Light for your photo studio. Constant and pulsed light sources The difference between constant light and pulsed light

More and more often, debates arise about what type of lighting to choose for studio lighting: constant or pulsed? Previously, mainly only pulsed light sources of various modifications were used, and constant light sources were huge and expensive.

But today, the cost of permanent studio lights is starting to fall and their sizes are already comparable to similar pulsed ones, so this type of lighting has become increasingly used for studio lighting. In order to understand which light source is better, you need to understand in more detail the advantages of each type of lighting.

Pulsed light and its advantages:

1 . Great power. Pulsed light is much more powerful than constant light, this is due to the fact that with constant light the source reflects photons the entire time the shutter is open, and pulsed ones are able to accumulate a large amount of energy and release it in a split second until the flash fires. Therefore, under any circumstances, pulsed light sources will always produce more power.

2. Small sizes. The power of pulsed light does not depend in any way on its size; you can place the brightest lighting comparable in intensity to the sun in a 100 gram box. While constant light sources directly depend on size, the brighter the lighting, the larger the equipment.

3. Power supply. For both types of light source, the usual power source is batteries. Photo flashes can receive energy from ordinary AA batteries, but constant light sources are also regularly upgraded, so there are now battery-powered constant studio light sources on sale, although their power is not comparable to pulsed ones.

4.Color rendition. The color rendering index of pulsed light sources is about 100, while for constant ones it fluctuates around 95. Naturally, the higher this indicator, the better the lamp illuminates colors. Also, xenon lamps have a good color temperature of about 5500 K in daylight, this is a significant advantage.

Constant light and its advantages:

WYSIWYG – this acronym literally means “What you see is what you get.” This function is almost the key to the benefits of constant light. Because a photographer doesn’t even need to take a photo to understand how the photo will turn out. The artist immediately sees the lighting and, if necessary, can immediately correct it.

Advantages of working with light sources with low power.

Low power is not always a disadvantage; sometimes it “plays into the hands of the photographer.” For example, for photographs of still life or food, you can safely shoot without using shutter speed and get good bright photographs as a result. Quality of light. Constant light is softer and has a slightly better quality than pulsed lighting; more precisely, it is more natural. Ability to work with video. Of course, we must not forget the fact that with constant light sources you can shoot good quality videos. As you can see, both studio light sources have their advantages and disadvantages. Today, the consumer chooses from three types of constant light.

There are occasional debates online about what type of lighting to use. Traditionally, photography has always used different types of pulsed light because constant light studio lights were very heavy, very expensive, and consumed a lot of electricity.

But now, as the cost of constant light begins to fall and we see more and more powerful, even-spectrum, daylight-matched lighting products appearing on the market, the question of the benefits of constant light is once again becoming relevant.

“Light painting”, but how much light is enough?

Perhaps you are new to lighting and want to spend your money on buying light as efficiently as possible, or at least briefly familiarize yourself with this topic. In this article I will try to give a brief overview of the possible options and criteria for making a decision. Today we will compare the advantages of each system.

Pulsed light

1. Power!

Pulsed light sources will give you much more light output than constant lights at any comparable cost, size, or any other parameter. Why is that? Because a constant light source must reflect photons from objects into the lens as long as the shutter is open. A pulsed source can instead store as much energy as needed in a relatively short time, and then release large amounts of energy easily and instantly.

Let's use a little arithmetic to demonstrate this idea. Let's say you have five 60-watt halogen lamps. You get about 5500 lumens of light, 17-18 lumens per watt of power consumption. Since the light is constant, every second this 300-watt source will emit 5,500 lumen-seconds of light. Lumen seconds can measure the emission of light regardless of duration.

1sec., f/9, ISO100. The white balance of the light source is from 3500K to approximately 2950K. The dark strip has the same view illuminated by natural light.

Take a pulse source with a xenon gas discharge tube that produces about 100 lumens per watt. We use a relatively weak 60-watt pulse and assume that the manufacturer did not cheat with the indicators and the flash electronics are highly efficient. If we multiply lumens/watts by watt-seconds, we get lumen-seconds. So the lumen-second output would be around 6000.

