I have a question that is probably easy to answer.
What is the main difference between using a reflective - not shoot through- umbrella and a soft box?
I know what each one does but is there a difference on when and how to use them? I know a softbox will eliminate most of a shadow behind the subject in a studio and it seems that the reflective umbrella that I use does the same thing. So is a rule of thumb of using either? Or is one better than the other?
Thanks in advance for the comments.
In general a softbox will give you a gentler light than a reflective umbrella. The biggest difference, and advantage, of a softbox is the control you get over the light. Say you want your main light at a 90degree angle from the camera, for a profile portrait. With a softbox, no problem. With an umbrella, the light will be spilling all over your background, bouncing all over the place.
If you want to do any kind of table top work, forget about it with an umbrella. No control of the light, and softboxes give you much more pleasing reflections.
Depnding on what kind of reflective umbrella you use will give you harsher or softer specular highlights in the subject. A white reflective umbrella will give you softer ones while a metalic reflective (silver or gold) will give you harsher ones where a shootthrough or softbox will give you an overall softness and flatter image.
Light quality also depends on the distance from the subject as to how soft or harsh the lighting is. If the softbox is close in you will have softer light then if it is further away. Even a softbox will create shadows if it is far enough from the subject.
Here is an example of an image taken using a gold reflective umbrella as the main light on the left and a white shoot through 2 stops down on the right for a fill. You can see that there is a specular highlight on the shoulder and that the face is able to go into shadow on the right side which is softened by the fill light.
In the next image, shot with softboxes for main and fill at about the same exposure for each you see that there is no speculars on the body and the lighting is very flat. This is the effect of using large softboxes.
In the 2 pictures here you can see the difference here between reflective metallic umbrella and all softbox lighting. You can mix them and control the brilliance and size of the specular highlights and overall scene contrast.
How much light is lost when using these modifiers? Meaning, will a softbox suck up more light the a reflective umbrella forcing you to use a brighter light to begin with?
Scott, yes you loose quite a bit of light in a softbox. Typically you will loose about 2 stops. It depends on how many layers of diffusion material there is in the light path and the internal reflector material. Some of my softboxes have white on the inside, some have silver, needless to say the silver is more efficient. Some softboxes do not have an internal baffle so you may use less light with them.
