Flash —
a device that allows you to briefly illuminate a scene while it is being photographed.
Previously, photographers set fire to magnesium powder for this purpose, then electronic flashes with powerful flash lamps appeared.
Flash power
The flash power is determined by its guide number. For example, a guide number of 10 indicates that the flash produces enough light to adequately (that is, not too brightly or too dimly) illuminate a subject 10 meters away. It does not take into account which camera and lens the photo will be taken. —
It is believed that the lens is “ideal”, but in practice any lens blocks light (corresponding to its aperture) and therefore you will need to either increase the flash power or reduce the distance. The light from the flash is scattered over the entire area of the frame, so the dependence of illumination on distance is not linear, but quadratic. Simply put, if we move 2 times further away, the scene will turn out not 2, but 4 times darker.
Thus, the real distance from which an object can be illuminated normally is calculated based on the guide number of the flash, adjusted for the characteristics of the lens and camera sensitivity.
Built-in and external flashes
They have built-in flashes large quantity cameras These are small and weak flashes, with a small guide number, which allow you to photograph from 2-3 meters. There are cameras with fixed and pop-up built-in flashes. The advantage of pop-up flashes is that they are further away from the lens when working than stationary flashes. This reduces the likelihood of red-eye appearing in the photo. Red eye occurs when direct flash light is reflected from the fundus of the eye. The further the flash is from the lens axis, the less likely it is that light reflected from the fundus will return to the lens.
In addition, on some cameras the lens can extend very far and block the light from a nearby flash. As a result, a black shadow will appear on the bottom or edge of the photo. Rising flares help combat this problem as well.
External flashes —
These are separate devices, with their own power source, powerful and multifunctional. They are called "hammers" and their guide number can reach 50. They are installed on the top of the camera through a special connector called a "hot shoe". If the camera has a hot shoe, then you can install an external flash on it, otherwise you cannot. The same flash can be used on different cameras, since the hot shoe is quite universal. But the functionality of the flash may not be complete.
External flashes also have a rotating head —
that is, the light beam can be directed in any direction: up, sideways or even back from the object. This allows you to work not with direct, but with reflected (from a wall or ceiling) light, creating softer lighting.
In addition, the external flash head may have a zoom —
that is, for different viewing angles of the lens, the corresponding flash illumination angles can be adjusted. This allows light energy to be spent more efficiently. The head zooms either manually or automatically when the lens zoom changes.
There are also professional studio flashes —
These are even more powerful and very precisely working devices that are not placed on the camera, but are controlled from it via a cable or light/radio signal. They are used mainly in studios to create precise lighting patterns. Several flashes can be used simultaneously, placed in different places in the studio.
"Dumb" and "smart" flashes
Dumb flashes include older external flashes and many studio flashes. Their stupidity lies in the fact that they are only capable of producing a light pulse based on a signal from the camera, and nothing more. When shooting with dull flash, you have to make calculations using the flash guide number, the distance to the subject, and the lens aperture to get the right light intensity. Many stupid external flashes have a distance and aperture table on the back wall. —
to make calculations easier. When using flash heads with a rotating head —
for example, when directing light towards the ceiling —
You have to additionally take into account the distance to the ceiling, the distance from the ceiling, the reflectivity of the ceiling and the dispersion of light.
Studio flashes are stupid due to the fact that they are not required to do anything other than execute the settings precisely specified by the photographer.
Smart flashes —
These are modern built-in flashes (not counting completely rubbish disposable cameras), and modern external flashes.
Usually the name of a smart flash contains the abbreviation TTL (Through The Lens, “through the lens”). This means that the flash itself is able to determine how much light it needs to produce for the scene, and there is no need to calculate anything. The smart flash communicates with the camera through additional contacts in the hot shoe. Each photo manufacturer has its own protocol for this communication and differs in available capabilities. Therefore, a smart flash will only be smart on those cameras for which it is intended, and on all other cameras it will be dumb. A smart flash works like this: the flash emits a test light pulse, after which the flash itself or the camera measures the reflected light and considers what happened —
too dark or too light (measures the light entering the lens or a special flash receiver, hence the name TTL). Communicating with each other, the camera and the flash find the required strength of the light pulse and the flash emits a second light pulse, this time the one needed. At this moment the shot is taken. Two impulses follow each other so quickly that a person does not notice it and believes that there was one impulse. However, during the first impulse, some people manage to start blinking, so the photographs appear with half-closed eyes.
