Wednesday, June 06, 2007

L102: Light Controls Overview

Today, we'll run through the various lighting controls to give you some context for later.

If these are all old hat, you may be in for more than you think. While they may sound simple to some of the more seasoned readers, I am discovering new techniques all of the time simply by studying these controls on a one-by-one basis. And I expect to learn a lot just by going through this process myself.

Each control has a range of possibilities, and offers both advantages and disadvantages that can be exploited or avoided for a given subject.


Lighting Controls Overview

1. Varying the Position
Changing the angle of your light position is what will allow your flash to define the three-dimensional shape of your subject. This is where on-camera flash fails us. It illuminates, but does not reveal shape. Getting your light off of the camera is the most basic control, so it is our first of the seven.

In addition to varying the angle of your light source, you can also dramatically change the effect of your light by varying the distance to the subject. In particular, altering the distance of the light to the subject as it relates to the distance from the light to the background.


2. Varying the Apparent Size of the Light Source
Note that I said "apparent." In photography, size does not matter. Apparent size matters. How a subject sees your light source will determine many things.

Size of light source can be altered by reflection off of a diffuse surface, or transmission through a translucent material. In addition to changing the apparent size of the light source, this will lower the intensity per square inch. This, in turn, will alter the way your light interacts with your subject.

We also will spend some time in this section talking about how the various surface properties of your subject come into play with your light source, and how to exploit those variables.


3. Altering the Relative Intensity
This is about balancing light - with the ambient, other strobes, lightning, glowing swamp gases, whatever.

It is not about the light level. That is easily compensated for by your exposure settings. The magic is in the relative light levels, and where you place your exposure settings with respect to your various light intensities.

This is a sticking point for a lot of people, so we are gonna hit it hard.


4. Restricting Light
Even more important than where your light goes is where it does not go. We'll be using various light restricting tools and exploring their effects in a methodical way.

Snoots, grids, gobos, cookies, (man-made and natural, oatmeal and chocolate chip) beam-width adjustment, feathering - it's all good. And we'll be hitting each one in turn.


5. Refraction and Reflection
You do it without thinking about it every time you zoom your flash. That little fresnel lens in the front bends your light to suit your mood. Or at least your lens. But there are other ways to bend light, and we will be exploring them.

Water, glass, mirrors, the extreme gravity around a black hole - whatever it takes.


6. Altering the Color
We're talking gels, gels, gels and more gels. Sure, white light is clean and predictable, but you have a whole color spectrum to play with. We'll make sure we get the basic color correction stuff in. But we'll also be looking at altering light color to develop a theme in a photo.

There are subtle things you can do, and not-so-subtle things. Most people are about as subtle as a ball-peen hammer when they start out with gels. But, just as the vinophiles will tell you, the real fun is in the slight variations.

Layering colors from a given family, complimentary color cross lighting, deliberate in-camera color balance shifting and more.

If you do not have a Rosco or Lee sample pack, beg borrow or steal one. And if you have a good source for said sample packs, please sound off in the comments. Especially out-of-US sources. I never, ever turn down a sample pack. Ever.

Go ahead. Offer me one and try me.


7. Time
Flash is impossibly brief, but continuous light is variable with respect to time duration. This gives us another creative lever to exploit.

Yes, light is light. But elapsed time adds a fourth dimension to a three-dimensional world, and offers results that simply cannot happen in a single instant.


_________________________________________

So, there you go. Seven straightforward concepts that together yield a world of possibilities.

We will explore them, dissect them, discuss them, occasionally curse them and finally get to know them on an instinctive level.

That accomplished, the goal will be to control them without letting them distract us from more creative thoughts.

When you tie your shoes, you do not consume mindshare by remembering that the little bunny has to go around both trees before it hops into its hole. (Can you tell I have kids?) You just tie your shoes while you are thinking about more important things. That's how you want to be when you position your lights, for example.

I have noticed a lot of questions popping up in the comments and the L102 thread on Flickr. So before we dive into "position," I will answer as many questions as is practical in the next L102 post, to minimize confusion going forward.

If you have a question, try to stick it in the L102 thread in the next few days. I'll go through and answer as many as I can, assuming they have not been answered by someone else.

