What Umbrellas DoWhy everyone needs an umbrella (Re: photography) |
 dsc_2264.jpg 61.69 KB One direct flash at 28 inches (a random distance, seemed about right). Harsh - the usual sharp dark shadows. Some reflections on the eggs. The contrasty light shows the detail of the imperfections of the egg shell surface (this example is like human skin imperfections and wrinkles). Note that a speedlight flash head is a very SMALL diameter light source. So this is the problem.
Click an image to see a larger image(You can page through this material there too, to compare images better- recommended) |
 dsc_2266.jpg 55.10 KB One 40x32 inch double diffused softbox, fabric at 18 inches. The shadows are soft and vague. The large light source wraps light around the eggs and under the dish. The way it does that is because the 40 inch softbox (or umbrella) is 18 inches from the 7 inch dish (big and close), so light comes to the egg from the left and from the right, and from every which way, which fills its own shadow. This is how large light sources work, by being close in order to become relatively large. And large is what makes soft. The softness smooths skin, which is good for portraits. There are reflections of the eggs on the dish, but notice the soft light also lightens the dark canyon between the eggs. |
 dsc_2268.jpg 55.74 KB One 45 inch shoot-through umbrella, fabric at 18 inches. Essentially the same as the softbox (but catchlight reflections in human eyes will look different). The egg shell texture is minimized (no shadows to show it), and especially notice how the light wraps around the dark end of the eggs (more than in 1 because this is large, and more than in 4 and 5 because this is close). Imagine this contour was a nose or chin or cheek on a face. This "wrap around" is what soft light is, and large and close make it happen. And this is just one light. Two umbrellas can essentailly eliminate all shadows. The second fill umbrella near the lens axis really helps minimize wrinkles. |
 dsc_2270.jpg 54.83 KB One 45 inch reflected umbrella, fabric at 40 inches (a distance not exceeding the umbrella diameter). Almost as good, and 18 inches is not always practical. The greater distance fills less well than if it were closer, the shadows are slightly darker, but the difference is subtle. The umbrella shaft does prevent it being as close as shoot-through can be, but reflected is a wider light for larger subjects. As close as possible always applies, and the umbrella "diameter" is a typical close distance for portraits - the sitting subject typically can reach out and touch the light stand pole of the main light (not the fill however, it has to be more back with the camera to be out the way of the lens). |
dsc_2272.jpg 54.05 KB One 45 inch reflected umbrella, fabric at ten feet. Shadows darker yet, not bad, still better than a direct light, but fading fast. The light source is becoming small at ten feet, and this hurts softness. But groups do require a greater distance, for the wider width of the light beam to cover them. However closer is always better when it is possible (closer to be a relatively larger light source). Do not place the umbrellas at ten feet for a head and shoulders portrait. Should be as close as possible. |
 dsc_2274.jpg 53.54 KB One speedlight directly bounced on ten foot ceiling. Flash was pointing up about six feet distant from the eggs. The light is even more flat and even, has much appeal, but it is coming from overhead. Which is sometimes appropriate, but maybe not for portraits. The ceiling is more than 7 feet above the eggs, but the ceiling is larger than the umbrella to compensate, and a large light is what works. Bounce flash is an extremely powerful general purpose tool, however umbrellas are easier to aim than ceilings. |
About Umbrellas
It really does not much matter to the light quality if it is shoot-through or reflected, or softbox or umbrella (the amount of stray spill light scattered in the room certainly does vary however). What matters is how large it is (to create all the different angles that the light is coming from), which is often about how close it is, since close also makes it be large.
Play with this yourself, to see it for yourself, to become a believer. Nothing is ever as dramatic as seeing our own result. An umbrella is an inexpensive tool that makes a huge difference. How to use umbrellas is: large and close.
The flash used here was a Nikon SB-800 speedlight, except frame 2 with softbox was an Alienbees B400 light. The first four frames adjusted power level to f/11. Frame 5 was f/5, and frame 6 bounce was f/7, both at full power ISO 200.
