Does "quality of light" exist? Not talking about soft or hard light...

I am interested in input from those who are experienced about whether or not different light sources can change the perceived "quality" of the light in the final photograph. I put it in quotes because I'm not referring to whether or not the light is soft vs. hard. I am referring to whether one light when modified and set up the same exact way as another light, can look "prettier" or "higher quality". Very hard to define what that means but maybe it exists? Maybe not?

Like a $20 home depot hotlight vs. a $1200 Profoto D1 in studio portraits...both modified the same exact way with a regular 3x4' softbox will one of the pictures subliminally appear more beautiful than the other? If so, would it even be noticeable?

Odd topic, but if anyone has input/proof would really appreciate it. I think the answer is no, but different lights can have different uses/flexibility but the way they fall on the subject and reflect is all the same once put into a softbox. Thoughts?

In short: can one light appear nicer than another, if they are both modified and set up the same exact way?

I think the answer is No, and everything else you see and hear is a bunch of marketing hype. The only thing I notice that really changes the look of the light is the size of the light source.

moodlover wrote in post #16968147
I am interested in input from those who are experienced about whether or not different light sources can change the perceived "quality" of the light in the final photograph. I put it in quotes because I'm not referring to whether or not the light is soft vs. hard. I am referring to whether one light when modified and set up the same exact way as another light, can look "prettier" or "higher quality". Very hard to define what that means but maybe it exists? Maybe not?

Like a $20 home depot hotlight vs. a $1200 Profoto D1 in studio portraits...both modified the same exact way with a regular 3x4' softbox will one of the pictures subliminally appear more beautiful than the other? If so, would it even be noticeable?

Odd topic, but if anyone has input/proof would really appreciate it. I think the answer is no, but different lights can have different uses/flexibility but the way they fall on the subject and reflect is all the same once put into a softbox. Thoughts?

In a word: No.

In more words: Modified light is modified light. My cheapo YongNuos do not make "worse" light than AlienBees or even the most expensive pack & head system if modified the same way and color corrected the same way.

Different lights offer different things such as power, flexibility, portability, reliability, speed, convenience, etc but no they don't offer any intrinsic betterness of the light itself.

The difficulty though lies in getting them set up exactly the same way. A home depot light can't be put in all soft boxes due to the heat while other soft boxes are designed for "hot lights." The positioning in the soft box has an effect as does the shape of the bulb itself. A speedlight with its fresnel lens isn't going to spray light all over the inside of a soft box the way a strobe with its bare ring shaped bulb will. Even with an umbrella, a speedlight is positioned relatively high compared to a studio strobe so it doesn't fill the umbrella as evenly, creating a different light pattern.

So there are variations in quality due to the difficulty (sometimes impossibility) of modifying the exact same way but if you can get this exact same modification AND placement relative to the subject then you will see zero differences.

Lights that do not emit a full spectrum would potentially lead to color issues. Some have noticed color temperature changes when output power changes.

BTNorris wrote in post #16968363
Lights that do not emit a full spectrum would potentially lead to color issues. Some have noticed color temperature changes when output power changes.

This. I've never been happy with the spectrum from the fluorescent or LEDs in my house. I've learned to somewhat compensate for it in Lightroom, but sunlight, incandescent, or strobe is still best.

There's also a number of other issues like refresh rates, flash duration, power and build quality, consistency (amongst others)

moodlover wrote in post #16968166
In short: can one light appear nicer than another, if they are both modified and set up the same exact way?

Absolutely. If you use fluorescent lights, especially those that are driven at power-line frequency, you will notice some severe problems with color and intensity depending on the shutter speeds you choose to use. You can get ranges of color shift and intensity across a single image when using 50 Hz or 60Hz fluorescent lighting.

The same kind of thing can occur with other similar lighting that depends on exciting a gas with electric current.

SkipD wrote in post #16968417
Absolutely. If you use fluorescent lights, especially those that are driven at power-line frequency, you will notice some severe problems with color and intensity depending on the shutter speeds you choose to use. You can get ranges of color shift and intensity across a single image when using 50 Hz or 60Hz fluorescent lighting.

The same kind of thing can occur with other similar lighting that depends on exciting a gas with electric current.

But color and intensity can be corrected. Sure, it's a pain in the ass to do, but it doesn't make it worse on the subliminal level OP was talking about.

BTNorris wrote in post #16968363
Lights that do not emit a full spectrum would potentially lead to color issues. Some have noticed color temperature changes when output power changes.

Annoying but correctable.

Color temp, frequency and impact on shutter speed, etc. are technical not quality considerations.
As stated, if a light source, whatever it is, is placed in a modifier at the same position, the resulting light on the subject is the product of the modifier rather than the source.
That's just simple physics.

cdifoto wrote in post #16968428
Annoying but correctable.

Not always. It's not just a question of white point. I had some LED bulbs with a color temperature similar to incandescent, but some of the spectrum was missing so SOME objects with colors that would have reflected that spectrum didn't render properly.

While I agree with dmward's point, the question posed did refer to continuous and strobe lighting and asked if one could be "prettier."

But back to the OP: There are various reasons to buy a more expensive light, but lights of similar "style" should render similarly for all the reasons already said.

Coming back from theory to the real world...

A nice monolight with a nice softbox will give prettier light than any rig you can muster with home depot lights. Same for messing with strobes trying to fit them into a softbox which they were clearly not designed for. At the very least you don't have a modeling light.

If your question is practical and you're asking with intent to build a rig out of home depot lights, then save yourself the trouble and get a proper setup.

Although a light source in the proper position in a modifier will deliver the same light onto the subject it is important to qualify that photographic lights are superior to non-photographic lights for lighting subjects for picture taking.

Best example I can think of, from personal experience, is buying cases of expensive photofloods. We bought them because, for a period of time, they delivered true 3200K light. We could have gotten lots of lights for less money that would have delivered the same illumination on the subject. But the colors in the transparencies would have been far from what we wanted or needed.

As BT and Doc have pointed out. Even though the illumination on the subject may be the same, the photographic character of the light may be all wrong.

My answer is "It depends"

There are a lot of factors into play - for example, on the same softbox, you add a grid - the quality of light changes, because the direction is more restricted and less scattered.

When you use a polarizer, you again, restrict the light to wavelengths traveling in a particular direction.

Since white light is made up of multiple wavelengths ( think Rainbow) having more of certain color and lack or another will alter the quality of light and I suspect that would also be affected through a softbox - a simple experiment would be to put red light in a softbox and make a picture and then blue through the same setup to compare.

I am not sure if this is the answer that you were looking for, but it still relates to the "quality of light".

In some instances, the difference may be so subtle that for all practical reasons, it may not make a difference in situations that are mentioned in the OP.