FYI, I am teaching for the rest of the week at the Defense Information School at Ft. Meade in Maryland. It is put on by the US Department of Defense and Nikon. I have three days with a hand-picked class of six military photographers to teach an intensive course on location lighting. With such a luxurious amount off time and such a small class, I am chomping at the bit to get started.

That's right folks, join the Army and learn to light. ("Just sign on the dotted line, son, and those SB-800's are yours...")

Following that, I am headed down south with my family for a week to see my folks in greater metropolitan Umatilla, Florida. But I have some interesting stuff in the hopper all ready to go during my so-called vacation.

And two more big announcements when I get back.


Next: L102: Questions and Answers


__________

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38 Comments:

Blogger Joshua Targownik said...

In paragraph 1 you say "This is where off-camera flash fails us".

It should be "on-camera" right?

June 06, 2007 11:58 PM  
Anonymous Mark Sirota said...

head's up on a typo under "Varying the Position": "This is where off-camera flash fails us. It illuminates, but does not reveal shape."

That should say, "This is where ON-camera flash fails us."

June 07, 2007 12:00 AM  
Blogger David said...

Boy, am I glad I did not go to sleep after that little typo...

(Good morning, David. You have 516 comments awaiting moderation.)

Thanks,
SleepyDaveWhoPostsAt11:47pm

June 07, 2007 12:16 AM  
Anonymous Jeff Geerling said...

I bought three sample packs (which were free, but cost $0.01 to go through the system) along with some other supplies (to save on shipping) from B&H in New York - they're the perfect size for my Vivitar 285, and can be cut to fit most Nikon/Canon flashes...

http://www.bhphotovideo.com/c/product/45189-REG/Rosco_8807_Roscolux_Swatchbook.html

and

http://www.bhphotovideo.com/c/product/45184-REG/Rosco_8808_Cinegel_Swatchbook.html

There's also a store here in St. Louis for theater supply that gave me two Rosco sample packs for free after I told them I'd be interested in getting a few sheets of gels for the theater I help with.

June 07, 2007 12:16 AM  
Blogger Trent said...

AS someone who *hasn't* received his Rosco sample pack in the mail, I second the request for help finding sample packs that come to Canada. Anyone? Anyone at all? Bueller? Bueller?

June 07, 2007 12:22 AM  
Anonymous Rob said...

In Edmonton, Canada, I've been able to find Rosco sample packs from a company called "All Star Show Productions" on the west end.

http://www.allstar-show.com

They specialize in stage lighting for theatre stuff, but the gels work just as well on strobes...

June 07, 2007 12:46 AM  
Anonymous tpuerzer said...

For Canadians looking for filter sample books...

I've had good luck with William F White here in Vancouver. They stock both Rosco and Lee filters. And, they apparently have locations across Canada. Here is their website:

http://www.whites.com/

Also, I have ordered the sample books directly from Rosco US to my OFFICE address here in Canada (it looks a bit more "official" than ordering from my home I guess :) )

http://www.rosco.com/us/filters/swatchBookRequest.asp?type=roscolux

Hope this info is of some help.

June 07, 2007 1:36 AM  
Anonymous Jim said...

A lot to chew on... seriously, I sat down with a pop and some cookies to read this (was eagerly looking forward to it, hitting refresh on the main page for a day or so), so when I got to number four, it made me laugh.

This is great stuff though, and as someone who is new to the off camera lighting stuff, I really hope to learn a lot.

Rob, thanks for the tip on the gels in Edmonton! That's where I am, and I hadn't found any yet.

June 07, 2007 1:40 AM  
Anonymous Andrew Smith said...

I agree with the guy in the Strobist group on Flickr who suggested that people should buy gel sheets instead of hunting for the sample books. Getting sample books with no intention of buying sheets is wasting the manufacturer's time and money. We wouldn't like it if people did the same to us, for example spending hours discussing a job and then not booking us.

If you want CTO gels then buy a sheet of CTO. (I did.) It'll cost you a few pounds/dollars and it will last for years. Then if you want to experiment with other gels, go ahead and order the sample book, that's what it's for. Won't it be annoying, though, if you can't get one because of all the people ordering them just to get free gels?