Idle chatter, what you might expect: In the same umbrella, the SB-800 at 24mm zoom meters one full f/stop less light than the AB B400, and one stop is half power. One SB-800 at 24mm ISO 200 manual full power will meter over f/11 at 4 feet from fabric of 45" reflected umbrella, and near f/5.6 at 10 feet. Close portraits in CLS Remote/Commander mode are easy at f/8 with two of them. According to Guide Number specificatiions, I bravely assume the SB-600 ought to be within 1/2 stop of this (at 24mm). My SV umbrella is about one stop stronger reflected than shoot-through (at same distance from fabric, but shoot-through is typically used closer). Using the five SB-800 batteries will improve recycle time to under 3 seconds. A silver umbrella may be 1/2 stop brighter, but white is much better for portraits of humans. And silver is not shoot-through, but it has a good reputation for furry pets which we want to be shiny.
What makes an umbrella or softbox be soft is its large size relative to the subject. Ideally, its size should be at least the same size as the area or field that we are photographing, for example maybe 32 inches for typical half portraits from waist up. And ideally, it should not be farther away than about that same distance too, to remain "that large", as large as the subject. Which is just a rule of thumb, but it seems a good one for both umbrellas and softboxes, when it is possible. Full length portraits or groups make this less possible, but these more distant subjects dont need as much softness anyway.
The big difference is that softboxes are better contained, with all the light confined to the forward direction, whereas umbrellas (especially shoot-through) scatter much light all over the room. Reflections can be an issue in a small green room, but if the umbrella is rather close to the subject, then normally that overall stray path to the walls and back is much longer, and the inverse square law helps (but 3x longer path length is "only" down 3 stops). Another difference is the softboxes have reflective walls inside, and the entire box is the lights reflector, and with a 180 degree bare-bulb light source at the back, so that the light bounces around every possible which way inside to come out the front at different angles, to fill and be soft. But speedlights are constructed differently anyway, see the picture at page bottom. My opinion is that the "larger is better" theory suggests the tiny speedlight softboxes would be better replaced with a full size umbrella. An umbrella generally gives the same soft lighting effect as a softbox, the size and distance are the main factors.
And speedlights do work great in umbrellas, with an umbrella bracket like shown. There are several umbrella brackets that are all the same import product (if they look alike), relabeled with several different brand names. The umbrella bracket fits on any standard 5/8 or 3/8 inch light stand stud, or it also includes an adapter to fit a 1/4 or 3/8 inch thread, like a camera tripod. Note this bracket has a slightly tilted hole for the umbrella shaft, and when inserted from the correct side (as shown), it tilts the umbrella up even with the flashhead. The picture on some of the packages show the bracket upside down, but it must be as shown at right (umbrella on top) to position the umbrella.
There are umbrella kits available (these are two umbrellas, stands, brackets, carrying case):
Impact 32 inch (no case included)
Smith Victor 45 inch This one was used above, I like it (also see Adorama)
Photoflex 45 inch (no bracket included)
These kits range from $100 to $165 USD, which seems a real bargain for what they do for us. All four links here are convertible umbrellas, which can be used as either reflected or shoot-through. The dimension is the rib length, measured over the curved top, so the actual straight-across diameter will be a little less, perhaps 40 inches. Eight foot stands are tall enough for umbrellas under a ten foot ceiling. An eight foot ceiling will be a problem for full length portraits, but seated portraits will work.
Speedlights also need flash shoes added on the umbrella bracket. Brass insert adapters (like these for example) are included with the umbrella bracket, for the top of the bracket to provide a 1/4 inch tripod thread for the flash shoe (shoe usually not included).
The Impact bracket includes a minimal aluminum block flash shoe (at right), but I would recommend replacing it with one of these two good ones below, to hold the the flash securely. The set screw just loosens by itself, and my SB-800 fell out onto the floor twice (which seems a big deal to me). Then I ground a notch in the side of the flash foot to let the screw go into that notch, which seemed to work as a safety guard, but I finally just replaced the shoe with the Stroboframe shoe shown, which made me very happy.
