Monday, August 11, 2008

Light modifications

This post is going to explain the various light modifications that I use in my portrait photography. This will serve to illustrate what mods I mention in posts, as well as to show how you can modify a small studio strobe.

First off, bare bones flash with skyport wireless trigger. This is the foundation, where everything builds off of. The skyport triggers the flash wirelessly, the front of the flash can accept gels (there is a 1/2 CTOrange gel in it in this photo), and the head can zoom from wide, normal, and telephoto.


Next, is a "bare bulb" emulation mod. This is just a white frosted container that scatters the light in all directions, like a real bare light bulb would do. Normally the flash is directional, but with this mod, it works like an omni-directional light, sending light off in all 360 degrees. Useful for lighting small places, hiding inside a real lamp, car interiors, etc.


Now I've attached a Dave Honl 1/8" gridspot. The flash head is zoomed out to telephoto as well. This mod throws the light in a very tight, very narrow beam. Useful for isolating the light to a single area.


This is a Lumiquest Softbox II. Normally the flash "size" is exactly the dimensions of the flash head. This gives a very hard light that is not very flattering for a front light. By increasing the light's apparent size, you get a softer look. This small softbox doesn't blow over in the wind like my umbrella does, and allows for a great feathering affect that's harder to achieve with an umbrella. I'll demonstrate the feathering affect in my next portrait post. I am in the process of building a snoot for this softbox, which will give me a soft, isolated light.


This one brings the juice. It's the 285hv cranked to full power, with a small slave flash velcroed on top. The 285hv has a GN of 120, and this slave flash a GN of 80. This gives me a GN of 144 (thanks for the math Jasphoto) brighter than the high end canon and nikon flashes. The flash only has 2 settings, high and low, but I leave it on high, and set it to slave, and it's triggered when the main flash it's on top of goes off. The same velcro that I attach the soft box to, holds my skyport slave on the side of the flash.


This is that same setup, aimed into a silver umbrella. Right now the handle is choked up on, but if I extend the umbrella all the way, this really packs a punch of soft light. Great for groups, or if the light has to be out of the frame on a wide angle shot.


Now I've attached a white nylon sheet. This is just white rip stop nylon from a fabric store, with grommets for the umbrella tines to go through. It has a slit to the middle for the umbrella shaft, and then had fray-check (a sort of fabric glue) to keep the slit from fraying. This setup is incredibly soft, and extremely powerful. With the slave flash velcroed to the 285hv, it can really pump out the light. The reason I like this better than a white shoot-through umbrella, is that this provides a 43" flat white soft light, rather than a rounded one that curves away from the subject. It makes a difference in the wrap around light.


In the future I'm planning to build a small card for the honl grid to further restrict the light to a tiny area, a snoot for the softbox, and a snoot for the white nylon'ed silver umbrella. Being able to "not light" is almost as important as being able to light. Control is the artist's tool.


  1. You guide number math is incorrect -
    to add guide numbers, I do the following:

    sqrt(120^2 + 80^2) = 144 +/-

    Remember the Inverse square law to double the 120 guide number you would need 4 (FOUR) units.

  2. Thanks for the math Jasphoto, I appreciate it. I incorporated the correction into the main post.