June 07, 2007 1:55 AM  
Blogger SoulJah said...

"This is where off-camera flash fails us"

I think I got a little heart attack from that.

June 07, 2007 2:46 AM  
Blogger Donna said...

UK gell source - White Light - http://www.lxstore.com/ Contact them for Lee or Rosco samples.

June 07, 2007 3:45 AM  
Blogger tangcla said...

I was fortunate enough to pass the Rosco Australia head office on my way to Sydney, and managed to beg/steal (I think it was beg from memory) two gel packs. Otherwise I would not have them.
Ashamed as I am to say it - I have only used one gel so far (the 1/4 CTO)

June 07, 2007 4:33 AM  
Anonymous Robert said...

B&H is showing out of stock for now, but Adorama sells the sampler watch for $2.50. Sorry, but it's a US-only source.

http://www.adorama.com/ROSB.html

June 07, 2007 6:46 AM  
Anonymous derJake said...

For the german readers, you can get the sample pack here for only about 4€:

http://www.prolighting.info/product_info.php/cPath/172_173/products_id/9251

June 07, 2007 8:21 AM  
Blogger Steve Thurow said...

Dave Black has a good selection of 6. Altering color, on this months Workshop at the Ranch. http://daveblackphotography.com/workshop/06-2007.htm

June 07, 2007 9:17 AM  
Blogger Nandes said...

You can order those Adorama swatch books to Canada, if you want to pay over 30 dollars in shipping.

For anyone in/near Toronto, Vistek carries large sheets of most common Gel colours for about 7 bucks.

I've already bought CTO and shitty green.

June 07, 2007 9:25 AM  
Blogger mhakola said...

The Calumet in Cambridge, MA has them sitting in an oversized vase (pot?) over by Steve in lighting. I don't know if other Calumets have them as well...

June 07, 2007 9:29 AM  
Anonymous Anonymous said...

Another for the Canadian folks. Hiretech in Cambridge (Ontario) is not only sending me a sample pack for free, but they've popped it in the mail for free. That said, I feel strongly that we should also make a purchase or two. It seems unfair to them (especially since they were so kind to mail it for free.) Personally I'm looking forward to figuring out which gel actually matches the old-style flourescents around here. My green gel from the Midwest Strobist Kit is not a good match.

- Adam Benjamin

June 07, 2007 10:01 AM  
Blogger Eric said...

Charlotte, NC, USA - 'Metro area'
A great place to buy/get sample packs of gels is:

Barbizon Lighting Company
1016 McClelland Court
Charlotte, NC 28206

June 07, 2007 10:07 AM  
Anonymous very1silent said...

There is actually an eighth thing you can do with light: polarize it. Because polarization isn't directly detectable by the human eye (or by the sensors of the cameras most of us use) it only shows up as a notable effect when we use a polarizing filter on our camera as well, and is mostly useful in exaggerating or moderating the impact of the other seven effects.

June 07, 2007 12:22 PM  
Anonymous Anonymous said...

David, you may want to post a link to the official Q&A discussion on the right hand side or perhaps create a new topic for each blog entry/assignment and post the link in the blog entry.

Just a thought...

rpsip

June 07, 2007 4:36 PM  
Anonymous Holger said...

In Germany you can get it for EUR 2,50 at http://www.thomann.de/de/lee_farbfolien_katalog.htm?sid=45f638fd17c9bfec7da0d65621404262

June 07, 2007 5:35 PM  
Anonymous tpuerzer said...

Good points about not scrounging the free swatch books without any intent of buying the product.

I for one have a clear conscience. :)

When I went to William F White here in Vancouver I ended up buying several large sheets of CTO, Tough Frost, and some red, green, and blue gells (just because they looked "pretty"). I think I spent around $50 for all the gels, so I felt quite good about picking up some sample packs too!

The actual sheets are downright gigantic for Strobist purposes, but I figured they may come in handy in the future if I move up to some studio strobes. (And, besides, I was too embarrassed to just walk out of there with nothing but the free gels.)

Something for local Strobists to consider would be sharing the full sheets. You could easily divide them into four and still have plenty for most purposes.