Smart flashes also understand when the head is pointed to the side or at the ceiling and make adjustments accordingly.
However, even TTL flashes are not always able to produce consistently good results in all conditions. —
the technique is not perfect. Therefore, if something doesn’t work out, the flash is used as a dull flash, with manual settings.
Flash Sync
Often the photographer's task is to create the desired light pattern, the balance of light and shadow. You can use multiple flashes for this. This mainly applies to studio flashes, but regular external flashes can also be used.
Let's say we have three flashes set up in the studio, each of them aimed in such a way as to embody our idea. When we take a shot, all three need to fire at the same time. Synchronization is used for this. The simplest and most ancient method of synchronization —
This is the sync cable that goes from the camera to the flash. More modern methods
—
This is light and radio synchronization. A transmitter is placed on the camera's hot shoe that emits light or radio waves, and flashes must have built-in receivers. If they are not there, no problem. —
Receivers can be purchased separately and attached to flashes, again via a hot shoe connector.
The advantage of flash sync is that you can use any other flash to trigger. But a problem often arises when they try to synchronize external flashes using light from the built-in one. The flashes fire, but the pictures come out dark. This is because the built-in flash —
smart, and therefore makes two impulses. External flashes fire from the first evaluative pulse, when the picture has not yet been taken. To combat this problem, light detectors with retardation are used. —
they miss the first impulse. But The best decision
—
use a dull flash as a trigger.
You can also sync two or more smart flashes from the same model range, if one of them is installed on the camera. The one on the camera is designated as the leader, and the rest —
slaves. In this case, they can remain smart, since they negotiate with themselves, and the possibilities of working with them depend only on the model.
Other flash options
As a rule, only one thing is required from dumb and smart flashes —
illuminate the stage. However, more expensive models may be equipped with additional functions.
Red-eye protection
As you know, red eyes are caused by light reflecting from the fundus of the eye. He gets there because the pupil is dilated —
after all, if a flash is used, then it happens in relative darkness, and in the dark the pupils dilate to let in more light (pupil —
diaphragm of the eye!). Therefore, to eliminate red eyes, you need to make your pupils small. To do this, the flash fires several rapid bursts before the photo is taken. Those who see these impulses have their eye pupils sharply constricted by the bright light. Immediately after this, a photo is taken, and thus the red-eye effect is reduced. However, the best way to combat red eye is to use diffused rather than direct light. —
for example, by pointing the flash at the ceiling.
Strobe
Strobe mode allows the flash to fire multiple flashes during one shot. The number and frequency of pulses can be adjusted. This allows you to capture different phases of an object’s movement in one frame. —
for example, the swing of a pendulum or the jump of an animal. Since the entire frame will be illuminated several times, it is advisable that the subject being photographed be noticeably lighter than the background, otherwise nothing will be visible.
Modeling light
The flash fires a burst of very short pulses, simulating constant light. This allows you to see how the lighting will turn out, where and what the shadows will be, etc.
Sync with other flashes
This function may be built-in, but if it is missing, you can purchase a synchronizer separately.
Synchronization on the first or second curtain
Where does the name come from: the design of the camera shutter is a curtain that opens and closes (there are other designs, but we won’t touch them for now). In the most classic case, there are two curtains. The first curtain opens the frame, after a while the second curtain closes it. Therefore, the flash can fire when the camera shutter has just opened (on the first curtain), or just before it closes (on the second curtain).
When shooting still scenes, this does not matter, the result will be the same. But if, for example, we film a moving car at night, we will get the following results:
By the first curtain —
the flash illuminates the car immediately, then it drives for a while. Since the scene is dark, without flash, only the headlights will be visible. If a car is moving, the light from its headlights will merge into a line. In the photo we will see a car (lit by flash), and the lines of the headlight marks will be located in front of it.