Well, it's quite a bit higher than constant light! Yes, but keep in mind that all those lumen-seconds will actually be emitted in about 1/2500 of a second. Let's take lumen seconds, divide by seconds, what do we get?

6000/ 1/2500= 6000*2500 = 15,000,000 lumens! In reality the light output will be closer to 10,000,000 lumens due to optical and electronic losses. This makes it easy to overpower the sun, illuminating large rooms or hills or waves for a short moment. After all, we are engaged in photography - so we only need a short moment to take a picture.

1 sec.,f/9, ISO 100. You could use 1/250 sec. with approximately the same result. Compared to the previous photo, this one is 3.4 stops brighter!

Since energy is the product of force and time, a 160 Watt-second monoblock stores 160 Joules in capacitors, and a 300-Watt fluorescent tube uses 300 Joules of energy in one second. Twice the power and ten times less light!

So if you need a lot of power for a big job or want to overpower daylight, the best option is to use a flash light.

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Pulsed light allows you to have the sun in a package the size of a coffee can. You can light up a room like on a sunny day with a source that fits in your hands and weighs a hundred grams. If you are doing or planning to shoot outdoors, pulsed light is much more convenient.

To create a constant light that's about the same power as a pulsed light, you'll need to use several high-power Fresnel lamps, which consume about 4-20 kilowatts, weigh about 25 kg each, and cost thousands of dollars, yet produce an output of about 100,000 - 500,000 lumens. It's this combination of power and convenience that makes pulsed light something that won't be replaced any time soon.

They are not as huge as cinema lights. Although there are even fewer.

In terms of compactness, long fluorescent tube lamps do not fold down to travel size and definitely need shock protection in addition to the set. On the other hand, a meter-long softbox can easily be disassembled into a truly compact size.

3. Battery powered

For both pulsed light and flashbulbs, small self-contained batteries are a common power source. LED light is constantly being improved, so that there are already real battery-powered constant light sources, but the power of their light is not yet comparable to the power of pulsed sources. With batteries, you can go anywhere with three, four or five spot lights. For work on the road, this is indispensable.

Look - no wires! Many editorial photographers use flash kits for shooting in any conditions.

Flash units use AA batteries, or you can connect a high-voltage booster to speed up recharging. Lithium battery packs with a built-in inverter allow you to take your studio light anywhere, just like camera flashes. This is especially appropriate for small, rugged all-in-one PCs like the AlienBees.

4. Color

The spectral emission of xenon gas discharge tubes is such that they have a color rendering index (CRI) of about 100. CRI is a measure of how well the light illuminates colors without altering them due to peaks or valleys in the spectrum of the emitted light.

The closer it is to the continuous spectrum (regardless of color temperature), the better. The index for incandescent lamps is also 100, but for other constant light sources, such as halogen lamps, fluorescent lamps or LEDs, it is no more than 95. By the way, if you are looking for constant light, know that a coefficient of 80-90 is “good” , and 90-100 is “excellent”. In general, it is better to choose light with a coefficient of 91 or higher.

CRI>93, but at $8 per lamp. Color accuracy doesn't come cheap. And it still falls short of a regular flash.

In addition to excellent color rendering, xenon gas discharge tubes have a coating that gives them a daylight color temperature of about 5500 K, which ensures their applicability in a wide range of situations and adds another advantage to those already described.

5. Price

The cost per lumen-second (or watt-second) is much lower for pulsed light. The same applies to a large extent to the power and color requirements, which are also difficult to achieve today at a reasonable price with constant light.

Fluorescent light appears to be most effective with T-5 bulbs, which produce 5,200 lumens with a CRI of 93, and compact fluorescents, which produce 4,800 lumens with a CRI of 91.

You can buy two flashes for the price of the lamps and ballasts in this picture!

A good manual flash can be purchased for less than $100, and with TTL it costs about $200. Four powerful T-5 lamps will cost about $35, not counting the lamp itself and the electronics to operate it, which will add another $150 to the cost. This is if you collect everything yourself.

