3. Soft light
Soft light is created by a relatively large and close light source, like an umbrella or softbox. If the umbrella is say four feet in diameter, and if it is only two to four feet from the subject's face, then that umbrella will appear large to the subject. Literally in their face, so to speak. This is a good thing, because then the subject will then see a wall of light, with light coming from their left side, and from their right side, and all these different light paths will fill in the shadows made by all the other paths. This self filling of shadows makes the shadows dim and indistinct and soft (the opposite of dark and sharp-edged and harsh). This automatic fill minimizes the shadows at the shapes like the nose and cheeks and chin, which makes the light seem very soft. The light seems to wrap around the subject, from all sides. It is a smoothing effect. For example, the soft light causes no shadows to be able show the detail of the skin pores very well, not like direct contrasty light highlights it.
Conversely, diffusion domes and bounce cards are small devices, too small to be "soft". All they can do is to provide some direct frontal fill when the flash is bounced from the ceiling. Both devices do that, direct frontal fill. There is no magic, but these are valuable when we understand how to use them. The evidence is in the pictures below.
Note one huge difference here.... The pictures on this page are all with the flash off camera, NOT on the hot shoe. One disadvantage of the hot shoe flash is that it is a flat frontal light, often not the best place for the light. With the light off camera (at a slight angle), it creates shadows, for example the shading gradient across the egg below. This shadow shading "shows" the shape of the object, and looks natural, looks good. Whereas a direct flash would just show a flat white oval. However, the off camera flash can cause severe shadows "behind" the subject. One advantage of the hot shoe direct flash is that the flash position directly above the lens puts most shadows directly behind and below the subject, mostly hidden there, out of sight of the lens. The lights on this page are all off camera, specifically to show that shadow. There is a second section on the hot shoe, linked following these red pictures.
Speedlight flash in one white 45 inch umbrella, shoot-through, fabric 10 inches from the shell.
This is a soft light. Very vague dim shadows with indistinct soft edges, very nearly shadowless. The umbrella is a very large "wall of light" seen from only 10 inches away. The light is coming from all directions to the shell, from the left and from the right and from above (see picture at end below), which simply wraps around the subject to fill its own shadows, to create "soft". The idea is Large and Close. Farther away would create darker and more distinct shadows, because the umbrella appears smaller there, with less filling effect. However this ten inches is really too close, the Inverse Square Law causes the noticeable light falloff from our right to left.
A reflective umbrella at a distance roughly same as its diameter (perhaps main light fabric at four feet) is still "close" and will still be "large" and suitably soft for portraits. The standard goal for most portraits is for lights to be "close as possible", to be "large as possible", to be "soft as possible".
Direct flash, at 3 feet from shell (exactly the same flash position, the umbrella was simply removed).
This is NOT a soft light. Sharp-edged distinct dark shadows. Instead of a 45 inch umbrella, this light is a two inch flash head. No large light, no light coming from left or right or all around, no self-filling of shadows. A direct flash is often fine, sometimes ideal, but it is just not soft. Contrasty shadows are good for showing surface detail, whereas soft smoothes things over and minimizes blemishes. There are times and places for each method of course. But this case was not one, and closeups of human faces like it softer too.
Any light more distant is relatively smaller, and to the degree possible, even more harsh, less soft. The point being, the speedlight flash head is only about two inches in size, a tiny point source relative to its distance.
Notice how the light in picture 1 wraps around the left end of the egg, and does not in picture 2. And the shell too. Human faces too. This is what soft light is. Here are 100% crops of the egg from these first two pictures, soft and hard eggs. :)
Direct flash with plastic Nikon SB-800 diffusion dome (SW-10H), still pointed at shell.
The "diffused" light is slightly softer than nothing at this 3 feet, but not much. The light is simply not large enough. There will be even less effect when the flash head is farther away, the light source simply appears smaller from there. Still a sharp-edged distinct hard dark shadow.
Diffusion domes don't do much when pointed direct... still only two inches in size. This size is only 6% of the subject distance, here in this very close case. Whereas 100% size is a good goal for close work, like a four foot umbrella at four feet.
Choosing a larger dome of 4 or 5 inches size does not change much. We want more like 4 or 5 feet. One rule of thumb is that the light's size and distance should compare to the size of the area in the picture. Which obviously is not always possible, we often must settle for much less, like for groups of people. But ideally, if we are wishing, a great goal is a six foot light six feet away for a six foot tall standing full length portrait. A 45 inch umbrella works fine too, especially with fabric at four feet for a waist up half portrait.
Ceiling bounce plus plastic Nikon SB-800 diffusion dome. This flash was not moved (same shadow), just aimed up to ceiling at about 75 degrees (the upright dome position is an inch or two higher than its light before). The ceiling is large, and it compares to a large umbrella up there.
The effect of the diffusion dome or the bounce card is simply to add a direct frontal fill to aid the bounce from the ceiling. The bounce obviously wraps around the shell and the egg well, but the bounce is the fill light for the direct light here. Which is a major improvement, but in this case, the frontal fill (at 3 feet) is brighter with darker shadow than the bounce going about 4 feet up and 7 feet back down. A camera mounted flash backing off to 6 to 10 feet for proper perspective on humans would equalize them better. These are the factors you need to consider, what the dome does, the tools you work with.