The plastic Nikon AS-19 stand will work here as a shoe too, but its length interferes a little with the bracket knob, and it does not feel as sturdy. Studio monolights (like Alienbees) just fit directly on the light stand, and have their own means, and do not need the bracket or the shoes.
Crane shoe for Nikon flashes
One overhead reflected umbrella was used to take the yellow picture. There are traces of the shadow, the umbrella could have been closer, but still, umbrellas are magic. And makes it be easy. We know that a direct flash will give a harsh picture of work like this, and the point is that an umbrella makes it be absolutely trivial. A large and close light source fills its own shadows.
The Stroboframe shoe is shown again at right. A light clamping holds like a vise, very securely. Shown here with a standard 5/8 inch adapter for use without an umbrella bracket (like for background, or on a hair light boom). The SB-800 in its SU-4 mode is an optically triggered slave, and it works great with studio lights then.
Outdoors, be prepared, the wind will blow over your umbrella and light stand (with your light on it). The umbrella is a big sail, and it takes off very easily. The best plan is a human helper to always stand with it to hold it and never let their attention lapse. Or you can add heavy weights to the base (sandbags, water containers, etc), or even stake the stand down to the ground. But be prepared, this will happen.
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Air cushioned stands: These stand pole sections have sealed bottom ends, which become columns to trap air, so that a tube will not fall by itself when the clamp is released. These are great for heavy loads for which assistance may be helpful. I may be the only one with this quirk, but I prefer stands that are not air cushioned for ultra light-weight loads like umbrellas. I like them to be smooth operating, so they are a pleasure to use. I do not have to wrestle them down every time. Just do remember to always hold them before loosening them. :) They will drop if you release them, but it seems very reasonable to remember that, and they are so light-weight that they are easy to catch. The above links except the Smith Victor have air cushioned stands. |
Removeable black cover: On "convertible" umbrellas, the black cover comes off quite easily for shoot-through. Not in focus in the picture above, but the black cover has a little metal cap at the end of each rib to hold it on, which simply slides off of each rib. Also a screw cap on the center shaft, and then the black cover just falls off. Goes back on just as easily, a few seconds. Shoot-through means that the flash shines through the white fabric onto the subject, to diffuse the light well. The Photogenic Eclipse version has the white cover (more of a satin finish - shown in the Stroboframe background) sewn hanging from the underside of the ribs, instead of laying on the top side like conventional umbrellas (last picture above shows Eclipse top view with black cover folded back). So the umbrella fabric itself covers and hides the ribs from the catchlights in the eyes, however it only helps for reflected use. The metal ribs still block the shoot-through light and are visible, so there is no difference then. |
My opinion is that a speedlight and a bare bulb studio light are just not the same thing inside a softbox. One is like a concentrated (focused) flashlight beam on the center of the front panel, and one is an ultra wide light source (greater than 180 degrees) illuminating all of the reflective walls of the softbox (using it the way it was designed to work). The frosted bulb here is the modeling light, and the flash tube is the clear circle surrounding it.
But an umbrella works great on the speedlight, and does essentially the same thing. The 24mm zoom setting (provides about 80x60 degrees beam field coverage) should fill any size umbrella. Larger umbrellas have longer shafts to make this be true, so the included angle remains about the same 80 degrees (2 arc tan (opposite radius / adjacent shaft length)), so the same light angle fills either size. A larger umbrella in the same location casts a softer and wider beam angle. Or moving it back also casts a wider beam, but is smaller and less soft. Either way does require more power to distribute the light over a larger area and still have the same intensity. The 45 inch size is very convenient to use, and covers most situations.
One close reflected umbrella was used to take this picture (sort of between camera and subject, pointing down). The lack of deep dense shadows down in those deep channels beside the speedlight ought to make the point. Umbrellas are pretty close to magic.