Cool Lights and KinoFlos costing between $500 and $1500 are no brighter than a flash. A 160-watt pulse monoblock costs less than $250. Adding the cost of a 12x48-inch stripbox, even from an expensive manufacturer like Lastolite, still won't match the cost of a quality fluorescent light.

Constant light

It appears that pulsed light is superior to continuous light in all directions. But is it? We haven't considered all the factors yet. Let's look at the benefits of constant light.

1.WYSIWYG

“What you see is what you get” (from the translator - this is what the abbreviation in the title stands for). With constant light there is no need for a modeling light, which generates a lot of heat and may limit you from using some light modifiers. You will immediately see exactly what the camera sees.

This can be a great help when learning to work with artificial light as you can move the light around and immediately see the result without having to shoot the shot at all.

It so happened that I used a modeling light as a permanent light in this shot, but any old fashioned table lamp could have taken its place really.

The ratio of light from sources directly in front of your eyes. No flash meter, no need to shoot in manual mode, just switch light settings until you like the result. And then adjust the aperture and ISO on the camera. One can only dream of such a learning process!

And your model will see what happens. Without sudden flashes of light everywhere - she may just have to get used to the high light levels.

2. Do it yourself

If you like to do everything yourself, then it will be much easier, safer and perhaps even cheaper to follow the path of constant light. A homemade fluorescent source can be assembled for about $150-200. A flashlight with several powerful compact fluorescent lamps in a large housing will cost about $200-250.

Compared to buying a pulsed light, the price is comparable. Compared to trying to disassemble, remodel, or make one yourself, a pulsed light source is a safety factor like night and day. No high wattage, no high voltage, no capacitor banks to worry about, no discharge channel.

Although in principle it is possible to assemble an inexpensive pulsed light source yourself, if you are not an electrical engineer, it is better to leave this to specialists. And don't forget that fluorescent lamps contain mercury vapor!

Almost everything you need for self-assembly - almostKinoFlo. Of course, not for $200, but still cheaper than the four-digit price of the original.

Even if you are not a DIYer, constant light still has huge potential for “alternative uses.” Want KinoFlo? Buy a greenhouse light for $150. Want as much light as possible? There are countless old lamps and lamps being sold for a couple of dollars. Unlike pulsed light, there is no reason to only use light specifically designed for shooting. Although pulsed sources may be more useful for photography, they are quite a significant investment.

3. Advantages of low power

Lower constant light output is not always a disadvantage. If you like to take bright pictures, but with an open aperture and a shallow depth of field, then constant light will suit you well.

If you're shooting food, produce, still life or other static subjects, aperture won't be an issue since you don't need to use motion-stopping shutter speeds. The light can be adjusted to your liking and the shutter speed won't matter much. This can be done with pulsed light using a neutral gray filter, but it's still good to see what's in focus!

Straight from the camera. Is it possible to determine whether the shutter speed here was a full second long or 1/250 s? I can not.

4. Light quality

This is a very subjective point and we can only talk about personal impressions, but perhaps you have noticed that there is some difference in the quality of softened pulsed and constant light? Personally, I have always found the quality of constant light more pleasant.

Perhaps because there is “real” dispersion with constant illumination over the area, and not falling towards the edges as with pulsed light with software. This, of course, applies primarily to long fluorescent lamps. LED panels are usually not big enough to see this effect, but I think it's the same.

Others say that light is light and from a physics point of view I agree with them. But the constant light also has a certain soft clarity that I cannot explain.

5. Video

The video capabilities of constant light should also not be overlooked, especially today, when more and more photographers are asked to shoot video with DSLRs. The ability to use existing light for video shooting can be a competitive advantage for a potential client with extensive needs.

You can also experiment with using a constant light source on your camera to see how the lighting of your subject changes as you move around it, giving you an advantage over flash photographers.

Which light to buy

Actually... I'll say both. Each of them is a separate tool for its tasks and as you can see from the illustrations, I am now working on using a permanent one. Sometimes it is even possible to use both types at the same time: for example, setting a light pattern using constant light together with freezing the characters with a pulsed source on the second curtain. Another example would be shooting portraits with fashionable constant main light sources that provide comfort for the eyes of the portrait subject, while backlighting with a pulsed source.

