wide2tele Loc: Australia

I never said you should not display them.
It's totally up to the photographer to decide if they wish to display them or not.

Tom Hungerford Loc: Thomaston CT

A ring light will give you one dimensional light. Very uninteresting. One soft box and a reflector will add much more creativity.

Tom

GoofyNewfie Loc: Kansas City

One good place to start:
https://strobist.blogspot.com/2006/03/lighting-101.html

MrPhotog

Actually, that law applies to point sources of light, without reflectors or concentrating lenses.

There are different formulae for linear light sources ( such as 8’ fluorescent tubes) and sources which have a large radiating area, such as a diffuser or umbrella set-up, or a bounce-flash.

You are correct that useable lIght does diminish with distance, but a square of the distance is not always the appropriate factor.

Simple experiment: candle versus an umbrella, or large, diffused light source. Use a lightmeter and check exposure of a subject 4”, 8”, 16”, and 32” (roughly 10, 20, 40, and 80 cm). With a candle you can measure the differences and they will pretty much match the theory. Not so with umbrella lighting. You’ll hardly notice a difference.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

Good n question and some 1/2 good answers and some unnecessary arguments over word usage.

In lighting aesthetics and technology, some physical "laws" do apply and are obviously not legal statutes or complex advanced science. There are just some basics that photographers should know about. I will explain and how they apply to ring light usage in portraiture.

In inverse square law simply states that the volume of light diminished with distance so a small ring light that is principally designed for macro photograhy, may not necessarily have an sufficient power to accommodate a situation where the subject is beyond closeup range. If some depth of field is required, a low-powered unit may not provide for sufficient stirring down at moderate ISO settings. There are, however, larger and more powerful ring light configurations that have significantly higher power.

Another issue concerning the inverse square law is the depth of lighting. A ring light provides coaxial lighting which is totally "flat" and non-directional. When mounted on the lens, it is the antithesis of off-camer lighting and thus can not be raised above the camera to shed some light on the background area so the fall off of ligh may seem more pronounced.

Another set of basic rules has to do with distance and softness or hardness of lighting which are important aspects of portraiture. There is also a correlation between the relative size of the light source to the subjects. Without too much techno-babble, here's the concept. The closer the light source is to the subject, the softer the effect- the further the harder the effect. The smaller the size of the light source in relation to the size o the subjects the harder the effect and the larger the light source the softer. This does not mean you can turn an umbrella setup into a spotlight by placing it further from the subject but distance will have subtle effects.

So...to kinda answer the question, lots depend on the effect and style YOU wish to achieve and you must assess the usage according to the equipment at your disposal and the shoot conditions and types of portraits want to create, and keeping the aforementioned theories and starting points in mind.

There are trends and fads that divert from traditional portraiture. If you want o make traditional classic portraits, ring lighting would no be my first choice. There are and were trends in fashion photograhy where ring lighting became popular as well as simple on-camera flash. The light is flat, in terms of non-directionality of light, and in the latter case, a shadow would appear on solid backgrounds. There was always the expected background falloff of light that some call the "black hole effect" resulting from underexposed backgrounds. This kinda fashion shooter trend crossed over in portraiture and some photographers, art directors and clients like the effect.

With small on-camera relight the office I personally dislike are central catch-lights in the eyes, sometimes a distinct kinda donut-shaped reflection in the eyes or eyeglasses that some suggest a kind of manic look in the eyes. Unless the subject has a perfectly symmetrical facial structure, coaxial flat light offer no control over sculpting the face with lighting or dramatizing the total effect with shadows. Simply because I do not prefer this kind of lighting for portraiture, that does not make it bad or anythg to be excluded or perps modified for a better result.

There are LARGE ring lights both in electronic flas and LED versions. There were designed and manufactured to provide coaxial lighting for larger format camera and to provide a LARGER ligh source for more softness and more efficient spread of the beam of ligh produced. There are smaller ring lights that have 3 or 4 individual flash tubes rather than circular flash tubes. This allows the photographer to shut down 1/3 or 1/2 of the flash tubes and provide a bit more direction of light to render better texture or dimensionality in macro work. Another technique is to defuse or block off 1/2 of the circular flash tube's beam with a piece of frosted material or a black gobo.

In my studio, I have several ring ligh and use them mostly for commercial and industrial work- they are indispensable for shoot things like printed circuit boards and small mechanisms where shadows would obscure important details or components. I do not routinely use them for portraits, but there may be some saving graces or potential!

Sine the Covid-19 pandemic and the need for television broadcasting production to set up "work form home" or improvised studio setups, the LED ring light has become popular In a condition where technicians could not be dispatched to private homes, the broadcasters were sent a DYO setup whereby an i-phone or any smartphone could be mounted in the center of the ring light and provided somewhat usable lighting. Some of the DIY kits contained a second or third matching ring light that could be set up on a stand and used off-camera to add dimension and depth of lighting in the background. These ring lights are about 12 inches in diameter and emit relatively soft and even lighting. Since there is no central lamp or tube, there is no hot spot and the periphery of the beam is somewhat like feathered light.

If I had to McIver something and all I had were ring lights, I could work around the issues and shoot a portrait, however, I would not purchase new ring light for portraiture. I'm sure there are photograher who are using ring lights effectively for some kind of stylization in portraiture. In my own studio, I sometimes get a request for a headshot for a model or an actor with "no shadows" or retouching- they want to see the real deal, warts and all, at the agencies. The flattest I go is butterfly lighting and it is perfectly revealing and acceptable.

I hope this helps!

User ID

I didn’t say that. Acoarst it falls off, but not as drastically as the inverse square law. Inverse square is about point source radiation and simple geometry of areas.

Studio lighting devices are contrived to be the very opposite of point sources. So the rate of fall off is much gentler. It’s also less simplistic to calculate as the dimensions of the large sources must be compared to dimensions involved in the scene that’s being lit.

IOW a four foot soft box becomes a small source if it’s thirty feet away, but
for a table top product shot it has little to no fall off. For a portrait it has close to negligible fall off, just enough to render a sense of dimension.

Silverrails

Yes, I have a Softbox complete Set-up, Just looking for opinions on other forms of Portrait Lighting, their may be times when that Softbox or A Speedlight Flash may not work, so, just considering other possible options.

wide2tele Loc: Australia

Anything else has limited use.
Softboxes can be used for a host of different lighting setups and subjects.

Silverrails

Yes I have a Nikon SB-800 Flash and a 32"x32" Gordox Softbox Kit.
Now I want to purchase a good quality 6'x8' Backdrop, I think Cloth will be better than Vinyl.