How to determine distance from KEY light to subject

I've read a lot about where the key light can be positioned as far as
angle and elevation are concerned, but I'm uncertain as to what
distance I should place it from the subject. I'd appreciate some
advice.

I've read a lot about where the key light can be positioned as far as
angle and elevation are concerned, but I'm uncertain as to what
distance I should place it from the subject. I'd appreciate some
advice.

Your exposure should be based on your fill light. From there it all
depends on how contrasty of a lighting ratio you want.

I've read a lot about where the key light can be positioned as far as
angle and elevation are concerned, but I'm uncertain as to what
distance I should place it from the subject. I'd appreciate some
advice.

they need to as close as you need to get the lighting effect you desire.
With modern lightboxes and scrims you get them as close as you can till you
see it in your view finder then back off a couple inches.

for moderately reflective surfaces such as human skin commercial photogs
tend to use a light source twice as big as the subject.

in many considerations of photography there a give and take, to get some
effect you loose on something else, stop down a lens and get more depth of
field but need more light or longer shutter, open up to get a shallow depth
of field, use a slower shutter but risk camera shake.

In lighting you similar effects. Move light in close and you have a shallow
depth of light, (consider the inverse square root on exposure, now if your
light is 2 feet away and your subject has 16 or 18 inches across will the
left shoulder have the same exposure as the right, one mistake folks make
with window light images is they put the window too close) but it is softer
as the size ratio of light source to subject can be 1:1 or better. Move it
out and get more depth of light but more contrast, smaller spectral
highlights, more rapid highlight to midtone to shadow transition.

sometimes the equipment suggests or dictates usage styles, they used to
place those huge 2,000 watt spot lights as close as 18 inches (and with barn
doors and feathering could actually achieve a soft light. Those 18 inch
parabolic flood lights were used typically about 3 feet away. When they
introduced strobes and umbrellas you had to be careful to not get the damn
shaft in the image.

this reply is echoed to the z-prophoto mailing list at yahoogroups.com

I've read a lot about where the key light can be positioned as far as
angle and elevation are concerned, but I'm uncertain as to what
distance I should place it from the subject. I'd appreciate some
advice.

Your exposure should be based on your fill light. From there it all
depends on how contrasty of a lighting ratio you want.

what if he wasn't using a fill light?

the fill based exposure system is a very old fashioned concept, predicated
on methods of development and exposure designed for black and white
photography, and hi volume studio portraiture.

with black and white photography you had the luxury of varying the
development times, so the rule was, "expose for the shadows and develop for
the highlights."

modern color, especially transparency, and even more critical with digital,
requires excellent highlight exposure. If you blow out your highlights you
will never get anything but white.

the fill based system required a darkroom or lab that was aware of what you
were trying for. They had to adjust the print exposure to print down to the
level of highlight detail. If you moved your lights around for more or less
contrast, more or less dramatic imagery your lab had to recognize and adjust
the exposure of the print cause the fill light was set and never changed.

However a system of exposure based on the highlights would mean that the
photog controls the image from the camera level, he places and meters the
key light, and adjusts the reflector, or if you are still a fill light
user... and sets that level to capture the effect desired. the lab is
instructed to expose for the best highlight and print the entire series the
same, if the photog is doing their job then each print will come out as
intended, without depending on a lab guy to pay attention, to fix things.

this reply is echoed to the z-prophoto mailing list at yahoogroups.com

I appreciate your advice.

I've been reading (in "Fred Archer on Portraiture"), that the key to
subject distance should be determined by observing the quality of the
highlights produced on the face. If the key is too close, the
highlight will look "washed out;" if the key is too far, the highlight
will flatten out and won't notice, and if the key is at just the right
distance you should see a well-defined highlight giving good
modelling.

The book was written in 1948 - perhaps the advice applies only to
tungsten lighting (I'm using strobes)?

Thanks again.

this reply is echoed to the z-prophoto mailing list at yahoogroups.com

what if he wasn't using a fill light?

Then he needs to learn about portrait lighting.

the fill based exposure system is a very old fashioned concept, predicated
on methods of development and exposure designed for black and white
photography, and hi volume studio portraiture.

Did the laws of physics change and nobody told me?
It's not old fashioned, it's the right way to do things and get
predictable results every time.

modern color, especially transparency, and even more critical with digital,
requires excellent highlight exposure. If you blow out your highlights you
will never get anything but white.

What moron does portraits for people on slide film?

the fill based system required a darkroom or lab that was aware of what you
were trying for. They had to adjust the print exposure to print down to the
level of highlight detail. If you moved your lights around for more or less
contrast, more or less dramatic imagery your lab had to recognize and adjust
the exposure of the print cause the fill light was set and never changed.

I never had to tell my lab anything. The negatives were properly
exposed so that automated equipment made perfect prints.

I've been reading (in "Fred Archer on Portraiture"), that the key to
subject distance should be determined by observing the quality of the
highlights produced on the face. If the key is too close, the
highlight will look "washed out;" if the key is too far, the highlight
will flatten out and won't notice, and if the key is at just the right
distance you should see a well-defined highlight giving good
modelling.

