Wednesday, July 12, 2006

Pretty, Shiny Things

I previously mentioned that I was in the studio the other day, shooting wheat beer. The light painting idea was a bust, and I had to bail to plan "B."

Even though I was using the bigger flashes for this job, I wanted to use this opportunity to show you a new lighting technique. You can also use this as a chance to exercise your "reverse engineering" skills.

The problem when shooting a dark, reflective object like a beer bottle is that it mercilessly throws all of your light right back at you. It's hard to hide from a curved reflector.

In this early photo, which was a quick, CYA shot at the beginning of the session, you can see the problem. The softbox reflections are hot, and the rest of the bottle is pretty much without any useful detail.

To change the way a highlight is reflected back to you, you have exactly two options: You can change the surface quality of the subject, or you can change the appearance of the light source itself.

The former can be achieved with "matte spray," which I did not have. So I chose the latter.

Before I explain how I did it, stop right here and try to figure it out yourself for a moment.

--------------------------------

Now that you may or may not have it all figured out, I will tell you that I am using the same softbox as in the harder-light photo above.

The difference is that I am now double diffusing the softbox, which is actually a strip light. (No mystery there - it's what was available in the studio.)

In doing that, I am controlling the "specular-to-diffused transfer."

The what?

Yeah, I thought that might throw you. But no worries, you already know this. You just don't know the terms.

In any 3-d, lit object, there are three zones of light: The shadow, the diffused highlight and the specular highlight. There are also "transfer zones" between the various areas.

The shadow is the part that is not lit. On the earth, that'd be the side of the planet experiencing night time.

The diffused highlight would be the part receiving light from the sun - the daytime folks.

The specular highlight would be, say, the reflection of the sun you would see in a lake while flying in a plane.

The diffused highlight-to-shadow transfer zone would be the areas of the earth in twilight.

But there is also a specular highlight-to-diffused highlight transfer, which is what we are trying to control in the beer bottle. That'd be that sharp edge of the softbox reflection. And we want to soften that.

As I said before, matte spray would do the trick. It would change the surface quality of the bottle. But it'd also make the bottle look a little weird. So I prefer to alter the quality of the light.

What I did was to place a sheet of Rosco Tough Frost (Made by the same folks who make the gels) in between the bottle and the softbox.
It is kind of difficult to see, even with this scener shot, but what it does is to soften the edges of the softbox as seen from the beer bottle's perspective.

("Tough Frost" is pretty much what it sounds like it is. It is translucent, but not transparent. And if you are careful with it, it lasts through many, many studio shoots.)

This softening also shows up in the reflection was are trying to control. It is still a hard, glass reflection. But it is a hard reflection of a soft lighting transition. It is important to place the diffusion material very close to the subject, or you lose the effect.

Here is a detail from the final photo, with the target area seen in close-up. (Edit: Sorry about the confusion earlier.)

Nothing has changed about the bottle. But the light is different, and I got the desired by altering the light.

I could have helped this along by getting the beers really cold in the fridge and letting them sweat a little in a warm studio, but I had no fridge nearby. This would have also visually suggested "cold," in addition to altering the reflective surface quality of the bottles.

You'd definitely want to do that in an ad shot.

This diffusion technique works great for shooting small, reflective objects. Instead off tough frost, you can use tracing paper or tissue paper, like we did in the macro studio. The point is to diffuse the light. Or to diffuse the edges of an already-diffused light source. You can completely redefine the (apparent) reflective quality of any surface this way.

I like to tape the back edge of a diffusion material down and support the front, like a little lighting lean-to. Then I put a light above it and shoot through the raised space in the front. Works great. I'll do an On Assignment shot like that soon.

For the record, this is all on a table and there is also another softbox behind the setup, backlighting the wheat stalks.

So, just some new techniques to think about.

Besides, you never know when you are going to be called upon to shoot a high-end shot of a beverage, anyway...

Next: Pool Portrait


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24 Comments:

Anonymous R. Janoski said...

Another way of solving the problem and David comes very close to doing it is simply "tenting" or tent lighting the product.

When using tent lighting it's important to remember that you can still use some subtractive lighting techniques to bring modeling and definition to the object being photographed.

Another trick of the trade when shooting bottled items and glasses that have liquid in them is to "back" the product with reflective foil, white paper or white strip. The typical example is the bottle of beer and frothy mug photo where the beer has that wonderful amber glow.

July 12, 2006 1:51 PM  
Blogger jgbrownie said...

photoflexlightingschool.com has a good example of what you are showing here. There are lots of other good lessons. They talk specifically about their equipment but it is good general knowledge.

July 12, 2006 2:31 PM  
Blogger TrappedLight said...

David,

How does this technique compare to using a softbox with an internal baffle, creating double diffusion within the softbox? Thanks.

July 12, 2006 2:57 PM  
Blogger EssPea Photography said...

Is it a sin if I like the second image better?

It was cofusing reading though. I was under the impression the 'bad' one was the first picture and that I was trying to figure out the second (to which I correctly guessed 'strip light, but isn't that obvious?'). I figured it out after the dotted line though.

July 12, 2006 3:18 PM  
Anonymous Aric said...

That's all about control. With the baffle, it sits only where the manufacturer tells you it's going to sit. By using your own diffuser, you buck the system and say NO! I want my highlight to look like MY WAY, not the way you repressive corporate overlords want it to.

Or something like that.

Basically, companies like to give us lots of options and features to make our lives easier (and 90% of the time, it does just fine) but for that 10% where you need to work outside of the parameters of the product, a little ingenuity is required.

July 12, 2006 3:22 PM  
Blogger jmpsmash said...