However (tricky point here), the light here is off camera, so the fill is not "frontal" to us this time (there is a link below these pictures to a similar comarison for a hot shoe frontal light). This picture is not to take a picture of a shell, but is trying to show the shadow as evidence of what the dome does. The dome on a bounced camera hot shoe flash does provide a direct frontal spill, which is fill. If the flash is directly above the lens, the shadow is directly behind the subject, harder to see, but it is there (sometimes visible, maybe under outstretched arms). But the frontal fill is the effect we seek. This shadow simply shows it exists. You can see it here. This is what domes do. This fill is what we hope they achieve.
Diffusion domes do require more flash power for the bounce however.
Ceiling bounce plus Nikon SB-800 pullout white bounce card. Same bounce angle to ceiling. The card also aims at subject to add direct frontal fill and highlight (catchlight in human subject's eyes, but on the egg here). We see the same effect as with the dome, they do the same thing (some direct frontal fill). Hard to compare degree of forward fill of the two, but I imagine them about equal (opinion). But the card does not attenuate the ceiling light like the dome, so the greater power actually reaching ceiling seems to fill the direct shadow better.
A white 3x5 inch index card and a rubber band would work as well, but don't overdo the size. The "working" or effective area of this Nikon card is about 1.75 x 1.5 inches WxH. A larger card may throw a greater distance, but which will cause a darker shadow at same distance. Sometimes less is more. When using hot shoe bounce flash, I usually use this little card for people, even at group distances, believing it helps, more than the dome.
These dome or bounce card devices have no magic properties. The photons are still just regular photons. Diffusion just scatters the light, meaning much of it misses the subject now. The only property that can have any effect on the subject is direction, due to the size of the light source, as just described. The ceiling is large, and the ceiling bounce does most of the work. The dome or bounce card simply aims some direct forward spill for fill. Which is a very good thing, but we should not believe in magic photons.
Same ceiling bounce, but no dome and no bounce card (and no fill shadow and no highlight, which they would have added). This background is darkened because it curves up vertical (see bottom picture) so the bounce misses it, and there is no fill light to fill it this time.
In general (for a hot shoe speedlight), the ceiling bounce is what does the work. Bounce is very hard to beat. It is usually as soft as an umbrella, but the shadow comes from above. Umbrellas are easier to aim, and umbrellas are normally closer (giving more effective flash power). But sometimes we must take what we can get. Bounce is free and easy, just point the flash up to a white ceiling (aimed at a point on ceiling about halfway to the subject). The flash TTL exposure automation still handles it automatically (adjusts flash power level for your aperture setting). Bounce requires a lot of power however, ISO 400 and f/4 is usually a safe starting point for TTL flash.
Bounce creates very soft light, but human faces do benefit from slight frontal fill and a catchlight in the eyes. Note that a portrait will not likely have the rear background so close, normally no direct shadow behind. But noses and chins and cheeks and especially eye sockets make shadows on the front side, and these are concerns. The frontal fill is a good thing in moderation. Did I mention that the catchlight in human eyes is good too? It adds a sparkle, which seems to make the picture more alive.
Two close shoot-through umbrellas, which fill each others shadows. Two umbrellas are much larger than even one umbrella. Same light used as in first picture, with a similar second one now on left side. Of course, this fill is from the left, not from above. This try is very flat even lighting (no shadows) because the two lights are set to be equal intensity at the subject. We would normally use some degree of lighting ratio, often with the fill light set one stop weaker, to fill less perfectly, creating very soft shadows for modeling of the shapes on the subjects face.
Here is useful information about mounting hardware to put your speedlights into umbrellas (scroll down the page there). This is very easy, and umbrellas are very inexpensive, and very satisfying. Umbrellas are Good Stuff.
Make no mistake, what the domes and bounce cards do is to add the direct fill and a direct shadow from the small flash head. For a hot shoe mounted flash directly above the lens, this direct shadow is behind and below the subject, not often observable. The tiny devices are simply too small to be "soft". The ceiling bounce is large and soft, and is aided by the frontal fill. If overdone, the fill is just a flat direct flash picture, but slight fill for bounce is the goal, and is the way the results should be evaluated.
Do try this at home, to satisfy yourself. The results are easy to judge when you know what effect you are looking for. The idea is to think about what you see actually happening, to understand that the dome or bounce card simply adds direct frontal fill to aid bounce (and adds the catchlight in the eyes). This concept should be conscious in your mind at the time.
The setup picture is for the first picture above. The subject is about what the lighting does, and the shell orientation was chosen to be as difficult as possible (that dark rear projection placed in the direct shadow). The light stand was not moved or adjusted for any picture. The flash was pointed up at times, for bounce.
All of the pictures above are manual 1/250 second f/10 ISO 200 with Nikon D300, with the SB-800 flash in CLS Commander/Remote wireless TTL mode. Pretty much point&shoot. This is a 10 foot ceiling 7 feet above shell. The ten foot ceiling is rather high for f/10, but it worked with a long recycle (f/11 failed very marginally, and fussed about insufficient flash power). I usually shoot bounce at f/5.6 ISO 200 on low ceilings, and f/4 ISO 400 on high ceilings, for lower flash power and faster recycle time.
