Photo tricks. Part 9.

Today again about the flash.

Photo tricks. Part 9.

Photo tricks. Part 9. Shot on I-TTL BL FP SB-900

I will explain a little how the flash works in automatic mode. Usually, automatic flash mode has a TTL prefix in its name. It stands for very simple - Through the lens - through the lens (through the lens). This means that the flash output is adjusted using the light that has passed through the lens.

This is being done quite interestingly: the flash gives a test pulse of light. Usually, the power of such a pulse is 1 \ 128 of the total flash power. The light from the flash is reflected from what we are photographing, passes through the lens and gets on the sensors of the exposure meter. The sensor transmits the light output power to the camera processor. The processor thinks for a long time, analyzes, and calculates what should be the power of the main flash pulse. The processor knows that the first pulse had a power of, say, 1 \ 128, while the exposure meter received values ​​that did not satisfy the exposure at 3 steps, because the processor makes it clear to the flash that the main pulse should be more powerful at 3 steps, and correspond to 1 \ 16 flash power. This way we get a pretty shot with the right exposure.

The most interesting: in modern central control valves, the probe pulse is practically not visible. It seems that the flash immediately gives the desired impulse of light. But this is not so, in TTL modes the pulses go very, very fast one after another in a strobe mode. The human eye and the human reaction practically do not notice the test impulse.

The test pulse is often called “preflash“. There can be many preflashes, not just one, and their intensity can be different. To be honest, I don't know how much power my Nikon flashes have. S, S. For Nikon, the delay between the test and the main pulse is of the order of 0.4 with.

With flash

With flash. TLL through an umbrella, light blur from command impulses

Important: In conventional digital cameras, the exposure metering system is not so well thought out, and the processors are not so powerful, and the flashes cannot fire a large number of “volleys” at the same time, therefore, I easily notice preflashes on ordinary digital cameras (soap dishes). Also, the test or control pulses of the built-in and external flashes of my cameras and flashes are very clearly visible when working in a creative lighting system. Nikon CLS.

When working in TTL mode, I came across a couple of interesting features:

  1. Many people have a very quick reaction, and when photographing with a flash, they begin to squint at the first impulse, and the main one "draws" them in the picture with narrowed eyes.
  2. Pre-flashes fill the background with excess light, this often gives a blur (contamination) in the eyes of people. No one needs extra reflections.
  3. The flash thus warms up faster and consumes more battery power.

To overcome this ailment, TTL just use the flash in manual flash control. With manual control, the flash output has no test fires, and the flash immediately delivers the main impulse. The beauty of this mode is that:

  1. Blinking of the eyes is completely eliminated. The momentum of my Nikon flash S has a duration from 1 \ 800 to 1 \ 40.000, during such a time not a single person will have time to blink. Yes, the person blinks, but after the flash, and the light of the flash lamp “draws” a person with open eyes on the photograph.
  2. Reduced blues in the eyes. In the studios, everyone works with flashes with manual power control, there is practically no problem of bluer in the eyes. True, there is another problem, the lighting devices themselves are often clearly visible in the eyes, often of a rectangular shape, which makes the human eyes look like the eyes of cats (not natural).
  3. Recharge lasts faster, no extra energy is wasted. Perhaps the leading number even increases, since the entire dose of light is supplied immediately.

These are the benefits of manual flash control.

Material prepared Arkady Shapoval... Look for me on Youtube | Facebook | Instagram | Twitter | Telegram.

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Comments: 58, on the topic: Photo tricks. Part 9.

  • Egor

    Great helpful article, cool pics. Thanks! I really want an external flash for photography during the day at shutter speeds shorter than 1/200.

    Hahah) P.S. smiled) But by the way, after reading the first search query “• nikon d3100 pictures give off a gray tint” - I immediately remembered this ailment when I just bought my first DSLR d3100 and for a long time could not understand what was the matter. I would not be surprised if I wrote my request in some way) However, when I overcame this ailment, I still did not understand the logical connection, how he was cured!) I will only tell you how easy it is to be treated - you just need to turn off Active in d3100 DeLighting!) Immediately the photos become more contrasting, without gray muddy shades (especially around bright areas of light), and natural, as you expect to see them after the descent) Otherwise, the d3100 is a wonderful camera, and left only positive emotions, I recommend it to everyone , you just need to disable ADL!
    ps personally, my assumption of this ailment is the incorrect work of Active DeLighting, which was included in the most budgetary DSLR for the sake of a marketing move!
    pps, frankly speaking, until now (after d3100) on my camera I avoid and am afraid to enable this function, although it already has not only “on / off”, but also influence regulation in the form of 3 levels. Maybe someone uses this function, tell us, share your experience, it will be interesting to know! Thanks in advance to everyone!

    • Arkady Shapoval

      Thank you for sharing the information. I disable ADL because it affects exposure. ADL is very rare.