ESS,

i too like the second image better.

i wonder if strobist posted the final product. i don't think so. i think the last photo is the cropped version. perhaps when he does show the final product, it will be better than the second one.

July 12, 2006 5:06 PM  
Anonymous Nick Decker said...

I'd have to opt for the second picture, too. The double diffusion thing doesn't work as well for me, in this case.

I'd also think that the blood-thirsty newsprint would make the double diffusion version even softer?

July 12, 2006 7:29 PM  
Anonymous StanTheMan said...

@nick-

Actually, its the second one down that would be ruined by newsprint. The dot gain would make the bottles go black. The tamed highlights version would repro much better. That's one reason you want to keep your internal contrast at a magable level.

StanTheMan

July 12, 2006 9:31 PM  
Blogger MagikTrik said...

Mr. Hobby, first you show us a video about using softboxes & then specific instructions on how you used a softbox, did the "softboxes are evil" thing change when I was sleeping?
Just kidding, thanks for the info.

July 13, 2006 2:48 AM  
Blogger Roland Simmons said...

Video? What Video?

July 13, 2006 3:58 AM  
Blogger MagikTrik said...

@Roland Simmons, the post right before the beer bottle one was a link to a portrait lighting video at Sports Shooter. I almost didn't see it too because I'm not usually expecting to see more than one post when I come here, you know?

July 13, 2006 4:04 AM  
Blogger Roland Simmons said...

Oh, that video. Thanks for helping me out there majiktrik. I watched that a couple days ago.

July 13, 2006 4:23 AM  
Anonymous Dansellbuddy said...

I like the composition on the second one better, and I feel that if the lighting in the first was applied to the second, it could be even better.

July 13, 2006 2:20 PM  
Blogger www.kirktuck.com said...

Dear Mr. Strobist,

When I used to shoot beer we always, always, always lit it from behind. The bottle and the liquid are largely transparent and the best way to do it (besides shooting it on a cyc or on a white background) is to cut out a foam core or paper shape that mimics the size of the bottle, place it behind the bottle and then use a snooted or gridded light shooting into your little white reflector (placed behind the camera). It works with white wine, beer and bottled water, not to mention glasses and other transparent liquid containers. I'll try to dig up a sample to show you but pouring light on the front or side (regardless of which magic diffuser being used) is futile as far as adding volume and dimension to the product. I think a have a lit beer glass in my product gallery at www.kirktuck.com

Thanks, Kirk

July 13, 2006 2:33 PM  
Anonymous cothran said...

Here's a link showing what janoski was talking about - using white paper to backlight a bottle ( of chanpagne).

http://ritz.webphotoschool.com/Bouncing_and_Reflecting_Light_through_Glass/index.html

July 13, 2006 7:38 PM  
Blogger Fascist said...

Mmm.... hefeweizen... packed with yeasty goodness....

July 13, 2006 7:42 PM  
Blogger David said...

I probably would have lit it from behind also, but not without the lights he has setup. I like the diffusion, I remember when I worked in a commercial studio I had these big screens made out of pvc pipe with material stretched over them. they were 4x8' and I could set up a bunch of lights behind them.

The second photo looks better, but it doesn't acheive the goal because it doesn't say "wheat beer" and his job was to illustrate a story on wheat beer, not take pretty shots of a beer bottle. I think he did great with the wheat background and the light overall, though another strobe or two with snoots or grids from behind would have given it more pop.

July 14, 2006 10:01 AM  
Anonymous Anonymous said...

I think the tail-end of the above URL got truncated... it should be:

Bouncing_and_Reflecting_Light_through_Glass

tpuerzer

July 14, 2006 1:20 PM  
Anonymous Per Backman (Sweden) said...

Hi!
Thanks for a good lesson on ligting shiny objects - and I find it a good thing to get both versions of lighting so I can choose for my own pictures in the future.
Then I simply must comment on the wheat stalks:
I would say it's barley (not 100% sure because it's hard to tell from the pictures). Wheat dosen't have the "antennas".
However beer is usually made from barley so I guess it doesn't really matter :D
Cheers

July 14, 2006 7:54 PM  
Blogger ericrudd said...

>though another strobe or two with snoots or grids >from behind would have given it more pop.

But then it wouldnt' have been a beer ad then now, would it?

Gosh, I crack myself up.

Eric

July 15, 2006 8:25 AM  
Blogger espiros said...

Ericudd...

Yes, that made me laugh as well.

I will also point out that webphotoschool.com has a GREAT article on double diffusion (a technique I have brought to the "small screen" by using hot-shoe flashes with diffuser acessories along with 12 inch translucent diffuesers from Photoflex), although if you choose to subscribe to that site, be prepared to have photoflex/Olympus shoved at you constantly. Still, the lessons are very good, although David's work is every bit as valuable without shoving products at you.

October 10, 2006 12:52 AM  
Anonymous Anonymous said...

I'm a little late to the party here, but regarding all the messages about how the final photo (top one) would have been better if lit from behind... well, it looks to me like the bottles were getting some light from behind, presumably from the source backlighting the wheat (or barley, whatever.)

February 15, 2008 8:05 AM  
Anonymous Mark said...

Another nice trick to use when lighting glass, (especially clear glass) when using either kirktuck's backlighting technique or a large diffuser on the front, is to use a largish black card or cloth as a sort of 'anti-reflector' to give some 'shape' to the light on the object, usually at the sides to give better seperation from a white background. Essentially the black object is reflected in the glass, giving the appearance of an unlit area.

This was one of the few tricks for studio lighting I learned at college that survived the twenty years since.

May 24, 2008 12:40 AM  
Blogger BruceMolzen said...

Use a polarizing filter ?

March 18, 2013 4:49 PM  

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