Either way, it depends on your specific needs. Are you looking for power and portability above all else? Choose pulsed light. Do you shoot in a studio and rarely stop down to more than f/3.5? Then I will recommend a permanent one. Your specific situation may be more ambiguous, so I won't be able to give one-size-fits-all advice. However, I hope that this article will give you some general understanding of the topic and help you make the right decision.

In the world of photographers, there are often debates about what is better - a staged photo or a reportage photo, what is more important in a photograph - emotions or shooting technique. It’s not worth even mentioning the notorious debate about which is cooler than Canon or Nikon. There are thousands of opinions and arguments, but the final point is always put by those who know how to create, sometimes thanks to, sometimes despite the conditions and technical capabilities, masterpieces. And this gives direction for development to hundreds of photographers who, willingly or unwillingly, begin to imitate them.

We decided, on the one hand, to show the diversity of opinions, and on the other, to help photographers choose what they can and should focus on to achieve their goals. Our today's quick interview with famous and respected photographers about some of the nuances of shooting. We asked professional photographers to briefly answer the question: “ What light do you prefer, why?

Of course it's impulsive. Permanent has a sea of restrictions.

I work the same way with both pulsed and constant light. I prefer pulsed, because... allows you to work with closed apertures and it makes working in the studio more comfortable (the constant ones heat up the model a lot and you have to endlessly adjust the make-up). Although for some artistic designs I use constant or mixed light.

Constant, point. It is visible and it is possible to regulate the light carefully, with millimeter precision.

I use flash light more often because I have it in my studio. However, sometimes I also use constant light. If you don’t take some specialized shooting, where you need a very short shutter speed (water freezing) or, on the contrary, shooting at a long shutter speed, then I don’t see much difference in what light to use. Well, except that with constant light the pattern in the photo will be exactly the way we see it. But with digital technology this is not so critical.

Since about 2007 I have been using constant light more and more. Pulsed light left for orders. Why? I don't have any illuminator (constant light) purchased from a camera store. All lamps are either from regular stores or made by yourself.

For complex compositions, it is interesting to have a wide range of instruments, that is, a large number of light sources. Sometimes these are just flashlights (to highlight a detail or enhance a nuance), sometimes it can be a candle or a kerosene lamp.

Lamps from photo stores do not always meet my needs and it often happens that their prices are unreasonably high.

Pulse. In my opinion, it has more advantages than constant light. The main thing is that with equal energy consumption, its intensity is an order of magnitude greater than that of a constant one. And there is never too much light! Moreover, professional constant light costs much more than pulsed light, and this price is justified not by cost, but by the budgets of the cinema industry. We have to use budgetary constant sources. In general, it is impossible to say unambiguously what is worse and what is better, both types of light sources provide their advantages and have their disadvantages.

I would also like to give practical advice to novice photographers: when shooting with pulsed light, turn off ANY lighting in the studio, you will be pleasantly surprised by the picture that appears before you. Otherwise, you will have to photograph almost at random and you will never learn to control the light.

I use pulsed light: almost always. It is historically more familiar to me. And with it you can realize more creative possibilities. Although, of course, it’s easier to work with constant light, because you immediately get an accurate picture of what will be in the frame. In my opinion, we should expect a technical leap from lighting equipment manufacturers in the coming years. And, first of all, LED devices can easily occupy a worthy niche in constant studio lighting. And in price, and in brightness, and in technical characteristics.

Depending on the task. Either from my mood or from convenience. Both one and the other have both their pros and cons.

But now, as the cost of constant light begins to come down and we see more and more powerful, even spectrum, daylight-matched lighting products hitting the market, the question of the benefits of constant light is once again becoming relevant.

“Light painting”, but how much light is enough?

Perhaps you are new to lighting and want to get the most out of your money on light purchases, or at least get a brief introduction to the topic. In this article I will try to give a brief overview of the possible options and criteria for making a decision. Today we will compare the advantages of each system.