The book was written in 1948 - perhaps the advice applies only to
tungsten lighting (I'm using strobes)?


the shape of light matters little where it came from. So the type light
makes some light styles easier than others. IE: strobes are much better for
large soft systems cause you need a lot of power to push through a layer or
two of fabric and spread it around like a sprinkler system, whereas hot
lights, and lots and lots of it wrapped in layers of fabric are a fire
hazard. spot lights make good use of tungsten cause it concentrates every
bit of energy and focuses it right on the small area you aim it at.

for a through explanation of how light source size and distance effects the
rendering of a subject I highly recommend Dean Collins 3D lighting. he
breaks things down into separate highlight ratios and shadow ratios,
spectral highlights to midtones, penumbra transition rate etc. This short
but packed video explains why a photog should be more concerned about their
highlights, how they render shape and texture, and that what may appear to
be a problem with shadows is usually a symptom of a bad highlight.






this reply is echoed to the z-prophoto mailing list at yahoogroups.com

what if he wasn't using a fill light?

Then he needs to learn about portrait lighting.

so there is no good lighting without a fill light? Is this like a religious
dogma?

what lights do is place highlights, that is all they do, they are light
sources. using a fill light means you have more than one source of light
coming from more than one direction.


the fill based exposure system is a very old fashioned concept,
predicated
on methods of development and exposure designed for black and white
photography, and hi volume studio portraiture.

Did the laws of physics change and nobody told me?
It's not old fashioned, it's the right way to do things and get
predictable results every time.

The point behind a system of doing things is to get predictable results.
The laws of physics haven't changed, but when a system of beliefs comes a
religion then you can't see any other way.

modern color, especially transparency, and even more critical with
digital,
requires excellent highlight exposure. If you blow out your highlights
you
will never get anything but white.

What moron does portraits for people on slide film?

A. Morons that work for Time/Life Magazine, Nat Geo, Sports Illustrated, any
of a thousand magazines and stock agencies in the day.
B. Morons that have a client that comes in and says that corporate wants a
portrait but their specs say they require a transparency.
C. Morons that wanted control of their imagery, what they get on film is
what they shot and not what some other moron in a lab whom they never met
decides to do with their image.
D. Morons with digital cameras cause those CCD and CMOS chips act more like
transparency film than negative.


the fill based system required a darkroom or lab that was aware of what
you
were trying for. They had to adjust the print exposure to print down to
the
level of highlight detail. If you moved your lights around for more or
less
contrast, more or less dramatic imagery your lab had to recognize and
adjust
the exposure of the print cause the fill light was set and never
changed.

I never had to tell my lab anything. The negatives were properly
exposed so that automated equipment made perfect prints.

So you never shot a rim light profile? or deviated from your standard 3:1
lighting?

Look, I spend most of my life with a fill based system. I used a separate
power pack for a bank of heads that was my fill system. I heard of folks
who put their fill light bank on a voltage regulator so their f/6.3 was 6.3
as sure as IBM sent out dividends to widows and trust fund orphans. Heck I
even had these way cool plans, I was going to make a hi key background wall
with four flash heads smoothly lighting this coved wall, and that white wall
was also going to be my fill light for the low key other side.

But the fill based system is predicated on a basic fact. You set your
exposure based on your threshold exposure, the minimum exposure to get
maximum black. And once set it never changes, you install a screw on the
lens barrel so the idiot assistants can't change the f/stop.

Then if you want a more dramatic lighting you bring in the key light closer
to raise the ratio. move from a 3:1 to a 5:1 for a dark dramatic image, a
rim light profile. But your lab man must recognize that is what you are
doing, cause if they give you the same shadow detail as the 3:1 kiddie pics
you are going to get a washed out hi-light. your perfectly exposed machine
prints still require a lab guy to adjust exposure on each neg, usually using
a video analyzer. That's why we paid pro labs 60 -70 cents a 4x5, cause we
needed someone intelligent hitting the key pads to adjust.

Fill based systems made perfect sense in black and white days, they were big
on shadow detail, you gotta get it on the neg, so you made sure it was on
the neg, the highlights you could develop for by pulling the neg, the base
exposure would develop just as fast as the highlights but end early, the
dense parts would keep building so you could pull the neg before they got
too dense, or you could print down with a flatter paper, or you could reduce
the neg.

In color, in digital you only have one chance to get detail in the
highlights, when you shoot it. Yeah sure with RAW capture and 16 bit files
you could have two stops leeway (which is getting close to color neg
results) but still.

Fill light systems made perfect sense back in days when the only artificial
light was hot lights, which required highly specular spot lights and
reflector bowls to redirect, to concentrate, to focus every bit of light
onto the subject cause film was slow, lenses were slow and it took an awful
lot of light to expose an image, soft lights were just not practical, in the
beginning days of photography, which was invented before they invented
electrical lights, they used soft light, ONE light systems, northlight
windows or tents to shape the light that same way, of course in those days
the client had to put their head in a brace to keep from moving too much.

So as soon as artificial lighting came practical, (arc lights in metal boxes
with barn doors) they invented blown out specular highlights and then
invented the fill light, to FILL the shadows they created. And ever since
this kludge fix has been THE WAY a portrait must be done. There can't be
any other way, or you're just not knowledgeable in the proper way.

Look, commercial guys don't use fill lights, they hang a big assed softbox,
twice as big as the subject, they get large diffuse highlights and enough
detail in the shadow areas cause the spectral to midtone and the midtone to
transition is so smooth and gradual. Its based on the laws of physics...

zeitgeist, what is the purpose of attempting to conduct an intelligent
dialogue with Randall Ainsworth?

"zeitgeist" writes:

what if he wasn't using a fill light?

Then he needs to learn about portrait lighting.

so there is no good lighting without a fill light? Is this like a religious
dogma?

what lights do is place highlights, that is all they do, they are light
sources. using a fill light means you have more than one source of light
coming from more than one direction.

... etc. ...

zeitgeist, what is the purpose of attempting to conduct an intelligent
dialogue with Randall Ainsworth?

I still disagree with him.