What Umbrellas DoWhy everyone needs an umbrella (Re: photography) |
There are more sample pictures similar to the above, as part of another section pertaining to understanding flash basics:
Flash Photography Basics - Four Fundamentals we must know
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 studio 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, about what you might expect: The Nikon spec chart in rear of speedlight manual specifies the angular coverage of each zoom setting, and an umbrella requires 2 arc tan (opposite measured radius/adjacent shaft length) degrees to fill it. The speedlight 24mm zoom setting is near 80 degrees, which is about right to fill an umbrella. Take a flash picture of the shadow of the umbrella on the wall behind it to be sure about any spill that you may have. In the same umbrella, the SB-800 at 24mm zoom meters one full f/stop less light than the 160 watt second Alienbees B400, and one stop is half power. One SB-800 at 24mm zoom ISO 200 manual full power will meter over f/11 at 4 feet from fabric of 45" reflected white umbrella, and one will meter f/5.6 at 10 feet for groups. Two umbrellas are stronger, depending on how they combine, but never over one stop more. Close portraits in CLS Remote/Commander mode are easy at f/8 with two of them (but recycle time is not fast). According to Nikon's Guide Number specificatiions, I bravely assume the SB-600 ought to be within 1/2 stop of this (at 24mm). My Smith Victor 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 than a white one, but white is much better for portraits of humans. And silver cannot be shoot-through, but it has a good reputation for furry pets which we want to be shiny.
What makes an umbrella or softbox be a soft light is its large size relative to the subject. A little 12 inch speedlight softbox simply can do very little, as compared to a 45 inch umbrella. Ideally, its size should be at least the same size as the area or field that we are photographing. A 45 inch umbrella (which measures more like 40 inches) is a very convenient size for portraits. 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. Large and Close is what makes soft light. Full length portraits or groups make close less possible, but these more distant subjects dont need as much softness anyway. An umbrella will give the same soft lighting effect as a softbox. There is no magic in the specific fabric, instead it is only the large size and close distance that creates soft light in both.
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). Softboxes are usually double baffled, to minimize any hot spot that close shoot-through umbrellas can show. 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.
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), the umbrella is tilted 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 kits are two each: umbrellas, 8 foot stands, umbrella brackets, and one carrying case):
Impact 32 inch $99 (includes flash shoes, but no case included)
Smith Victor 45 inch $113 (no flash shoes included, stands are not air-cushioned) This one was used above - I like it a lot.
Photogenic 45 inch $152 (no flash shoes included)
Photoflex 45 inch $165 (medium weight stand with larger footprint for heavier studio lights. No brackets or shoes included)
These kits seem a real bargain for what they do for us. The umbrella dimension is the rib length (or fabric dimension), measured over the curved top, so the actual straight-across diameter will be a little less, perhaps 40 inches for a "45 inch" umbrella. Do not expect it to be 45 inches. Eight foot stands are tall enough for reflected umbrellas under a ten foot ceiling. An eight foot ceiling will be a problem for full length portraits, but seated portraits will work well.
All four links here are convertible umbrellas, which can optionally be used as either reflected or shoot-through.
To use as reflected, the light stand pole is in the center, with the subject on one side, and umbrella and shaft on the other side. The light points into the umbrella, reflecting back to the subject. The bottom of the umbrella shaft points to the subject. So the umbrella fabric is necessarily more distant, at least the shaft length distance from the subject. The black cover minimizes spill out the back side which could bounce around the room.
For shoot-through operation, the black cover is removed, and the umbrella is in the center, with subject on one side, and the umbrella shaft and light stand pole on the other side. The top of the umbrella shaft points to the subject. The light points into the umbrella, and continues through it to the subject. This arrangement allows the shoot-through umbrella to be quite close to the subject (a foot or so). The main difference is this fabric-to-subject distance - both are diffused, but the shoot-through can be closer and appears larger.
Speedlights also need flash shoes added on the umbrella bracket, to fit the speedlight flash shoe foot. This shoe is really the major decision to make, since the rest all works out so easily. You can pay twice as much for a metal umbrella bracket, but these plastic ones (polycarbon?) work perfectly.
The Impact bracket includes a minimal aluminum block flash shoe (yellow at right), which I would recommend replacing with one of these two good ones below, to hold the the flash securely. I never saw ANY issue regarding the bottom clearance for the flash pins, it seemed sufficient to me, never gave trouble. My issue was that the set screw just loosens by itself, very rapidly, 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 (red knob), which made me very happy. These aluminum block shoes are available separately for $7, but the Stroboframe shoe is so much better for $3 more.
Good flash shoes
Stroboframe 300 shoe My preference
Crane shoe (with Nikon pin lock)
The plastic Nikon AS-19 stand will work here as a flash shoe too (it has the 1/4 inch thread on bottom), but its length interferes slightly with the bracket knob, and it does not feel as sturdy. In contrast, 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.
Just to understand how it works, the umbrella brackets do include brass insert adapters (like these for example), which optionally can go into the top and bottom of the bracket. The one with female thread could be used in the bottom to fit on a camera tripod, and the one with male thread goes in the top to provide the 1/4 inch thread to hold the flash shoe (the flash shoes are not always included). The assembled picture at top right shows the brass insert in the top of bracket to hold the flash shoe, but the bottom insert is not used - the bracket simply fits on the standard stand mount.
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, very satisfactory. 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 becomes 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: The pole sections of these stands have sealed bottom ends, to make a closed tube which become columns to trap air, so that a closed tube inside it will not easily 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 for ultra light-weight loads like umbrellas and speedlights, I prefer stands that are not air cushioned. I like them to be smooth operating, so they are a pleasure to use, instead of having to wrestle them down every time, trying to lower it against the air pressure. Just do always remember to always hold them before loosening them. :) They will drop instantly if you release them, but it seems very reasonable to remember this. Umbrellas and speedlights are very light-weight. The above links except the Smith Victor have air cushioned stands. Light stands are available as thin and lightweight, or thick and heavy for loads. The load is not so much the vertical weight. Instead it is the offcenter weight, like an umbrella or softbox (and especially a boom arm), with most of the weight out on a lever arm. This offcenter load tries to lean the stand pole sideways, and can easily tip it over. The footprint (the diameter where the legs touch the floor) also becomes important to prevent tipping, larger diameter is more stable. Pay attention to place one foot directly under the offcenter load (the umbrella or softbox), to resist this tip. However, umbrellas and speedlights are very lightweight, with no particular concerns, while large softboxes and studio lights are much heavier and a quite different ballgame. Boom arms are in an entirely different class, and even a speedlight on a short arm is formidable for a lightweight stand. Three of the kits above have lightweight stands, which are very suitable for umbrellas, but dangerous for large softboxes. |
Removable black cover: On "convertible" umbrellas, the black cover comes off quite easily for shoot-through use. The black cover has no effect on the reflected properties, it simply prevents stray spill light out the back of the umbrella. Or you can remove it to diffuse the light going through the white fabric for shoot-through use. 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 be a large and well-diffused light source. This 60 inch Photogenic Eclipse version (about 48 inches straight across) has the white cover (more of a satin finish - shown in the Stroboframe background) which is 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 then the umbrella fabric itself covers and better 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. A 60 inch is good for larger work, full body shots and groups.
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.