In the last post on off camera lighting, I basically wanted you to get out and do something with your flash off the camera. Additionally, I covered something lightly about soft and hard light. Now, we will be talking about soft and hard light modifiers that you can use. This post will be beneficial to people who are also using studio flashes, too.
The first is the easiest: no modifier at all. Just point your flash at your subject. This tends to be fairly hard and if there are any shadows, they tend to be fairly well defined. Most photographers would typically say “Don’t do this!” but if it does what you need it to do, then do it. The second is using the flash as a bounce source. This means pointing the flash up at a ceiling or wall, and letting the light bounce from there to your subject. This will soften the light, and make the shadows less defined – but often will still be there. The next is using a white card – you do this by either using a 3×5 card on Velcro or use a rubber band and hold the card next to the flash. Most of the light hitting the card gets sent forward (about 20%) and the rest hits the ceiling like a normal bounce. This softens the shadows even more. I also need to mention that most flashes today have a wide angle difuser included as a pull out on the lens of the flash. It works by spreading the light wider than the flash normally would project the light.
There is another type of difuser that needs to be mentioned here, but it isn’t really a difuser. It is called a cookie. The cookie goes between the flash and the subject, and is intended to put a mottled pattern or special shadow pattern shadow on the intended target. This is frequently done for backgrounds, and in some cases, to create a “window” like shadow pattern to fake shooting next to a window.
The next diffuser will soften the light even more by spattering the light everywhere. You do this by bouncing the light in an umbrella to your subject. Even though this costs some money, it still is fairly cheap. An umbrella will cost $20-30 and an umbrella holder will cost another $20. When you set this up, the flash head should point to the center of the umbrella, and when you move it, the umbrella and flash head move together. If the flash head is bent in an odd shape or points to the outer edge, the umbrella is mounted incorrectly. Also remember to mount the umbrella at the end of the shaft so that the light hits the umbrella fully and gives the most coverage of light. There are two types of umbrellas: shoot through and reflected. The reflected umbrella will have a gold or silver reflective material on the inside of the umbrella. The light from this type of umbrella is stronger and harsher than the other type. I would discourage this type of umbrella unless you are shooting outside and need to overpower the sun. The other type, the shoot through umbrella is a white shear material that sometimes has an outer cover to convert the umbrella into a reflecting umbrella. The shoot through umbrella is the type of umbrella you want to purchase, and it will be the most flexible for the money. Something to keep in mind when buying an umbrella is that the larger the umbrella, the softer the light (and higher the light loss). The smaller, the more directional and harder the light.
Depending on the flash you purchased, there is a possibility that you have a diffusion dome included. The dome works by scattering light projected from the flash head like a bare bulb. You attach one by pushing it on the head of the flash. They are usually either a clear material or translucent white. Some are round and look like a bulb. Others are rectangular and directional. They all work the same by taking the light and scattering it – making the shadows softer. When you use one, you will find that you get better images with higher ISOs and longer shutter speeds. Depending on the type, you will either point it directly at the subject or 90 degrees from the subject. They range in price from being included with your flash to $80, depending on the manufacturer.
Yet another type of diffuser is the flash reflectors and flash soft boxes. They work by bouncing light forward into a larger size light. This softens the light by making a larger light source, much the way an umbrella does. The advantage is the the reflectors are more controllable and don’t lose the light like an umbrella because the bounce all the light to your subject. These are the light vinyl type modifiers that attach via velcro. They may have a front diffuser making them a softbox. The bad side is that they rarely provide enough light at lower ISOs. Most are sold as part of a system of configurable flash modifiers, but are also sold individually. An example is the Promax system by Lumiquest. Another is Honl. There are a few more out there, too.
Getting to pricier diffusers, there are pro grade small soft boxes. These are soft boxes that are normally used by studio lighting flashes, but only the smaller ones. The bigger soft boxes (more than 24 inches by 24 inches) eat up so much light from the flash that they aren’t practical for a camera flash. But, the smaller soft boxes can be used. They work much the same way as a reflector type modifier. These will require the purchase of a special bracket and speedring to attach the soft box to your flash. You will also want a solid light stand, too, to hold it. You may need sandbags to stabilize your stand.
Finally, there are the parabolic umbrellas. They are a special type of umbrella that focuses the light into a solid beam of light with the minimal spread or scatter unlike a traditional umbrella that throws light everywhere. Key to using one is knowing the proper distance to mount the umbrella. They also come as shoot through and reflective umbrellas. Frequently, they will have other attachments like a diffusion fabric and spill kill fabric attachments. I am mixed about using parabolic umbrellas in this way because most of these parabolic umbrellas are really huge in size. As with other softer light sources, they don’t work well at lower ISOs. You will also need a solid light stand and sand bags to stabilize the stand.
This should give you a good idea of the different light modifier attachments, and what they do. We will continue with the next post by giving some examples of common lighting setups using a few of these modifiers.
Edit: A comment was made that many people talk about beauty dishes and where do they fit into this. They fit in the group of reflectors and similar items that make the light source larger. A beauty dish is hot (brightest) in the center and then has a fairly quick fall off. Many people use them with a grid on them so that the fall off is even sharper. I frequently use them with a diffusion sock of some kind, and that softens the fall off a little bit (but nothing like a softbox).