Lighting Q and A, 09-05-08

Last week, I asked you to submit any questions you might have about lighting, and promised to do my best to answer them. I am now sitting on a truckload of questions (some of which are quite good) and it is time to start chipping away at the pile.

This week, we'll visit white balance, lighting groups more evenly and how to turn down the volume on an "all-or-nothing" manual flash.


White Balance

David, from Denver, CO (USA) asks:

"What is your default white-balance setting?


David, that depends on how I am going to be lighting my photo. The vast majority of the time I shoot on daylight. I never use the "flash" setting, and here's why.

It is designed to warm up the whole frame, to compensate for the fact that flash is usually a little bluer than daylight. But for me, that's too blunt of an adjustment -- why warm the whole scene up just because the flash is too blue?

The most obvious situation to illustrate this is flashing someone outside on a nice, sunny day. That "flash" setting will fix your strobe's light, but it will also take some blue out of your sky. Not good.

Much better to shoot on daylight and fix the flash's problems at the flash itself with a slight warming gel. This way, your strobe light can be made to look neutral -- or warmer than neutral. I really like a 1/4 CTO gel on whichever flash is going to be my key light. It goes just a tad past neutral, which looks nice on most peoples' skin.

Of course, sometimes I am trying to balance with tungsten or fluorescent light. In that case I will balance the camera to incandescent or FL and then place a CTO gel or a window green gel on my flash to match it to my new WB setting. (See here for more.)



Also, you can purposely shoot in a daylight environment on the tungsten setting to create a color shift in your photo (examples here and here) but my guess is that you were talking about the daylight vs flash settings as described above.


Even Lighting for Groups


Rebecca, from Australia, asks:

"How do you modify the off-camera lighting techniques when shooting groups of people - families, for example. How do you ensure that the exposure across the group remains consistant?"


Rebecca, there are a few tricks that you can use in this situation. And they all boil down to distance and/or direction.



As we learned in L102 - 1.2, backing your light up will make it fall across a large subject more evenly. In the basketball shoot above, the entire gym back wall was pretty evenly lit with just one flash, because it was at a pretty far distance from the subject.

So, distance helps, but it will cost you some f/stops as you back the flash up. A good way to get some cheap distance when shooting a group is to throw your flashes up into the ceiling if working inside. Not always possible (ceiling too high, weird color, etc.) but when you can it works great.

I like to move them a little away from the subjects (maybe as far back as the camera, on the 45's) and shoot them straight up. The place where the light hits the ceiling becomes your new light source. It is a big splotch of light not unlike an umbrella -- but further away because of the height. (More here from the example at left, in which the frontal light was just from one speedlight.)

Don't think of caroming the light off of the ceiling -- think of placing your light source where you want it. The hotspot will work as your source without the angles needing to match up precisely.

Tommi, from Finland, asked about this, too. I like to shoot them straight up, from right below where I want my light source to be on the ceiling. If I angle the flash and try to bounce it, I am likely to get some direct spill -- not pretty.

So, backing up and ceiling bounce are two options. Both require power -- you will be working at 1/2 to 1/1 power to get a decent aperture. Be ready to wait for recycles for a few secs between frames if you are using small strobes.

The third trick is to "feather" the light (if you are not bouncing off of the ceiling) by aiming it a little away from the near side of the group. So, if your light was on the left side of a five-person group you might want to aim at the person on the right side instead of the one in the middle. Maybe even at the area a little in front of the person on the far right side.

This way, you are trading angle for distance. The person on the left is closer to the flash (and thus would be hotter) but the flash is aimed somewhat away from her. So the light is not reaching her efficiently. So now she is not as bright as she would normally have been.

If you try this out a couple of times and do a few test shots, you'll see how easy it really is. The closer your flash is to the group, the more you are gonna have to change that angle away from the nearest people to get even light. But it totally works.

Another quick cheat: Place the people in darker clothing (and/or with darker skin) on the side of the group nearest to the light. Sneaky, but that works, too.


All or Nothing

Phillip, from Harrisburg, PA (USA) writes:

"You are shooting a model, at dusk. You only have 1 speedlight, which will not shoot at less than 100% power. It will fire off camera though. What would you/could you do in this situation?

This could benefit some newer people who have some hand me down equipment. My first speedlight was a SB50DX which didn't work at anything less than 100% on my camera!"


Phillip, that is one case where always getting 100% from your equipment is not necessarily a good thing. That "manual dial down" ability is the most important capability to look for when shopping for a flash. But free beats the heck out of perfect, and I would not go so far as to advocate someone turning down less-than-ideal hand-me-downs.

There are a few things you can do to fix this problem. But bear in mind that they are all band aids -- you will just be bleeding excess energy from the flash each time it pops. So make sure you have at least 6-7 seconds of BS to spew to your model between shots while you are recycling to full power each time.

The first two tips are similar to those offered to Rebecca, above. First, back that flash up to bleed power. Back it up and additional 40% (i.e., from 5 feet to seven feet) and you will lose a stop. Add another 40% distance for another stop, etc.

But that will also make your light look smaller -- and harder -- to your model. So you might want to weave in some extra BS about how her skin is so good it can take hard light. No worries -- you'll have plenty of time to talk with those full-power recycles.

A better idea is also related to the evenness thing. Feather your light -- up. Tilt that umbrella up and bleed some power that way. You'll also get a nice gradient down your model's body. Yet more BS material while that flash whines away interminably.

A third thing you can do is to knock down the flash with some neutral density gel. You can get all different strengths in the Rosco sample packs, or just buy a 20 x 24" sheet (~$7.00) of one-stop ND gel and stack multiple pieces as needed.

Better yet: Get 1/2-stop ND gel and stack those for the ability to get partial stops of power out of your flash. Mind the heat build-up, though, by leaving a little air space between the flash and the gel(s).

Another quick fix: take a sheet of typing paper and make a primary diffuser to knock down the light before it gets to your umbrella. Put a piece of tape on the top and bottom of the paper, and tape it to the sides of your flash in a big "U" shape.

Yet another fix: Next time you get hot and sour soup from your local Chinese joint, save the container. Not only does it make a great, <$2.00 substitute for an unnamed, overpriced diffuser, but it will also knock a stop or two off of your flash before it goes into the umbrella. Just cut an "X" slit in the lid and friction-fit it to your flash as shown.

Bonus: The light in your umbrella will be more even this way, so your model will look better. Note: Yet more BS material for the wait between flashes.

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So, there's QnA week one. I am stoked at the large selection of questions we already have in the bank, and look forward to being able to get to as many answered as time permits in the future.

If you have more questions, just stick them in the comments of any of these QnA posts. I will moderate the comments and discussions that are on-topic to this QnA post, and reserve the new questions to be added to the crop we already have.