On the second curtain —
First, the car is filmed in motion, and then the flash fires just before the shutter closes. We will see the car again (but not in the initial, but in the final position of movement), and the lines of traces from the headlights will be located behind it.
High-speed sync mode
The flash pulse is usually very short —
is measured in thousandths of a second, but generally cannot be used at shutter speeds above 1/250 of a second. However, the camera has shutter speeds of 1/1000, 1/4000 and even 1/8000 seconds. Why can't you use flash at these speeds? What's the matter?
If we look again at the camera's curtain shutter (and this limitation applies specifically to it), we will find that the frame opens completely only at a speed of 1/200 of a second and below (it varies for different cameras; the average value is indicated). That is, the first curtain opens the frame, 1/200 of a second passes, then the second curtain closes the frame. What happens when the shutter speed is higher than 1/200? The curtains do not move faster, but simply do not open completely. As soon as the first curtain begins to open the frame, the second immediately begins to close it, moving after the first. The difference between the start of the first and second curtains is the conditionally required 1/1000 of a second. A gap of a certain width is formed between the curtains, which moves along with the curtains from one edge of the frame to the other, revealing successively individual pieces of the frame. It turns out that each piece opens exactly for the conditionally required 1/1000 sec. It is clear from this that when the flash fires a pulse, it occurs only at one position of the slit, while the rest of the frame is closed.
Therefore, in order for the flash to illuminate the entire frame, the minimum possible shutter speed is used, at which it opens completely —
that is, on average 1/200 sec.
High-speed sync mode allows flashes to emit a very long pulse, which is enough to illuminate the frame from beginning to end while it passes through the slit. This makes it possible to use the flash at any shutter speed. However, such long pulses have a reduced power, since much more energy is consumed.
Autofocus illuminator
When shooting in low-light conditions, the camera's autofocus system struggles because its sensor is unable to determine focus in the dark. An external flash may have a backlight function to make the sensor easier to operate. Illumination can be produced either by the main flash lamp or by an additional one designed specifically for this purpose.
Slow flash sync is available on a wide range of digital cameras. What is special about this synchronization mode? Slow flash sync allows you to take long shutter speed photos and shoot with flash. When using slow sync, the camera receives more light information environment, both in the background and in the foreground. As a result, the flash will be powerful enough to maintain the correct temperature of the surrounding light. Many digital cameras allow you to set slow flash sync manually, on compact cameras This mode works automatically, and it is disguised under the names “night mode” or “party mode”. If you have never experimented with these modes, be sure to give it a try; you will definitely be pleased with the results.
How does slow flash sync work?
Slow sync flash lets you choose the sync speed, flash output, and flash duration. When using slow sync, the shutter stays open much longer to large quantity light entered the frame. This means that the main subject should remain as still as possible; if it moves even a little, its edges will be soft. The flash fires at a specific point during a longer shutter speed, and the flash duration is much shorter than the shutter speed in "standard" flash mode. In this case, you can use a smaller aperture to achieve greater sharpness in the final image.
When to use slow flash sync?
It is recommended to use slow flash sync in low light conditions, when you feel that a regular flash will not be able to guarantee you a beautiful result. Slow sync flash can also be used when photographing sporting events. Due to the slow shutter speed associated with slow flash sync, you need to stabilize your camera to avoid shake. You'll probably need a tripod, and consider purchasing a cable release or remote release tomorrow.
What are rear and front curtains?
When you set your camera to slow flash sync mode, you'll likely be able to choose between front-curtain and rear-curtain sync. In this case, you have the opportunity to configure the camera so that the flash fires at a certain moment. With front curtain sync, the flash will fire as soon as the curtain opens - at the beginning of the shutter speed. Rear-curtain sync means the flash will fire at the end of the shutter speed, before the rear curtain closes. Depends on the choice of synchronization final result your image. Rear-curtain sync tends to produce little motion blur, keeping the main subject sharp, while pictures taken with front-curtain flash will be brighter and lack the naturalness of ambient light. The ability to synchronize using one or another curtain gives you the opportunity to experiment and come up with more and more original shots.