Tony

P.S. The sample packs for the Lee filters are a bit bigger than the Rosco ones, so they are worth checking out if you adamant on just scrounging... :)

June 07, 2007 5:52 PM  
Anonymous Anonymous said...

David, I'd like to make some suggestions:

1) people uploading photos as assignments should describe (and preferably also shoot and upload) their setup;

2) you (or someone) should pick at least two assignment uploads:
a) a really nice one and explain what makes it really nice;

b) a mediocre one and explain what makes it mediocre and how it can be improved.

I know there was some of that going on with 101 (which I didn't participate in), but I think people could learn a lot from such critiques.

-rpsip

June 07, 2007 9:22 PM  
Anonymous Anonymous said...

I am really looking forward to the #7 portion especially: elapsed time!

June 08, 2007 10:01 AM  
Anonymous derJake said...

@holger: Yes but then you have to order goods for at least 25€.

Btw. is there text on the filters in these samplebooks? Or are they clear so that I can just tape them to my SB-24s and be happy?

June 08, 2007 4:12 PM  
Anonymous Anonymous said...

I'm not a vinophile, per se, but I am an avid Oenophile.

June 08, 2007 4:45 PM  
Anonymous Nionyn said...

derJake asked: "Btw. is there text on the filters in these samplebooks? Or are they clear so that I can just tape them to my SB-24s and be happy?"
Lee and Rosco samplebooks that I have seen do not have text on the gels themselves - they are interleaved with paper on which is useful information relating to the colour above it in the book (you can read it through the gel) such as name, number, transmission data and graphs, etc.
In any case it does not matter if there is text on them. At work (theatre) we label all our cut colour stock with the size/type of lantern for which it is cut, and the number of the colour. If we did not do this we could never keep track! :-)
At home I also label all of my cut colour with its number and the type of flash/grid/snoot for which I cut it. Providing the text does not cover a significant area of the gel it will make no more difference than moving your light a few centimetres. :-)
HTH
Nionyn

June 09, 2007 12:43 AM  
Anonymous Alex Krämer said...

@derjake
Thanks alot, I just ordered 1 pack. Thus I have a clear conscience, too, because I´ll be buying a couple of larger sheete for my studio flashes.

June 10, 2007 8:30 AM  
Blogger MFR said...

David,

Could you add a Lighting 102 link to the top right side menu of the Strobist homepage?

thanks
MFR

June 11, 2007 1:27 AM  
Blogger Tim said...

Looking forward to the course!

BTW, 'vinophile'? No, 'oenophile' - strange but true.

June 12, 2007 4:20 PM  
Blogger Bob said...

In addition to (the 8th method of controlling or presenting light) polarized light, there is also infra-red light (it plays havoc with digital sensors btw) such as might be found in food heating lamps and in IR films, and ultraviolet light sources.

June 12, 2007 11:39 PM  
Anonymous Holger said...

German readers that are fast can get a gel set for only postage costs in this thread on dslr-forum: http://www.dslr-forum.de/showthread.php?t=207247

June 15, 2007 3:09 PM  
Anonymous Anonymous said...

We sell Lee sample packs at L.L.Lozeau in Montreal (Quebec) for 5 bucks + taxes. Well worth the investment :)
www.lozeau.com

July 10, 2007 5:10 PM  
Blogger orcmid said...

Fascinating. A great review of the 7 elements. Not the same as being in the seminar though! Heh.

David, a small request. Would you go into your Blogger "dashboard" for this blog and change the options on comments to show a complete date instead of just the time -- there is no decent way to correlate the comments and the timespan over which they have been produced. For some reason, just having the times is eerie.

August 19, 2007 1:24 PM  
Blogger Terri said...

I'm very late to the game, but I know where Umatilla is!!! Even been there (made sure I didn't blink on the way through).

September 15, 2009 5:13 PM  
Blogger Gary Soucy said...

You must be a god David, because people make typo's all the time! Thanks for a great blog!

June 03, 2010 7:27 AM  
Blogger RyanUnk said...

I recently bought the Lumopro 180 which came with free gels. Will these be enough or should I still get a sample pack? I'm new to all this and I'm not sure what I'll need.

March 20, 2014 7:22 PM  

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