Where does this "looks like flash" idea come from? Has anyone ever tested continuous vs strobe?

(this question is only about the visual look or appearance, not about power, convenience, features, temperature, etc)

Howdy. I live by the motto that light is light, and regardless of the source they all [generally] are guided by the same principals and laws of physics. However, I was speaking to a well known lighting expert in my city and he told me that continuous/hot lights actually look slightly different. "In portraits, hot light has a subtle nuance to it, a subtle glow or smoothness because the quality of light is different at the source". I found this hard to believe if the bulb whether continuous or flash is modified the same way, under the same power. Then I thought, the different in using flash vs continuous is the shutter speed! Flash tends to kill any type of ambience while continuous lights can allow for a slow shutter speed to soak up the ambience. Perhaps this is how some old school film photographers achieved a "glow" in their portraits.

So I ask, has anyone actually conducted a test on this topic? I wish I could, but don't have continuous lights at the moment. Why is it that flash "looks like flash" and continuous light doesn't "look like continuous". Is it because the key light on the face is usually too strong when people use strobes? Where does the "looks like flash" idea come from if light is light after all?

Why is it that the extremely powerful hot lights used in cinema don't look artificial, whether using hard light or soft light, they always look very well balanced.

I will start at the last comment first. Cinema lights usually don't look like flash because almost all of the people on stage, even the guys, have likely been blotted or had their faces (and bald spots) powdered. I used to sing in a large choir and when we were filmed to be televised nationally they powdered all the guys and checked on the women to see if they needed help as well.

Now to the original question. All lighting looks different. A studio strobe looks different from a speedlight. A strobe from one brand will have a slight different look from another companies strobe. Saying continuous lighting looks different from a flash is too generic of a statement to mean much at all. To start with, simply the differences in the temperature of the light alone would make the types of light look different.

Nogo wrote in post #18450765
I will start at the last comment first. Cinema lights usually don't look like flash because almost all of the people on stage, even the guys, have likely been blotted or had their faces (and bald spots) powdered. I used to sing in a large choir and when we were filmed to be televised nationally they powdered all the guys and checked on the women to see if they needed help as well.

Now to the original question. All lighting looks different. A studio strobe looks different from a speedlight. A strobe from one brand will have a slight different look from another companies strobe. Saying continuous lighting looks different from a flash is too generic of a statement to mean much at all. To start with, simply the differences in the temperature of the light alone would make the types of light look different.

Regarding the powder, is it a heavy amount of powder or just as much as necessary? I know makeup is important but still, even with perfect make-up I can often times tell when flash is used. It just has this artificial look to it. Maybe that means lots of DOF, perfect skin, face too bright, not sure yet.

When you say a studio strobe looks different from a speed light - I agree this may be true when using them as bare heads. But I should've been clearer in the original post: I am speaking about when two different light sources use the same modifier, a medium soft box for example. In my mind, they would look nearly identical on the portrait. Again, I am talking about the quality of the light, not the temperature. EDIT: actually I changed my mind, I realized the cold/white look of a flash lacks the warmth of natural daylight (which is cold as well but not as clinically cold)

Perhaps cinema lights look much better because of the high dynamic range cameras they use. The immense shadow detail and lower contrast looks much better to me than the high contrasty look of a pop of flash on a DSLR.

I don't know how much powder is used. That is up to the make up artist. For photographing the main objective is just to eliminate shiny spots. Blotter paper should be enough for a quick session. An extended session in bright summer sunlight or under strong studio lights may require powder, but I am no expert at all on how to apply it. All I know is that the MUA uses a brush such as the ones you see the fingerprint experts use on TV. Long very limber bristles.

There are so many factors in the quality of the light, I am just saying any factor changes the look of the light in some way even if just slightly. Slight differences such the position of the bulb in the modifier make a difference so there are probably many reasons a continuous light looks different from a flash. The duration of the light is just one of them.

moodlover wrote in post #18450772
Regarding the powder, is it a heavy amount of powder or just as much as necessary? I know makeup is important but still, even with perfect make-up I can often times tell when flash is used. It just has this artificial look to it. Maybe that means lots of DOF, perfect skin, face too bright, not sure yet.

When you say a studio strobe looks different from a speed light - I agree this may be true when using them as bare heads. But I should've been clearer in the original post: I am speaking about when two different light sources use the same modifier, a medium soft box for example. In my mind, they would look nearly identical on the portrait. Again, I am talking about the quality of the light, not the temperature.

Perhaps cinema lights look much better because of the high dynamic range cameras they use. The immense shadow detail and lower contrast looks much better to me than the high contrasty look of a pop of flash on a DSLR.

Light is light. However, what gives light it's character depends on the size of the light source, the modifier, the distance, etc. In cinema the light heads can be pretty large and they tend to be farther away from the subject than what you would do for portraiture. As far as bare lights go however, it really comes down to the difference between how hot lights are designed vs strobes. Hot lights will often have a focusing lens that can be de-focused to remove the harshness of the light, which will removed the heavy micro-contrast you would otherwise get from a bare light. Beyond that I think it's more about how the lights are used.

