Thursday, January 26, 2012

Q&A: Dealing with Glare from Dark Wood Backgrounds

Reader Jefferson, from California in the US, asked via Twitter:

"How do you deal with glare on dark wood in background for portraits? Is this covered in Lighting 101 or 102?"

Actually, it is covered in L102, if a little obliquely. And yes, pretty much any time you light into dark wood as a background you are gonna get some blowback.

But rather than look at this as a problem, I prefer to think of it as a feature
__________


So first, let's get some consistency in our terms. What Jefferson considers to be a "glare" is something I think of as a specular highlight. To me, a glare is what I can expect from the missus when I say something a little … insensitive.

But what we are really talking about here is a reflection of a light source in your background. And dark wood, with a typical satin (or worse) finish, has a very efficient reflective surface as compared to its true tonal value. So it is going to throw a light right back at you.

One way around this is to light obliquely, as in when you are dealing with glasses. But I think this is a missed opportunity. If you position a relatively soft light source (such as an umbrella) near the lens axis, you can get double duty out of it.

One, it makes a very nice on-axis fill light. And two, the specular from a soft light source is large in size and muted in intensity. Take this example:



This was one of many quick, run-and-gun portraits I did for a computer software company during a convention at a hotel. They were using the photos for testimonials in trade mags. We only had a few minutes to shoot each one, and we had to scrounge our backgrounds from what was available.

In this case, dark wood.

There are two light sources here, both speedlights. The key is an 43" umbrella, upper camera left. The fill is another umbrella, firing right over my right shoulder.

Glare? Yep, we got it. But is it controlled in size and intensity by the size of the light source we are using. And our shooting/lighting angle controls the location of the glare. Or, as I call it, the specular.

So we kinda harnessed it into a third light source. It is working in its primary function as fill. But it is also kinda like a background light. And a much-needed one at that. We would be in trouble with his shadow-side shoulder without it.

If you want an idea of how much trouble, check out the separation we are getting between his camera-right shirttail and the wall. That would be a big problem for us up top without the specular.

And once I am close to the proper position on the fill light, I can move the specular around slightly by raising or lowering my camera position slightly. Doesn't take much, either. Because there is a reflection involved, the angle doubles the result. If I move my camera down three inches the specular will appear to drop six inches.

That's very quick and easy to modulate when you are in a rush, as we were. Way better than constantly moving a light source.

To be sure, this would have looked like crap if our fill light was small -- say, a ring flash. The specular would have been much smaller, and way more intense. Not good. So this is one of those times you want to know enough to switch up for the desired effect.

Speculars are one of the most useful lighting controls you have. You can learn more about them in this section of Lighting 102.


__________

Brand new to Strobist? Start here | Or jump right to Lighting 101
Connect w/Strobist readers via: Words | Photos


Comments are closed. Question? Hit me on Twitter: @Strobist

19 Comments:

Blogger typingtalker said...

"If I move my camera down three inches the specular will appear to drop six inches."

If you move the camera down three inches, the specular will move 1.5 inches down the wall.

January 26, 2012 9:36 AM  
Blogger Nina said...

Very, very helpful. I had a similar issue at an anniversary party last year. The results were okay and the clients very pleased, but I studied the images and wondered what I could have done differently. Now I have some ideas.

Question, though: why is the subjects head lined up with the molding? Was that noticed or considered? Some of my early training strongly emphasized placing subjects head 'in a clean place', so that's something I notice.

January 26, 2012 10:40 AM  
Blogger Nina said...

Very, very helpful. I had a similar issue at an anniversary party last year. The results were okay and the clients very pleased, but I studied the images and wondered what I could have done differently. Now I have some ideas.

Question, though: why is the subjects head lined up with the molding? Was that noticed or considered? Some of my early training strongly emphasized placing subjects head 'in a clean place', so that's something I notice.

January 26, 2012 10:40 AM  
Blogger Jay said...

" Actually, it is covered in L102, if a little obliquely."

Nice little oblique pun you threw in here.

January 26, 2012 10:44 AM  
Blogger Miles Bintz said...

Have you ever considered using 1/4-1/2 CTO on the wood? (In this case your upper-left umbrella). I dunno. Since the finish on the wood is so reflective it's throwing back a very "white" light from the flash. Or maybe we're just used to rooms like this being lit by lamps and other forms of warm incandescent light. In any case, while the specular is under control, the color of the light still distracts me.

January 26, 2012 11:16 AM  
Blogger Harry said...

I'd like to think that some of the trees sticking out of peoples heads in photos go on to be moulding sticking out of peoples heads in photos.

January 26, 2012 12:30 PM  
Blogger SkippingStones said...

If you really are up for a challenge with wood......I just attempted a job for the Mouthrop Family, known for their amazing wood bowls and handicrafts. Check out their stuff at http://www.moulthropstudios.com/ed.html

Talk about glare and reflection! I basically had to create a black box and then tried to leave a slit in the black fabric just for enough natural light to get through and used a very long exposure. Any strobe/flash was putting to much light and you could even see me standing in the reflection of the bowl....hey how are you doing....there I am?
There actually is a PBS special documentary on this family and how hard it is to photograph their work...contact me if you want to try :)

January 26, 2012 1:18 PM  
Blogger Movies And More said...