Conclusion
Slow flash sync gives you creative options when shooting at night or indoors, and is a great way to avoid the mundane and unremarkable photos that often result from using standard flash. automatic mode flashes. Slow flash sync expands the boundaries of flash photography, allowing you to capture movement (in the form of motion blur) that is typically missing from traditional flash photography. Plus, you get the ability to control background lighting without sacrificing depth of field.
Thanks to second-curtain flash synchronization, you can create beautiful trails from the movement of your subjects, which will give the photo greater dynamism and fill it with energy.
This may seem difficult and will require practice on your part. Only by practicing will you get desired result. Typically, the speed of light from a flash is much faster than the camera's shutter speed, the Nikon SB900 has a flash speed of 1/880 sec. at full power.
If the camera shutter speed is set to 1/60 sec., and you are also using the flash, then to the naked eye it will appear that the shutter and flash are firing simultaneously.
Image by Mehmet Salih Güler / IStock
Extend the movement
Default for most digital SLR cameras it states that the flash fires at the beginning of the exposure, and in most cases this produces excellent results.
However, if you find yourself in a shooting situation where you have to use a slow shutter speed, such as 0.5 sec, you will begin to notice an unusual effect from your flash.
If the subject is moving - be it a dancer on the dance floor or a fast-moving cyclist - and you want to combine a long shutter speed with flash, you will notice that when the flash fires at the beginning of the exposure, it will freeze the subject, and subsequent movement will not be visible for the remainder of the exposure time. camera.
How to fix this? Set the flash to fire at the end of a long shutter speed. As a result, the shutter speed will work and shoot the subject throughout this entire time, and only before the second curtain is triggered will the flash illuminate your subject. This way you will get both a dynamic shot and good lighting.
By practicing shooting with second-curtain flash, you will gradually begin to shoot better, and soon you will definitely like your results.
Improve your technique
Take a portrait using a slow shutter speed and second-curtain flash. As a result, you should get a sharp shot of your subject, but also get some interesting motion blur in the area that was out of focus.
Set your shutter speed to slow with flash, set your camera to rear (or second) curtain sync, and photograph some action. It is best to try to master this technique in free time, and not try to create a successful shot already on the spot, when it is very important to get a good result on the first try.
So... what's the best way to use flash? What features of flash photography exist today? What are the secrets of shooting with built-in or external flash? Do you need additional accessories for flash? What mistakes can you make when using “blitz” (another name for flash)?
When is the flash used? Not only in the dark! It happens that its use is necessary in backlight (when shooting against the sun) or if it is necessary to eliminate too saturated, deep shadows in too “hard” light.
First, let's look at using flash built into the camera. On some cameras, the flash must be opened and turned on before use... This is done either with your fingers or using the button located next to the flash. For example, on Canon DSLRs, a button next to the button is used for this, but on other cameras it may be different.
Flash operating modes. Settings, Their Selection and Use.
Many cameras have a built-in flash, There are several flash modes. And some other settings...
For example, you can adjust the flash power. If the objects in the photo are too bright, you can reduce the flash power. Its power is often adjusted separately from the overall exposure...
Another important setting: shutter speed when using the built-in flash. The fact is that using the built-in flash, you cannot use a shutter speed less than (shorter) than 1/200 or 1/250 of a second! Such are the technical limitations. And often the camera’s automation selects a very long shutter speed, so that the image is blurred when shooting. To prevent this from happening, many cameras have a function that allows you to fix the shutter speed at just 1/200 (or so), or leave the automation to work, but do not allow a shutter speed of more than 1/60 of a second (or so). But keep in mind that with these settings, the background of the photos may appear too dark in the photo, because a short shutter speed is not always enough to expose a dark night background. To minimize this effect, you should open (“increase”) the aperture as much as possible (for example, to a value of 3.5) and increase the sensitivity of the matrix (for example, set ISO 1600), although the effectiveness of such movements is often almost not felt :(
Keep in mind that when shooting with flash, the background may be too dark.
