If you like sports photography, high-speed photography, and night photography, then do not miss this article on the stroboscopic flash photo. With a strobe light or a high-frequency flash, you can immortalize in a single take a sequence of moving elements, for a visually compelling image that will surprise more than one. And all this with some standard accessories and resources that any photography lover can have at home.
What is a stroboscopic flash photo?
A photo with this type of lighting is especially indicated to integrate into a single shot a complete sequence of moving elements.
This is like triggering a runner on a runner, for example, and then assembling the series in a single image with the digital edition. Still, instead of “cheating with the computer,” we exploit the magic of light.
How to take a strobe photo
Imagine that you are in a room or place in total darkness, all objects that do not emit or reflect light will remain completely dark, regardless of the duration of exposure of the capture. And if an object moves, it will not appear on the image if it does not produce or reflect light.
But what happens if, at a given moment, we light a lamp and light an object? At this point, the subject begins to be “recorded” or printed on the capture. If the object moves and the light remains lit for a long time, the silhouette will appear blurred; it will take on a fiery appearance. But if the light is a flash of high-frequency flash that stays on at speeds around 1 / 10,000, the movement will remain frozen entirely.
Also, if between two flashes of flash in the complete darkness, the object changes position, the moving element will not be captured. They will be obtained as soon as it is triggered again in the next position, which gives, with relatively long exposure time, a complete sequence of the captured subject’s movement without the latter appearing hazy but immortalized with all its successive intermediate positions.
Case study: differences between a stroboscopic photo and light painting
Observe the difference between the objects that appear in the next image. I’m on the left, I’m wearing a blue cap, and I’m throwing a glowing yellow ball to my friend Marga. In contrast to the image, Marga launches me, in turn, a small LED light on.
My camera is mounted on the tripod; it takes only one picture at the exposure of one second to f / 4 ISO 100. Installed on the camera, the flash is set to emit not a single glow but a burst of high-frequency lights. Correctly, the photo is configured so that the flash emits nine flashes during the full second that the exposure lasts.
If you observe the image, the lamp that emits its light leaves a trail in the picture. This parabolic drag is continuous and would remain captured, regardless of how the flash works. Indeed, it has its light that strikes the sensor. But if you look at the ball I throw, it also leaves a parabolic wake but intermittent, not continuous. This is explained by the fact that when the flash launches the lightning, it immortalizes the ball in the position where it is. We will see the shot in as many positions as lightning flashes produced. If the flame had not worked, the bullet would not have been captured at any time.
On the picture below, we did not throw the lamp, just the ball. The exposure is the same as on the previous test, 1 second of capture, but the flash is now configured to perform 16 triggers, so the separation between the light spots left by the ball is less important.
For perfect photos, models should be photographed on a cyclorama (a continuous background that extends as far as the ground), black in color, to avoid unwanted light reflections. It is usually the big studios that have this type of space. But instead, and especially if you want to take pictures of the whole body of people in motion, you will have to look for open, dimly lit spaces without too many objects that may reflect the light of the flash or produce their light.
The following photos were taken at the beach, and in a gymnasium and both places, I was not able to eliminate the parasitic lights. But that does not detract from the spectacular side of the images.
Essential accessories for strobe photography
The following items are needed to take pictures with a strobe light:
- Flash: with the trigger option in high frequency or strobe. For all shots, I used a flash Gloxy GX-F1000, whose beautiful features are suitable for this type of shot but also in any circumstance. Besides, it communicates perfectly with my camera, and I can use it in slave or master mode with other slave flashes on my device without transceivers.
- Tripod: to install the unit so that it stays stable.
- Camera: As always, any device that can be set manually.
Other recommended elements
- Remote shutter or flash sync cable: it will move the flash so that the light emits in the desired direction and to be able to move closer or apart the model to be photographed
- Trigger cable or remote control for the camera: to avoid touching the camera when triggering and thus avoid vibrations.
An alternative that might interest you for its ease of use and practicality is the Maps trigger. It serves as a trigger for your device and your flash cobra, and you can activate both of your smartphones, thanks to the app Maps. It has three sensors: light, sound, and laser. It is so practical that you can easily make professional and vibration-free photos.
Factors that influence strobe photography
A strobe flash can be configured to send a series of quick trips, instead of a flash at the configured power. Of course, the power of multiple lightning will never be comparable to that of an individual trigger at maximum power, so the more the number of electricity or the trigger frequency, the more the strength will decrease.
Strobe flash configuration features
In strobe mode, a flash has three configuration settings:
Number of triggers
It is an integer that refers to the number of times the flash flashes. If you want it to launch five flashes, for example (regardless of speed and power), you must choose the number 5.
As a fraction (1/4, 1/8, 1/16, 1/32, 1/64, 1/128), it indicates the power of lightning, knowing that 1/4 is the maximum power and 1/128 the minimum power. You can not configure higher power for flash charging times and to prevent overheating.
Frequency refers to the speed of lightning and is measured in Hertz (Hz). When we say that a system has a rate of 1 Hz, it means that it operates once a second. My flash can be set between 1 and 100 Hz. In other words, it could fire at a speed of 100 triggers per second. Which does not mean that it launches 100 triggers, but at speed, it will launch?
To find an equivalence easy to understand, it’s as if you drive 5 km at a speed of 60 km / h or travel at 120 km / h. The kilometers (the numbers of trips) are the same in one case as in the other but not the speed at which one circulates. Here, the triggering power could correspond to the load that the vehicle supports. A big load would be 1/4 or 1/8, while traveling without a load would be 1/64 or 1/128. Obviously, the less the load will be substantial, the faster we can go or more we can do kilometers and investment.
