DON'T MISS: Italian conceptual portrait photographer Sara Lando coming to US for two weekends of workshops in August.

Thursday, August 15, 2013

On Assignment: Radiance



"What should I wear?" asked Funlayo Alabi when we were touching base the day before I was to photograph her for the Howard County EDA.

"A white shirt if you have one," I said, wanting to distill the photo and feature her skin given she that she runs a boutique beauty products company.

Twenty years ago I might have said, "anything but white." But the more you work with lighting, the easier it is for you to control not only the contrast range but also the specific tone of a person's skin.

Even darker skin against a white shirt.
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Funlayo is a cofounder at Shea Radiance, which specializes in fair-trade shea butter products between the US and women from her native Nigeria. I love that the compass point for the company is as praiseworthy as are their products. I wish everything I bought had this kind of beneficial upstream result:



As for their traditionally prepared shea butter, I can't really speak to it. The only thing I rub onto my skin is the occasional barbecue sauce, and that is usually by accident.

But upon trying this stuff, my wife and daughter both reviewed it thusly: OMG.

Clicking on the Shea Radiance about page lands you at one of the first stops I hit while researching Funlayo before the shoot. By happenstance, the top shot of her is taken at the company's front door which is in open shade. As a result, her face is bathed in a large, indirect light source. So the reflections of the light source are in play.

Scroll down a bit and you'll see her in different light, direct-flashed (small light source) along with her husband Shola. The difference between the two is all down to light. The size and closeness of the light source — and the relative fill — both work together to create the tonal range of her skin in the photos.

Any time you light a three-dimensional object, the light will interact with it and produce three zones of reference. The area the light is hitting is called the diffused highlight. Exposed correctly, the object will return its true tonal value.

The area where the light is not falling is the shadow area (duh) and it will be darker. The reflection of the light source as seen in the object is called a specular highlight. (You can learn more about this in Lighting 102.)

Relatively speaking, and for lack of a better analogy, I'll go with a musical parallel. After all, there is a lot of crossover between music and lighting.)

So let's think of the shadows the bass, the diffused highlight as the midrange and the specular highlights as the treble. When lighting dark skin against a white context, I usually minimize the shadows and play more in the midrange and treble parts of the scale.

Just like with a piano and music, the result is that you shift the entire apparent tonal range upward, allowing it to easily fit well within your chip's sensitivity range. Even in the context of a white shirt and white background.

This is not an exposure thing, it is a specular management thing. Let's look more closely. Here is a zoomed-in version of the above photo:



As you can see, there are no deep shadows. The darkest area under her chin is still getting some fill from an on-axis light.

Her skin's radiance, to use a convenient word, is all about the speculars. And they are big and pretty much everywhere. Let's lasso them and bring them up (even if it temporarily results in an alien version of Funlayo) to emphasis the different zones:



This kind of stuff is important to us lighting geeks. The majority of the face is actually in specular highlight. It's almost as if the diffused highlight is the new shadow. But it's not — we have just shifted the whole tonal scale up while preserving detail in the white shirt and backdrop.

Interestingly, the specular is so wide that Funlayo's hair is actually interrupting it on the sides of her face. That is creating what looks like a shadow but is in fact just a missing specular highlight. In other words, it is an area of properly exposed diffused highlight. I.e., her true tonality.

It looks like a shadow, but is really a reflection of her hair in her skin which is in this case acting as a mirror of sorts.
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To create those huge, wide specular zones I am pretty much wrapping her with diffuse light, as you can see above. Note: this is from the same set but we have swapped the key from camera right (in the pics) to camera left (in the BTS). Just so no one is confused.

This is all speedlights — one inside each diffused umbrella, to be exact. The diffusion panels on the lights (Photek Softlighters in the front, Paul Buff PLMs on the sides) are important as they both even out the light and give it an edge to be able to control.

If you look at the side lights, they are tilted a little towards the camera to keep them from influencing the backdrop. I need that shadow to separate her, given the white vs. white.

The side/back lights are also wrapping speculars around her black hair, which would not have had nearly the visible texture and detail without them. Again, speculars as tonal shift.

And the amount of which you want to do this is both arbitrary and very controllable. It is all about apparent light source size (how big the source "looks" to the subject) which in this case is about light-to-subject distance.

As you bring them closer, the speculars will get bigger and the same light will get spread out over a bigger specular. Thus will each specular appear dimmer per square inch. Total control.

And to be sure, you might well choose to do it differently. It's really an arbitrary choice; there is no true right or wrong.
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So, just a little lighting sleight-of-hand to manage and compress the tonal range and reflections. After all, skin is the subtext of this photo and radiance is the word of the day.


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20 Comments:

Blogger Dusey said...

This gets me thinking about lighting while keeping the skin in mind. Are there good ways to light for blemishes or not so white teeth? I've always handled it in post, but now I'm wondering if there isn't anything to be done in-camera.

This is both a great way to show of great skin, and compressing the range is a helpful idea esp. when wedding dressing are involved!

(Sorry if this is a double post, had an error message)

August 15, 2013 11:09 AM  
Blogger lv pg said...

Excellent post David. I just finished a session of 100 football players, against a bright sky...and white uniform jerseys. Those with darker complexions are particularly difficult, as I generally have to bump up the light a bit for the skin. This often leaves me with hot spots on the jersey. I noticed most of your lights are high [shoulder height or higher]. They are also flat. are these factors key in the set up? [key as in important...not as primary light]

August 15, 2013 12:31 PM  
Blogger lv pg said...