Synchronization on the first and second curtain (with long exposures)
In the majority SLR cameras you can choose whether your flash will flash at the moment the shutter is released, or at the end of the exposure (i.e. if the shutter speed is 3 seconds, the flash will fire 3 seconds after pressing the shutter button). This matters if you use a slow shutter speed (longer than a second). The first option is most often used (“by the first curtain”), because otherwise, it will be difficult for you to guess at what moment the flash will occur... Photos taken when synchronizing with the second curtain turn out prettier, although they are more difficult to take IMHO :)
Manual mode of the built-in flash(not available on all cameras) can be useful if you want to achieve the effect of sparkle in the eyes (reflection of the flash in the eyes) or to suppress too hard shadows (for example, if you are photographing on a cloudless sunny day), then with a flash set to low power you can use during the day. But using manual mode requires a certain skill and experience. However, isn’t it time to gain this experience? ;)
I could also write about the flash mode with red-eye protection... but the main thing about it is to know that it exists and be able to activate it on your camera
Disadvantages of the built-in flash It can be attributed to the fact that it is small in size, and light from small sources most often turns out to be “hard”, giving deep shadows and not very beautiful highlights on the skin and very “hard” shadows behind the back of the subject! Keep this in mind when shooting with flash, no matter where you take pictures - outdoors or indoors, this is important! Sometimes, to get rid of glare, a fashion model can be asked to wipe the skin with a handkerchief to dry it, or use more powder in makeup.
Even external flashes “suffer” from the fact that their light produces too strong glare on human skin and too rough shadows behind the backs of fashion models. To eliminate these image defects (which, by the way, are extremely difficult to correct even in Photoshop), we use light diffusers that fit onto the flash. But they are mainly intended for external flashes, and not for built-in flashes, especially not for those built into a compact camera. If you have not yet chosen or purchased an external flash, then you can use a sheet of paper that is not too thick and can be held close to the flash as a diffuser. Or cut and put a ping pong ball on the flash. There are other ways to make a diffuser for a built-in flash with your own hands, but this is the topic of a separate article...
Working with an external flash
What is the difference between an external flash and a built-in flash? First of all, size and power. The second difference is that most external flashes can “flash” not only “in the forehead” of the model, but also turn in other directions, so that shooting in reflected light becomes possible - which is simply necessary, for example, for wedding photography.
Bounced flash light
You can point the flash, for example, at the ceiling - then its light reflected from the ceiling will seem natural (similar to the light falling from the sky during the day) and will not produce strong glare on the skin.
Flash working head-on (on the left), and using reflected light (on the right).
Here the lines schematically represent the path of light rays.
Or you can point the flash at the wall - on the side of the model. Then in the picture we will get lighting coming from the side (light reflected by the wall), which can be mistaken for light from a window or the like. Sometimes reflected light works wonders, and a single flash on the camera gives an effect that is not always easy to achieve even in a photo studio!
During the shooting, only one flash was used; it was on the camera, but due to the fact that it was directed past the model, towards the reflector, its light fell on the model from the side and even slightly from behind.
Photographer: Karpin Anton. ©
External flashes also have more creative modes and other settings than their built-in “colleagues”. For example, stroboscopic mode is almost never found in flashes built into the camera.
Strobe flash mode(or “multiple flash mode” on Nikon).
With a long exposure (more than a second), it allows you to get several translucent images of objects moving quickly in the frame. It is most impressive if these objects reflect light well and move against a dark background. When shooting in this mode, I recommend using a tripod.
Some rights reserved by Stefanotshcki!
Exposure - 2 seconds. This is what the “stroboscopic” effect looks like.
An external flash allows you to control your power much more flexibly and quickly.
Flash synchronization at fast shutter speeds.
As mentioned above, the built-in flash does not always make it possible to use it at a shutter speed shorter than 1/200 or 1/250 seconds (or even more serious limitations). But most external flashes have a synchronization mode at low shutter speeds, which is extremely important in sunny weather, for suppressing too hard shadows on the faces of fashion models, and for adding shine to their eyes.
The use of several flashes will open up especially wide creative prospects: one master (on the camera) and several slaves. Then, even outdoors, you can create photographs with almost the same convenience and control over light as in the studio.
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