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.IMAGE LINK: https://flic.kr/p/RXwm6o IMG_5233
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).
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)
by Martin Wise
, on Flickr
"Can't tell that flash was used"
Under-exposed ambient in sunset golden hour (warm temperature white balance) via camera settings
Flash is gel'd with a CTO gel (1/4th CTO)
Flash is bare (with the gel on it) directly pointed at subject
Flash output is set to fill (but even lower amounts of fill, no shadows caused from my light, barely filling shadows, just enough to get some features)
Even though the apparent light source is small and a little distant, the fill level is so low it doesn't produce spectral highlights, so it looks more natural and you just get a glow.IMAGE LINK: https://flic.kr/p/RY2uDo IMG_5208
by Martin Wise
, on Flickr