Scatterbrained wrote in post #18450783
Light is light.

THANK YOU for that! If you put a strobe tube in the same instrument as a incandescent fixture & adjust the light the same way, I doubt that anyone could tell the difference between "The looks".
The thing about strobe is that most people don't know how to do that & so don't do it.

I challenge any scientist to articulate any objective characteristics which are measureable,
which makes a 3200K constant (continuous) light source to be ANY different from a xenon flash tube which has a CTO gel over the flashtube to convert its color temperature to the same 3200K effective rating.

When both are modified in the same manner they are two similar light sources, and 'continuous' vs. 'flash' is NOT AT ALL a distinguishable difference!

Light is a myth anyway.

It's really very high frequency electromagnetic radiation.

moodlover wrote in post #18450747
(this question is only about the visual look or appearance, not about power, convenience, features, temperature, etc)

Howdy. I live by the motto that light is light, and regardless of the source they all [generally] are guided by the same principals and laws of physics. However, I was speaking to a well known lighting expert in my city and he told me that continuous/hot lights actually look slightly different. "In portraits, hot light has a subtle nuance to it, a subtle glow or smoothness because the quality of light is different at the source". I found this hard to believe if the bulb whether continuous or flash is modified the same way, under the same power. Then I thought, the different in using flash vs continuous is the shutter speed! Flash tends to kill any type of ambience while continuous lights can allow for a slow shutter speed to soak up the ambience. Perhaps this is how some old school film photographers achieved a "glow" in their portraits.

So I ask, has anyone actually conducted a test on this topic? I wish I could, but don't have continuous lights at the moment. Why is it that flash "looks like flash" and continuous light doesn't "look like continuous". Is it because the key light on the face is usually too strong when people use strobes? Where does the "looks like flash" idea come from if light is light after all?

Why is it that the extremely powerful hot lights used in cinema don't look artificial, whether using hard light or soft light, they always look very well balanced.

Light is light. People like to come up with cute stories about it. Not trying to be rude, maybe just a bit cheeky, but we all know someone like that.

What is hot light? Is that the temperature or color? Does it matter? Nope. The subtle glow occurs when the exposure of the light is soft and more akin to a fill level of light, not a key or high key light, and that's not even taking into account the apparent light source size and shape (which matters probably the most). So a cooler temperature color flash, in a warmer ambient light setting will look sterile and not glow as much, especially from a small apparent light source that is very far from the subject (such as bare flash pointed directly at the subject from over 20 feet away). Compare that look to a flash or strobe that is in a 60 inch modifier and powered down to only be fill and gel'd to be warmer to match a warmer ambient light and you'll see a warm glow. Has nothing to do with being continuous or not, or "hot" or "cool" (those two things can be changed in post anyways, and that in and of itself says a lot about it).

If you want to take in more "ambience" (I assume this means increase ambient exposure) then the camera is set to do that by increasing overall exposure. The key to blending flash to ambient is to also adjust flash exposure so that it is not also increased maintaining the same ratio. So if you want more ambient and less flash, you increase ambient exposure via camera settings, and lower flash output on the flash itself (such as setting it to be a fill light and not key light). If you want less ambient light, you set the camera to stop down ambient light and expose the flash however you want. The flash doesn't do anything to ambient light (unless flash overpowers ambient light, but you control that).

Lots and lots of tests on this subject in this very forum; with stories, in the "show your lighting & results" thread.

The lights in cinema are not big hot lights, they're often LED too, hard or soft, the reason they look balanced is because (1) they have makeup on that doesn't reflect and conceals; (2) post-processing is still applied, they don't release footage SOOC. If you look at RAW footage of a film in a BTS scene and compare it to the end result, they look virtually nothing alike.

+++++++++++++++

Here's a test for you of my own:

Same equipment used, same comp almost, same distance, same light, etc. The only difference will be amount of fill light used and light temperature and white balance. No modifiers. Bare flash (small source, fairly distant from subject even).

Ex 1:

"Looks flashed"

Under-exposed ambient in normal daylight via camera settings
Flash is bare; no gel
Flash is bare and directly pointed at subject
Flash output is set to fill (no shadow caused from my light, only filling shadows)
Due to apparent light source size, the light is a little harsh, even as fill light (spectral highlights on subject's face, makes it look flashed to me in this context; powder would have made that softer)

IMAGE LINK: https://flic.kr/p/RXwm​6o

IMAGE LINK: https://flic.kr/p/RY2u​Do

People do tend to use strobes differently from tungsten sources in a number of ways, as mentioned above, which makes comparison difficult without carefully controlled conditions.

The "light is light" argument does, mostly, point to some basic truths about the ability to, at least in theory, get similar results in conditions which don't take advantage of things only strobes can do (freezing motion, providing enough light to eliminate or reduce ambient even in direct sun, use apertures you could not practically achieve with continuous light, etc.).

But the spectrum of light coming off Tungsten is more at the warm and IR end and less at the blue and UV end. I tend to notice that the skin is more "penetrated" by strobe light in a way which makes makeup look less strong (as if the subject is wearing less makeup). Tungsten is a bit kinder when there is no makeup.