light than the commercial white plastic shields to be placed over the flash head and wasted nowhere near the output.
|Some diffusers soften the light more than others. These same diffusers waste more light. While I was happy with the bubble bag results, it softened the direct light so much that extra exposure was needed. My next effort was constructed from a clear plastic bottle. While several types were tried, I preferred unfrosted bottles with a relatively rounded shape. Frosted plastic wasted too much light. Flat shaped bottles worked well for horizontals but were hard to fit when the flash was placed in vertical orientation. This example required repositioning when switching from horizontal to vertical (shown here). It was made from a 'Wish Bone' salad dressing bottle and shows the optional white card covering the back wall directing more light forward providing better results in larger (high ceiling) rooms. It is more prone to showing a shadow behind the subject.|
|Direct flash (above left) leaves harsh shadows behind the subject and can overexpose near objects while hardly lighting more distant ones. Bounce flash (center) illuminates the entire scene more softly but can leave shadows under overhanging objects (here a lampshade but also chins and eyes in the right circumstances). Adding a diffuser to bounce will throw a little (or a lot depending on the diffuser) direct light producing a soft shadow behind the subject. In this case there is very little difference between the bottle diffuser and the plain bounce. There is a light shadow from the lamp on the wall and a little more detail in the base of the lamp which was shaded by the lampshade in the plain bounce image.
To ease comparisons on the next row, the plain bounce image is repeated below left. Below, center is an example taken with the bounce modified by a white card (of the style I saw in the 1970's). Compared to the other diffusers there is much more light directed forward to the subject producing a great deal more noticeable shadow behind. The fill is enough in this case to reduce much of the fur detail in the brown teddy bear almost erasing the shadow under his chin. On the right we return to the bubble bag which falls between the card and the clear bottle in terms of fill proportions. For this scene, my preference falls toward the bubble bag or BBQ bottle with plain bounce not far behind. Real human subjects might introduce the issue of the diffuser adding a catch light in the eyes which is simulated here better by the old camera lens on the lamp base. Teddy bears are cooperative subjects but suffer seriously from dry eyes that reflect little light compared to the real thing.
|Diffuser choices might be changed both by subject distance and ceiling height as will be shown below.|
|Cutting the end out of a plastic bottle released more light for bounce and directed less onto the subject. This reduced the potential for a shadow behind the subject. Photos taken in a mirror will give an idea of the appearance of these home made diffusers. On the left is the frosted plastic milk bottle with the end cut out. Of the group, this diffuses the light the most but also looks the worst and is useable only with toddlers and flowers. The center shows the BBQ sauce bottle used in the horizontal position (cropped vertical for this illustration) while the right image is the same BBQ bottle with bubble material inserted inside used vertically.|
|Various experiments with different materials added little to my image quality but greatly to my understanding of what I found desirable in a diffuser. Different situations made each more or less desirable but I generally preferred the bottle end left intact when using a clear bottle. The milk jug (frosted plastic) with end removed gave good results but really looked terrible, was bulky and hard to use. I found myself shopping for groceries with a mind to recycling the containers rather than consuming the product. This is not good. Overall, the attempts to improve lighting by changing types of bottles made less overall difference than expected and no one diffuser was significantly better for all photos. The important features gained from diffusion were provided by most of those tried and all were better than no diffusion at all. My main concern moved from light quality to finding something that packed easily in the camera bag and looks 'normal' enough that people being photographed did not notice that there was something strange about the flash or the person using it. This last concern will cause most people to prefer purchasing one of the commercial units which add diffusion and an appearance of professionalism important to photographers attempting to sell their images. My current answer is the clear plastic BBQ sauce bottle which can be used with or without a wad of bubble wrap stuffed inside for more or less diffusion. The optional 'stuffing' offers easily 'adjustable' output without requiring packing a second diffuser. While not fully commercial looking, it is much less attention getting than plain bubble wrap or the milk jug models which give similar results.|
|The subject of diffused flash changes a bit when shooting close ups or macro. Position of the flash relative to the subject is made harder to control by the size of the flash and the possibility of shadows from the lens itself entering the picture. The first experiment I made in this area was to construct a wooden bracket to place the flash at the front of the lens. The flash is mounted on a small ball and socket head which allows it to be tilted as desired while the bracket itself is attached to the tripod mount of the lens so the position can be rotated to any angle. The photo shows it with the bubble bag but the system can be used with any diffuser or for direct flash. This system causes the light to hit the subject from a sharp angle which does not look like the standard flash photo.|
|The bracket really causes the rig to be front heavy and not easy to handhold. A 1/4-20 bushing was added to the bracket allowing use on a tripod. This, coupled with the rotating capability of the lens tripod mount produced a very versatile rig. Another big shortcoming of this unit was that it only fits one lens and would require construction of another unit customized to other lenses. It also requires the lens have a rotating tripod mount (uncommon on shorter focal lengths).To achieve maximum strength and a smooth contour, the wood used was a small tree branch (poplar) with bark removed. A little searching turned up the shape I was seeking from candidates brought down by Hurricane Isabel. The following image was taken with this bracket.|
|The shorter focal length and reduced working distance of the Canon 50mm f/1.8 II required a different rig. Mounting the flash either on the hotshoe or a bracket caused the light to come in from the side or even behind the subject. I needed to place the light closer to the center of the lens than allowed by the height of the flash. A diffuser was made from a 1/2 gallon milk jug. In the top rear, a hole was cut to fit the flash head. Silver tape was used to reflect light back from the top and upper front areas moving as much light as possible to the lower section where it would be diffused onto the subject from a much lower angle. The photo shows the rig used without extension tubes. Adding a 12mm tube pushes the front of the lens out enough that the recessed front element of the lens is protected from flare of the flash without a lens hood. Since this rig is used at very close range, the heavier diffusion of the milky plastic still gives plenty of light to shoot at f/16. A sample from this rig follows.|
|This essay is being posted while my 'research' in the subject is ongoing. Anyone with comments or suggestions can reach me through the Yahoo list for 'Digital Rebels' . Suggestions are welcomed not only for types of diffusion to try but also ways this page could be made more clear or more useful to others desiring to try a little play with light.|