Miles, the light on the wood is also illuminating the subject. The color change would occur on both background and subject.....

January 26, 2012 3:06 PM  
Blogger Kevin Camp Photography said...

I use the reflection for a kicker all the time with a single light setup. If you dont' want it change the angle of the camera to the ligth source so that the flash is not being directly reflected back at you.

January 26, 2012 3:58 PM  
Blogger Ian Mylam said...

Jefferson: David has explained how to work with the glare creatively and make a feature out of it. If you are still determined to remove it, there are a few options:

1. Glare from dark wood is direct reflection of the light source (as opposed to diffuse reflection, which occurs when the surface reflects the light in all directions equally). It is more of a problem with dark surfaces as the direct reflection is large relative to the diffuse reflection. The diffuse reflection carries information about the colour of the wood and its tonality, but produces no glare. The simplest way to avoid glare from the wood is therefore to move the light source outside the family of angles which produce direct reflection, so that only the diffuse reflection is seen from the wood. Or as David succinctly said: "light obliquely".

2. If for whatever reason it is not possible to do this, the second solution is to try fitting a polarizing filter to the lens. This will require more power from your lights of course, as the polarizer will act as an ND filter - you will typically lose 2 EV. The glare (direct reflection) may or may not be polarized, depending on the angle from which the camera is seeing the reflection (if the camera sees the reflection from an angle of 40 -50 degrees, the reflection is more likely to be polarized). If it is indeed polarized direct reflection, the polarizer should kill it.

3. If it doesn't kill it, the glare is unpolarized direct reflection. In this case, if you can change the camera angle slightly, you may be able to change the direct reflection from unpolarized to polarized so your polarizer can deal with it.

4. If you really can't change your camera angle relative to the light source, your final option is to fit polarizers over your strobes. This will ensure that your direct reflection is indeed polarized, so you can take it out with the polarizing filter on your lens.

January 26, 2012 4:22 PM  
Blogger Stewart Low said...

what kind of umbrella did you use?

January 26, 2012 7:31 PM  
Blogger Ameer Hamza said...

I was at a onelight with Zack in Dubai last year and he said he moves his camera so that the subjects head is at the center of the highlight.. makes a halo :D

January 27, 2012 7:30 AM  
Blogger Kevin Halliburton said...

Well done David, and well explained. Would Dean Collins refer to that as a diffused/ specular highlight? I had a situation once where I was lighting a large group against a gloss black painted cinder block wall and I used this technique. The problem was that the halo wasn't large enough to encompass the entire group. I stretched a 12 foot long piece of white rip stop nylon between two light stands and fired my umbrellas through it for fill. That was one gigantic diffused/specular highlight but it sure did the trick.

January 27, 2012 12:02 PM  
Blogger Frank said...

I had a related problem with wood throwing off my color. I was shooting some engravings in dark stained wood and even with the use of a white balance card, I end up with some unnatural looking colors The edges of the engraving tended to go purplish and no amount of tweaking in long-ins or standard RAW processing could totally make then go away. In the end, the client was satisfied but I wasn't. Just for reference I was shooting with one speed light camera right and natural light coming in through a window with a Canon 100mm Macro f/2.8. Maybe I should have moved the light to be more on axis but it wasn't really glare that was bothering me so much as it was color shift that looked a little like CA but in a the center of the subject where you would no except to see if. Anyway, thanks for the timely post.

January 29, 2012 12:26 PM  
Blogger alan said...

Memories of NPPA NSC in Warwick, RI about 7 or so years ago.

Thanks Dave.

January 29, 2012 5:18 PM  
Blogger David Hobby said...

@Alan-

Except there we were using just one light.

January 30, 2012 11:13 AM  
Blogger Ben Hollingsworth said...

Nina,

You'd normally want to avoid the molding coming through the guy's head. However, given the composition, I suspect that these photos were used as the entire page background for the testimonials, rather than as just an accompanying image. In that case, the text was probably printed in white over the right half of the image. The text would be hard to read if superimposed on detailed molding, so it has dibs on the empty space.

DH mentioned that he was working fast with what he had available, so I suspect that he didn't have a large enough empty space to put both the text and the dude in front of a smooth background.

February 03, 2012 11:53 AM  
Blogger bmillios said...

You also discussed this in some detail in the Strobist DVD, lighting the group in the cave auditorium with the reflective wood background.

February 09, 2012 10:05 PM  
Blogger Unknown said...

Another thing that I have done several times in the past when I want to cut reflections is to put polarizing film in front of the soft box, then a polarizing filter in front of the lens. You get much less light this way, but it completely kills the reflections.

February 29, 2012 5:05 PM  

Post a Comment

<< Home