Strobe flash configuration
To configure in stroboscopic mode, the Gloxy GX-F1000 flash used for all the photos of this report; one must take into account the following elements.
- Indicates the power of the flash ‘s flash.
- Indicates the number of repetitions or flashes.
- Mode button to set the flash in TTL, manual, strobe, or slave mode.
- Configuration wheel of the different values.
- Button for selecting the parameters to configure.
- Button on-off (long press) and LCD illumination (short press).
- Button to set the flash zoom (automatic or select the corresponding zoom).
- Indicates the zoom on the camera
- Indicates the rate of the lightning trigger in Hz
Magento SKU = “GloxyGX-F1000Flash”]
It must be taken into account that the respective configurations of the different parameters are strictly related to one another so that some of them will be impossible to select because it is the very programming of the flash that prevents you from doing so. You can not go beyond the maximum triggering power, for example. So, if I try to configure six triggers at 1/4 power, the sum of the six would be 1/4 + 1/4 + 1/4 + 1/4 + 1/4 + 1/4 = 1.5, in other words, this goes beyond the limits of the equipment.
If you want to trigger very fast triggers, you cannot configure triggers at high powers because the device does not give the flash time to “recover,” and it can even “burn.” To avoid this, the flash itself prevents you from selecting these trigger options in its program.
If you look carefully at the two test photos above, the face of my friend Marga is perfectly lit on the first, while it turns out a little underexposed on the second because the flash could not be configured at higher power (between 1/32 and 1/128). Between “different Marga” on one as on the other photo, there is more space in the first picture because the trigger speed is much lower than the second (between 5 and 20 Hz). Also, on this second photo, I had to tell the flash to throw more lightning when I wanted to capture a more extensive sequence and increase the exposure time to 3.2 seconds.
Calculating the exposure time on the camera
Another interesting question is that the exposure times of the photo should never be lower than what is set in the flash configuration. For example, if I want to take a picture at the exposure time of 1 second and configure the strobe flash to give me four triggers at 3 Hz, the last trigger will remain “outside the exposure.” By pressing the release button, the 1-second exposure will start at the same time as 3 Hz flashes. In other words, it will fire three flashes per second. After this time, he will finish the capture, but he will have one last trigger to launch, which will be outside the exhibition.
There is a general rule that states that:
The exposure time must be> = (Number of trips / Speed in Hz)
In the photo below, for example, the black karate belt Manuel Gómez took about two seconds to complete its movement (that’s good because it was asked. Otherwise, it would have been much faster). So I could apply the formula above and set the approximate number of triggers, I wanted the maximum amount, just like the speed in Hz. The power was determined semi-automatically by the flash because it prevented choose high skills; only the weakest were available.
The camera is configured with an exposure time of 2 seconds (at f / 4 ISO 100), while the flash is set at 14 fires of 7 Hz, after applying the mathematical formula seen previously.
For the next photo of the jump, it was decided to separate more “karatekas” and to avoid the superposition of images so that silhouettes more distinct from each other on the sequence, to highlight the mechanics of the jump.
As for the previous case, the device was configured with an exposure time of 2 seconds (at f / 4 ISO 100) but in this case, as we wanted to separate the silhouettes, we said, we had to lower the speed in Hz and the number of triggers in half to respect the mathematical formula. The configuration was, therefore, seven trips at 3 Hz.
Other factors to consider
For subjects perfectly defined on these shots, we must work with a black background and in total darkness, if possible, so that the only source of light comes from strobe flash.
We do not appreciate the trajectory of the ball, in this picture of the foosball, for example, because the game track reflects so much light that it ends up absorbing the movement of the ball.
Flash incidence angle
The picture above was taken with the front flash on the camera. With this configuration, the painting and the bricks of the wall stood out too much from the rest. So we decided to change the angle of incidence to 45 degrees so that the back “tail” of the lightning bolts are out of the frame, and they do not light the bottom. This allowed us not to highlight as much as we wanted, these harmful elements in the photos.
To separate the flash from the camera, we used a wireless remote shutter, with which we could place it in the desired position.
The distance of subjects from flash
Apart from the configuration of the flash output, the distance between the subjects of the photo and the lighting source must be taken into account: the famous lighting rule by which the intensity of the light varies inversely proportionally. Squared the distance between the light source and the subject. This will allow us to change the lighting in the photos just by changing the distance of the light from the subject.
Another way to control the light beam emitted by the flash is to adjust the zoom of the flame. If you want a narrower beam, which lights more concentrated, like the projector of a theater or a circus, you have to adjust the zoom of the flash on the maximum, even if you have a big goal angle. If, on the contrary, we want the light beam to encompass the entire movement of the subject, we must adjust the zoom of the flash on its position at the widest angle, and we will be able to light the entire frame of the photo and make it more punctual.
On this last take where we appear, my friend and I, we used a snoot (a kind of visor or conical concentrator of light to change the lightning flashpoint light), homemade, to prevent light leaks to the floor. Thanks to this accessory, we have obtained a background almost entirely black, except small reflections at the edge of the beach.
For this picture, as we can see, the number 12 was set at 12 Hz with a flash zoom set to maximum, i.e., 180 mm and 1-second exposure (f / 4 ISO 100). At the same time, we made a snoot by hand with a backpack separator, sufficient enough to prevent lighting of the sand that was under our feet.
The factors that affect the final image obtained are numerous, and experimentation remains the best way to produce the best results. I invite you all to take pictures with a strobe flash, and you will see that you will make spectacular shots in the blink of an eye, even more than those presented here. And you have them, we encourage you to share them on our social networks but also to ask all your questions below, without comments.