Thursday, August 2, 2007

The Pictures are Inside Your Head

Full disclosure: I am totally looped.

I spent all afternoon and evening shooting for the DVD's, and am heading up to New York early tomorrow morning to have lunch with a couple of editors at PopPhoto, including Kathleen Davis, who edits the very cool PopPhoto Flash blog. I am also gonna buy a DLP projector for the seminars.

(Sorry, I shouldn't drop names. Ansel Adams always told me, "Never drop names.")

No he didn't, you liar.

(It's a joke. Leave me alone. I'm tired.)

Then go to sleep.

(I am. Soon. If you'll shut up.)

Fine.

(Fine.)

Told you I was looped. I did actually talk to Ansel Adams once. But that's another story.

By the way, that's not Kathleen in the photo. That's Kris, who was helping us out on a DVD shoot today. She was great.

Hers is the only photo you will see in this post, which is not about Kris at all. From here on, the pictures are all inside your head. It's Freaky Friday here on Strobist, and I want to take you on a little mental trip.

Come along, shall we?
__________________________________



A couple of weeks ago, someone posted to the Strobist Flickr threads that they had to shoot a photo in a candle-lit spa, and did not know how to approach it.

I answered them with a quick technique to use, but really did not go beyond the technicals. Today, I want to expand that and introduce you to the idea of first previsualizing, and then reverse engineering, a photo. The only pictures in this process, until you actually go out and execute your idea, are inside your head.

What I want to do is to think out loud (or at least in print) to share a process that I do several times a day. I enjoy these little mental exercises, and they give me experience at lighting scenes when I might appear to be doing something completely different. Like listening intently during a conversation.

("Three pops at half power? What do you mean? Were you even listening to me? What did I just say?")

Okay, back to the happy place.

How would you light it? The candles won't do it alone, obviously. But how do you make candle light?

The first step in previsualizing a photo is to imagine it as your eye would see it. Because that is the effect you are going to try to duplicate in a digital image.


What does candle light look like?

• It is not very bright. Pretty darn dim, actually. But your eyes partially compensate for it.

• It is warm, Very, very warm. Bordering on red. But again, your eyes partially compensate for it.

• It is flickery. But we cannot really address that in a still image.

• It comes from down low, because candles are typically lower than our eyes, as opposed to other light sources which are generally placed higher.


Are you starting to see an image in your head? Good. Study it. Remember what candle light looked like -- with your eyes -- the last time you saw it. That's our target. Let's see what we can do to get there.

General theory: We want to light the room to look the way that our eyes see a candle-lit room. Not the way a camera sees a candle-lit room. Big difference.

First variable: Light level. We are going to underexpose the scene. That is how we create a dark "key" to a photo.

Since we are working with flash, this is very easy to do by exposing the room correctly, and dialing down the aperture. We start with the shutter at the max sync speed, to save our ambient component for later. We will have to solve that, but let's take this thing one variable at a time.

So lets throw a light into the ceiling and underexpose it by two or three stops. We want darkish illumination coming from seemingly everywhere, just revealing form.

Does it look like crap in your head? Good. It should at this point. Let's hit variable #2, the color of the light.

We are going to have to significantly warm the light. At least a CTO gel. Maybe two, stacked on each other. You can do that, you know. We want reddish, very warm, dim light. And we want it darkly and vaguely defining the room.

For the sake of argument, I would start with a double CTO gel on our bounce-fill-even-lighting flash, off of the ceiling. If the ceiling is wooden, it'll warm the flash up a lot. So just one CTO if a wooden ceiling.

At this point, I am thinking double CTO, into the ceiling, at 3 stops down from the correct exposure.

Now, we make the candle light. This is warm, too. The candles likely come from low down. So I aim another flash down and bounce it off of the floor. Warm it just as much as the ceiling flash. But this one gets enough power to underexpose wherever the people are going to be sitting by one stop. More definition, but not fully exposed. And the light is diffuse, coming from down low.

(Obviously, the floor cannot be in the photo where the flash is bouncing off of it.)

We are getting close. What should be taking form in your head is a photo of the room showing the effects of candle light.

Is this making sense? If this sounds like I spent the whole evening smoking weed, I promise you I did not. And I have several tired witnesses, too.

So, now we have a room that is lit to "effect of candle light." What next?

We need actual candles, lit in the frame.

Here's the trick: We are going to place candles in the scene in a place to where they appear to be lighting the subject(s) in the same direction of the semi-bright warm light coming off of the floor.

This is called "motivated light." You have a light source that is there for subject matter only (the candles.) But your real light comes from the general direction (but off camera) as the visible "there-for-show" lights. (Which would be the candles.)

This is a classic technique that many of you geezers more seasoned shooters will recognize. It is taught in great detail in the book "Matters of Light and Depth," which is the photogeezer's lighting bible. This book is meant for motion picture guys. But it's Old Skool and Way Cool for still photogs who want to understand light.

So, how's our mental picture coming? Yeah, the candles are working for us. But where do we expose them?

That's easy. First of all you should darn well know by now how we are gonna control the exposure. We open up the shutter speed (your camera will likely be on sticks for this shot) until the candles look right.

If this sounds hard, it isn't. Remember, the candles to not have to light the subjects and the room. So we are no longer asking them to do the impossible - to be subject matter and and light source. We have already done the latter with flashes.

They just have to brighten up until they look convincing as light sources. So they only have to be bright enough to be lights as subject matter.

You see the control? You are lighting on two separate internal planes (flashes do the work, candles get the credit.) So you have total control over the relative brightness of the candles in the scene. Just slow down your shutter speed until those suckers look right.

If you have them positioned right, the floor bounce light will look convincing as candle light. Move the candles or the strobe to line them up as best you can.

One last tip: The bright candles are gonna make those weird little highlight flares by bouncing internal reflections around in your lens. You can help those two ways:

One, remove the front filter. Many internal reflections originate off of the rear surface of your filter. I do not care if it is a name-brand, prime, $80 filter. Get it off and watch the result.

Two, you'll do better here with a fixed focal length prime lens than a zoom. Fewer internal elements, less opportunity for internal light gremlins.

I am not guaranteeing a great result with this, mind you. It might totally suck. But this is exactly where I would start if I were making this photo. Then I would spot my problems and adjust from there.

More important, this is a little mental game you can play any time you want. You can light scenes in your head twenty times a day. Then, when you really go to light a photo, the process will be much more organic.

For better or worse, this is how photographers who light tend to think. Or at least how one of them does.

So, how many of you are still with me? Is the photo inside your head yet? Did the path to get to it make sense?

Is this kind of detour worthwhile, or is it the inane, caffeine-spiked ramblings of a sleep-deprived whackjob?

Hit me in the comments. Just remember that I will be unable to moderate them very often today, while up in NYC.

Good night.

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