NOTE: There was some white balance adjustment done on the pictures above, because speedlights are blue at low power and red at full power, and the range here is from minimum to maximum power (3 feet direct to f/10 bounce on 10 foot ceiling). The speedlight flash is necessarily a different color at different power levels, often causing people to confuse this result as a better or worse lighting effect, assuming it is about the little attachment, without realizing it is only about the greater flash power level requirement of the little device. Before correction, the top row below (direct, and direct dome) are close range and low power and cool, and the bottom row (bounce dome, and bounce card) are bounce and high power and warm. We would be wrong to attribute the color to either the dome or the card. The color is due to high power required for the bounce.
More words:
The umbrella is "large" and the bare direct flash is tiny. Placing the light (the umbrella) close to the subject makes it appear even larger to the subject. This is the meaning of "large". A silly picture, but the red and blue lines approximate the angular "size" of the lights as seen by the subject, and indicates the multiple angles at which light is arriving at the subject. Apparent size also depends on distance, and a close light emphasizes the "large" effect. Softness is created by being large. We always want to use umbrellas and softboxes "as close as possible". "Possible" has different meanings for head/shoulder portraits, or full length shots, or group shots, as we must always keep it out of the camera view, but the idea is always "as close as possible". Close requires less flash power too. But both large and close are THE very desirable properties which create "soft". This is simply how things work.
The umbrella does require placing the light off camera of course, but which is a very good thing in itself. The light in the hot shoe (near the lens) causes a flat light coming back to the lens, everything is the same. But the subject needs a degree of sidelighting to cause shadow variations to show its curves and shape (this effect is called "modeling"). If the flash is on the hot shoe, then the best thing you can do (when possible) is to bounce the light off of the white ceiling (when possible). The reflected light from the ceiling is "off the camera", and the ceiling makes it also be a "large" soft light there. This does require more flash power, as much as ISO 400 and/or f/4 sometimes.
The little plastic diffuser domes or bounce cards for speedlights are NOT large. Their light is also not "soft". A two inch flash head six feet from the subject is just a tiny point source, regardless if you cover it with plastic or not, and the shadows from it will necessarily be dark and harsh. These domes are very marketable, because we imagine them to have magic properties - and for $50, we ought to get something. :) I am just saying, do not let your wishful thinking fool the evaluation of your results.
However, they do serve a good advantage when used properly. The way these diffusion dome and bounce card tools actually work is that they are combined with bounce by pointing the flash head towards the ceiling. The light bounced down from that large ceiling is large and therefore is quite soft, if close enough. All the diffuser domes and the white bounce card actually do is to spill a little direct light forward to the subject, providing a bit of fill (like in the eye sockets, etc). This direct forward spill from these also creates a highlight in the eyes, to create sparkle which really helps the picture. These are very good properties, and if you judge your pictures by examining those properties, it will all become much more clear what is happening.
The diffusion dome and bounce card are great tools on the hot shoe (when an umbrella is not possible), but what does most of that work is the ceiling, or a wall, or other large bounce surface. Plan on being very conscious of the ceiling and its effect. Depending on your flashes power, ISO 200 and f/5.6 may or may not work easily on ten foot ceilings and standing subjects. Don't hesitate to use ISO 400 and/or f/4 when needed to be more comfortable, regarding maximum flash power and recycle time. Ceilings in some buildings are simply too high to allow bounce to be useful, and maybe try a wall then, or maybe a panel of white reflective board of some kind. Bounce is a very major tool for flash. Bounce is the very most you can do for a hot shoe mounted flash.
If you think about this little diffusion dome, the most the diffusion can do is to scatter the light into going different directions, meaning much of our flash power entirely misses the subject then. Outdoors, this divergent light would go astray and simply be lost forever. There is no help in that, we simply must use more flash power then. The dome or card is simply too tiny to have a softening effect at any working distance. Indoors, the dome marketing says it bounces from "all the walls", but we ought to consider the inverse square law before we believe that is possible. Indoors in a small room, perhaps the stray light bounces from the near wall, and hopefully a little of that might randomly come back to hit and soften the subject, if the geometry is workable. But it is usually much more dependable to rely on the ceiling. The ceiling is usually white, usually close, usually works. Point your speedlight at the ceiling with the diffusion dome or bounce card, as that ceiling bounce is almost the entire effect (and a very desirable effect). There are larger homemade bounce cards which block all of the overhead light, and attempt to reflect 100% of the flash forward. This reflector can be slightly larger than the flash head, but when the ceiling is available, it really loses out. When we want an umbrella, just use an umbrella. When the flash must be on the hot shoe, I prefer the small regular bounce card myself, less wasted light, and it does essentially the same thing as the plastic dome (direct forward fill plus the catchlight in the eyes). The pictures above show why I usually use the pull-out white card on the Nikon SB-800 flash for hot shoe operation, otherwise umbrellas whenever possible.
Continued
Copyright © 2008 by Wayne Fulton - All rights are reserved.