    • Vladimir

      A person is often frightened by the unknown. It is worth taking time, understanding, exploring ADL with different parameters, different shooting objects, and understanding and skill will replace the fear. And there is no need to rush to reproach for incorrect work, it is more useful to figure it out. At first, I also "got" into dullness (nikon d7000), but after "debriefing" I realized that it was not ADL that was to blame, but the lazy hope that the automation would do everything for me. “I opened my eyes,” I see why a low-contrast object with a low tonal contrast should also lower the contrast by doing it. On the other hand, shots of contrasting objects with a high dynamic range ADL can not only improve, and sometimes even save. Therefore, my ADL is most often enabled for auto (in d7000 there are 5 ADL parameters), when converting nefs in the “native” converter, if necessary, ADL can be changed or disabled altogether. If disabled while shooting, ADL is not available in the converter. Converter Delighting works differently, does not always cope. If you shoot in jpg, then you really need to analyze the object, with large differences in brightness ADL will help to avoid failures. Bracketing will not be superfluous. And the reason for the dullness (in my case) is even described in the instructions: “in exposure mode M, the Auto value corresponds to the Normal value”, for low-contrast objects this is a lot.

      • Alexander Smolko

        You wrote: "when converting nefs in a" native "converter".
        Tell me, please, but what to convert to in order to process it later in Lightroom, for example? In tiff?

    • Alexander Smolko

      ABOUT! This seems to be very useful information. Tomorrow I will have to ask everyone who was in the park to return to their places in order to try to reshoot now without this function.

    • Alexander Smolko

      Is it possible to ask you to indicate where to see your work shot on the D3100. To, so to speak, through you, to believe in yourself? :)

  • R'RёS,R ° F "RёR№

    Thank you, I am reading your notes with interest. Humor is also observed in them along with useful advice, which lifts the mood. So I made a mistake (Nikon SB-700), photographing during the day on TTL and indoors “on the ceiling”? It is better to adapt and set the flash in manual mode.

    • Arkady Shapoval

      Well why, TTL is also good, it has its undeniable advantages - speed (automatic)! I use TTL a lot.

  • Lera pavlov

    After reading Yegor’s post, I wanted to write. I always take off the ADL and there are no problems with any dullness. If you want, you can look at Yandex pictures I’m there Lerochkin-valera. Basically D3100 16-85 sb-700 (TTL) sometimes 55-200.

  • MELHAUZ

    And it is possible that NL (neutral color) is enabled in the Picture Control settings, in principle, the photo will also have a gray tint.

  • rescuero

    My half, when using iTTL, eyes are always closed :) I have to use only the manual flash mode.

  • Ivan

    More є to finish the Tsikaviy regime to the ruin A, about a kind of warto zgadati. Now the regime is victorious even in the distant hour, if it wasn’t a big deal TTL and even better coped with their own zavdvnnyam. І in the mode And to sleep, how much I rosum, also dumb to sleep.

  • Max

    Don't be so “selfish” :) tell more about CANON :))

    • Arkady Shapoval

      The irony is that the owners of Canon cameras are selfish, who with great difficulty give their precious equipment for review.

  • Alexey

    PS is generally fire. :) I didn't even think that this could be asked)

    Arkady, if we are talking about strobism. Is it possible to use old proven flashes (not the ones that are charged from the network :)) for film cameras with a central locking system? Which ones do not exactly burn the camera. If there is information, share :)

    • Arkady Shapoval

      I do not own information on old outbreaks.

    • ALX

      As an option. Sinhrik will not burn. And raise the level of artistry of the photo. Worth trying!

      • Meticulous Reader

        Synchronizers are different ...

    • Meticulous Reader

      Do not directly connect to the camera. It can be used with synchronizers if they support high-voltage devices.

  • Kostya

    Tagging a little scho if I photograph my sister in TTL, then in some closed eyes, I go to M.

  • Igor

    Well, again, the robot’s widow has been described to be offended by the TTL BL mode, but already not TTL.

    • Igor

      I take my words back, after reading with respect, I’m sure that the robot is able to understand both modes of writing TT TTL BL TTL BL

      Ale hot_v bi specify those m_sce for the reason of a trochy, who got it wrong:
      “This is done quite interestingly: the flash gives a test pulse of light. Usually, the power of such a pulse is 1 \ 128 of the full power of the flash. The light from the flash bounces off what we are photographing, passes through the lens and hits the meter's sensors. The sensor transmits the value of the light output to the camera processor. The processor thinks for a long time, analyzes, and calculates what should be the power of the main flash pulse .. ... "

      - due to the help of a trial pulse, get back to the object.

    • Arkady Shapoval

      Read carefully again, and you will see that everything is exactly as it is written.

  • Ayrat

    In the title of the article, the prince hurts the eye a little))
    The article is great, thanks.

    • Arkady Shapoval

      Thanks. Corrected.

      • NKM

        To overcome this ailment, TTL is enough to use the flash in the manual flash control mode.
        Execute cannot be pardoned.
        It seems to me that the comma before TTL distorts the meaning of the sentence.

  • Beginner

    Please tell me, in TTL mode, the shutter speed is shorter than 1/250 is not set. What is the problem ?

  • Beginner

    Sorry, in my bundle of d7000 + sb700 this is not possible, or I'm very beginner, thanks for understanding.