On a side note...the security codes are getting more and more difficult to read. I now have to refresh 3 or 4 times before I can make out the letters or numbers.

Thanks for all.

August 15, 2013 12:32 PM  
Blogger David Hobby said...

@lv pg-

A big, on-axis fill light will solve many of your football player issues -- wearing helmets or not. For darker complexions, you are painting detail with specular highlight. The bigger the better.

On the captchas, totally feel you on that one. Beyond my control. And even so, I get dozens of spam comments a day. Le sigh.

August 15, 2013 1:12 PM  
Blogger jim "shu" carroll said...

david - i'm a fan and not worthy to carry your sand bags. but why the white background? feels like a strange choice to me.

August 15, 2013 1:56 PM  
Blogger David Hobby said...

@Jim-

The white shirt and background are reductive. It makes her skin (and, by extension, their product) more of the focus. And my sand bags are filled with gravel and REALLY heavy...

August 15, 2013 2:25 PM  
Blogger lv pg said...

Thanks David. With great respect and not wanting to turn this into a personal-help session...I use a large 10x10 white canapé [similar to an industrial EZ-UP] as a giant overhead fill, which drops the subjects 2-4 stops below ambient, then 2 strobes to bring the players equal to the ambient [1-key at chest height and a fill 1.5 stops under as fill placed lower]. Would bringing my key higher [head level] help solve the white shirt blowouts? Again, thanks for all.

7th try at this post. error, error, error.....

August 15, 2013 3:39 PM  
Blogger Ronnie said...

David, Can you show a close up of your set up with the Paul Bluff PLM, speedlight and diffuser?
Thanks!

August 15, 2013 5:12 PM  
Blogger David Hobby said...

Don't worry, it's not going to turn into a personal help section. I don't really do that in the comments. :)

I am not on the ground in your exact location, so I cannot tell you a specific fix. But I am pretty sure raising the key is not the answer. I would look more towards big (physically) fill lights from on axis and a tight ratio between key and fill.

August 15, 2013 5:13 PM  
Blogger David Hobby said...

@Ronnie-

Nope, sorry. Don't have that pic in hand and don't have time to shoot it for you. It's not rocket science. It is like a reflective umbrella with a diffuser on the front. Point the flash into the back of the umbrella. Nothing mysterious...

August 15, 2013 5:37 PM  
Blogger Ivor Houlker said...

Hi David - I'm a long time reader of your blog (since I first bought a flash) but this is my first time commenting -

I have to say this is an incredibly helpful post and really helped me get the specular highlights thing (especially with your alien illustration). I was shooting headshots today for someone and struggling with a white shirt on white, so seeing your post this evening was really inspiring and makes me want to try it again next time (I got her to change to a dark shirt instead).

August 15, 2013 6:51 PM  
Blogger Patrick Snook said...

David,

Thanks for your splendid, informative, and though-provoking tutorial.

What did your subject (client) have to say about her finished portrait?

Patrick

August 16, 2013 7:51 AM  
Blogger J.P. said...

"As you bring them closer, the speculars will get bigger and the same light will get spread out over a bigger specular. Thus will each specular appear dimmer per square inch. Total control."

It took me a minute to wrap my head around this one and I'm not at all sure that I have it now. Are you saying that, for a given light source, that source's specular highlight will get dimmer as you bring it closer to the subject since their skin will be reflecting a smaller area of the light source? If so, I'm not sure whether to say "Yeah, that makes sense," or to have my mind entirely blown.

August 16, 2013 8:48 AM  
Blogger David Hobby said...

@JP-

Yes, sort of! Think of a specular as being a reflection of a light source. The reflection naturally gets bigger as the light source is moved closer. And you net out the total AMOUNT of light falling on the subject by altering the exposure settings to compensate.

But the amount is now spread out of a larger apparent area (because the light source is closer, and looks bigger.) So each square inch of light source (and thus, reflection) carries less intensity.

August 16, 2013 2:55 PM  
Blogger David Hobby said...

@Patrick-

She was very happy. Which in turn made me very happy.

August 16, 2013 5:02 PM  
Blogger Michael said...

A Dean Collins video (2 parts) on youtube from World of Wonder TV series. youtube.com watch?v=146xPIAQh2k Not sure about links so add the missing bits.

Dean also explained the specular density as milk. In a glass (small area) you can't see the floor. Dump it out (same power, large area) and you can see the floor.

August 16, 2013 11:18 PM  
Blogger dom said...

As someone who has shot many dark-skinned grooms in white suits I read this greedily. It reminds me of your post on Dean Collins and his explanation using the billiard ball many times.

This helped me understand much better. Your descriptions were perfect. I was stunned by the hair shadow not being a shadow. I will definitely be rereading this many times.

August 17, 2013 6:43 PM  
Blogger Alexander Salde said...

I'm not sure if I'm getting this right. Instead of underexposing to create shadows, you created highlights this time to show dimensions. Great control, you either create shadows or highlights, depending on the skin tones.

August 19, 2013 1:20 AM  
Blogger FotoEnthused said...

"It looks like a shadow, but is really a reflection of her hair in her skin which is in this case acting as a mirror of sorts." Not getting this point? I see a key light in front of her locks with key aiming at her face and that is [i]not[/i] casting a shadow? If I drew an arrow wouldn't it go from the key to the lock of hair?

August 20, 2013 2:37 PM  
Blogger AL marcus said...

Great post with lots of gems as usual but, when I checked Shea Radiance's FB page, the link they posted about shoot uses the "alien version of Funlayo" as a thumbnail.

August 20, 2013 9:42 PM  

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