    • Arkady Shapoval

      Perhaps enable FP mode (Auto FP

  • M.

    After all, there is a mode of preliminary exposure metering, it can be put on a programmable button (how exactly it differs from model to model, is in the instructions). After clicking on it, there will be one preview with metering, which the camera will remember.
    Until shooting conditions change, you can shoot, the impulse will always be of the same strength. If the conditions have changed, we poke the same button again and forward further ... Much faster and more convenient than shooting in manual mode.

  • Dmitriy

    Hello, Arkady.
    I'd love to see a review of the nissin di700 canon.

  • Alexander

    Hello guys, can you advise how to synchronize the FalconEyes SS-110B studio flash with Nikon d 90 using the built-in flash? I take a picture in M ​​mode, turn on the flash at minimum power, the studio works, but apparently all the same earlier, since the photos are dark. So there is still a "pre-flash"? How to remove it, tell me, it is very necessary ...)

  • Twilight_Sun

    Thanks, good article.
    It became interesting how the built-in flash works, I conducted an experiment: I shot it at 120 frames per second and slowed it down 10 times (i.e., up to 12 fps). It turned out such a disgusting quality but understandable video http://youtu.be/CCq1A33DePM.
    For verification, I set a high ISO and -3 stop correction for the flash itself, as a result, the preliminary impulse, judging by the video, is even stronger than what was issued for the actual shooting. Could this be, or is it an illusion?
    Is there any way to understand the power of the pre-pulse (1/128 or more)?

    • Arkady Shapoval

      This may not be an illusion. The power of the test pulse can only be set on some external flashes.

      • Twilight_Sun

        Clear. If this is not an illusion, then it turns out that the flash first beats to the full and blinds people even when it is not necessary according to the measurement result. This is generally not good.

        • Arkady Shapoval

          It is triggered by a test pulse not at full power, I assume that 1/32 of the power is used.

  • Anatoly

    Arkady thank you. The question is why the sb-700 in the remote su-4 mode is in manual mode and shoots serially and evenly without failures, but you only switch to auto mode so the series does not stand a couple of frames and the mother jumps in power. And in general it is not clear if the flash works in dir.su-4 what kind of car can we talk about? After all, the puff is not in creative lighting mode. Nikon d5100 camera.

  • Dima

    Good day, tell me please, Nikon D7100 carcass, sb-910 lens, without testing preliminary flashes, except in automatic mode, it doesn’t take pictures at all! Tell me what is the trouble? And with the priority of the aperture and the priority of shutter speed, and on the flash of which I just did not remake, I was so tired.
    I have kids, while you catch the shot, and these testing preliminary flashes spoil everything, the kids turn away from them and that's it!

    • Arkady Shapoval

      turn off the red-eye mode on the d7100.

      • Dima

        Well, thank you! Helped out, I'll go try, tomorrow I will unsubscribe. Good luck, luck and excitement to you! Well, interesting shots.

        • Alexey

          I’m just learning myself, but I would be ashamed to ask such a thing, is it really impossible to read the instructions a couple of times?

  • Eugene

    So as not to write a thousand times, I'll write everything in one message ... there is a question about the sb900, what is the puff speed in the flash ?, and what do the parameters in the puff 1 \ 128 menu mean, I noticed such a nuance in working with the synchronizer, I don't understand this flash manages to charge, or is it too short a puff pulse (namely menu 1 \ 128) which was mentioned above (and the shutter is triggered with some kind of puff difference) the frame is not always exposed from the first frame as it should - I take the first frame or as if it is not lit at all , or it is dimly lit, and on rare occasions the puff is too much straight, everything floods, unreal overexposure and the smell from a flash of burnt plastic - but this is most likely a problem in the synchronizer, or the processor, this is a specific question, why not every frame is exposed as needed, how you can fight this) yongnuo 622N Synchronizer

  • Sergei

    Huge to you Arkady, thanks for the article! And in general you have interesting and intelligible "stories"! ;-) Especially in comparison with other sites where everything is somehow clever and “dull”! :-)
    Well, having read specifically this article, I decided to buy a flash without TTL with a calm soul! All the same, it would often have to be turned off, and so I can take it three times cheaper !!! Thanks again!!!

  • R'RёS,R ° F "RёR№

    Arkady tell me how to take the last shot?
    What are the settings….
    I understand this in manual mode?
    Thank you!

  • anonym

    “Recharging lasts faster, no extra energy wasted”

    correct

  • Benjamin

    Good afternoon, Arkady!
    As you know, the built-in flash Nikon D5100 (as well as some other Nikon DSLRs) cannot be used as a master.
    Is it possible to use a universal light synchronizer, for example, type SF-565, to set this flash, which is in TTL mode, to ignite an external flash, say, YN8EX TTL?

    • Vladimir

      In such a synchronizer there are no contacts for TTL operation.

  • Benjamin

    Thank you.
    I understood your answer so that this synchronizer provides the flash only in manual mode.
    And which of the Nikon's hot shoe pins provides TTL flash?

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