Understanding Flash Duration

Want to freeze movement? Flash duration is key.

Flash duration varies greatly between different types of studio lighting. If you’re looking to freeze movement, it’s important to understand its effects.

Here, Karl Taylor explains exactly what flash duration is and the impact it can have on your shot. In a step-by-step demonstration, he shows different studio lights with different flash durations and their ability to freeze movement.

In this class:

  • Why flash duration is important
  • What impact flash duration has
  • When to use fast flash duration
  • Measuring flash duration
  • Practical demonstrations of different flash durations
  • Sync speed vs flash duration

Questions? Please post them in the comments section below.

Comments

  1. Hi Karl, supposing I’ve got a flash with a large flash duration but that has a high speed sync mode feature. Up to what extend could I reach the same results of a short flash duration shoot? Is the cut of light power the only problem in that case, as I would kind of use just a little portion of my flash light curve if my sync speed is to high compared to the duration of my flash? Regards

    1. Hi Zans, you could achieve whatever the fastest flash sync speed your HSS system will allow you. So for example if that was 1/4000th of a second shutter speed then that would be very similar to 1/4000th t0.1 flash duration. Of course the light levels you achieve with HSS are unknown because as you have pointed out the flash is cut off as part of the process. It will come down to a bit of testing to see how it works out. All the best Karl.

      1. Thanks for providing such a valuable lesson! Would using HSS (although its a workaround) work to freeze motion of fast flying liquids etc.? Would HSS allow me to use my cameras fastest shutter speed?

        1. Hi Molly, yes the purpose of HSS is to enable you to use fast shutter speeds with your flash. The downside is whether it will give you enough light and also if your shutter speeds achievable are fast enough to freeze what you want, the answers to this will only come by running some tests.

  2. Hello Karl

    I’ve been a fan for a very long time and have been watching your YouTube videos. I just signed up and became a member today and extremely excited. I’m currently on the Studio Lighting module and I must say that I’m learning a lot. I was always hesitant of Studio/Flashlights as it was unknown territory for me. But now, it’s actually making it very easy to understand and I’m not SCARED anymore :).

    Thanks again

    1. That’s great to hear and thanks for signing up. Make sure you watch the first class in the Lighting Theory section to as it’s very important to learning everything else.

  3. Hi Karl, Hoping you can help. I was planning on purchasing the Siros S kit but apparently, they can’t be sold in Australia at the moment (I think because of government regulation issues but I’m not too sure) and Broncolor does not know when they will become available again. It may take a long time… My question is, what is the main difference between the S and L series (apart from, obviously the L is battery powered). I need the lights for studio work… Should I hold out and wait and see what’s happening with the S series or just buy the L series? Cheers, Dan

    1. Hi Dan, I am surprised about the difficulties in getting hold of them! Yes the L is a lithium battery model, it can’t be plugged directly into the mains and it will be a little bigger and heavier but if you have spare batteries available on charge then you can always have one ready to swap out, the batteries are very good anyway and last for a decent amount of flashes even on full power, so you can use them in the studio or on location. You’ll see me using the L siros in this series of videos – https://visualeducation.com/section/environmental-portraits/

      1. Thanks, Karl. Appreciate the reply. One last question… Does the S siros have a faster flash duration than the L siros? If I were doing freeze-frame photography will the L siros work just as well as the S? Cheers, Dan

        1. Hi, according to the specs on Brons website the L version is actually slightly faster. I’ve used both and they are both good on high speed work.

  4. May be a dumb question, but were you using very fast shutter speeds too? Or just regular flash sync speeds. Thanks

    1. Hi just regular sync speeds. If the room had been completely dark I could have used a shutter speed last 2 seconds and it wouldn’t matter – shutter has no relation to fast flash duration, higher sync speeds are just useful for cutting out the ambient light in the room such as daylight, modelling lamps, interior lighting.

  5. Hi Karl, I’ ve decided to go with Paul C buff’s Enistain 640W/s units for my studio ligthing, and they claim a t.1 time at 1/256 power of 1/13.500 sec. which seem very very fast, and they also claim to be very very colour consistent in their output, why than is there so much price discrepancy between Broncolor and Paul C buff heads? Yes I’m aware that Paul C Buff lacks a lot of modifiers and they do not offer a dedicated studio power pack, but the lamps themselves seem like a very very good deal! Any thougths on that? Have you ever tried Paul C Buff yourself?

    1. Hi, I’ve never tried them or the Godox which I think have similar units. Some of the pricing difference is meant to be consistency, build and durability but I can’t comment on that not having used them.

  6. Hi Karl,

    I am well invested in the Elinchrom world (much like you were) and simply can’t afford to upgrade at this time. I have the ELB series and have always purchased the Pro heads because I was shooting architecture and didn’t need the fast flash duration. I am now trying to shift away from architecture and would really like to give splash photography a try, and need to invest in some heads that will get the job done.

    Elinchrom advertises their flash duration in t.05. The head that I’m considering reads as:

    Best flash duration t0.5 max. power ELB 1200 Action: 1/8850 s at 33%, power setting 4.7 / 172 Ws

    How would I know if 1/8850 in t0.5 is good enough? Thank you for your help Karl! =]

    1. Hi, T0.5 is a bit misleading as you would have discovered from watching this video. The speed they are quoting would be about 1/2500 in t0.1 which is respectable but not the fastest out there.

  7. Great stuff. Where do you think the line is between a fast flash and normal. Liquid and a moving fan is extremely fast but hair blowing in the wind or a fan is not as fast. Or maybe someone jumping. Rhetorical question almost but how fast does something have to be before you need a fast flash!?

    1. Hi Neil, if you think of it in the same terms as shutter speed, 1/500th – 1/1000th can freeze lots of things sufficiently such as hair, jumps etc so flashes with that duration speed can still be useful for many things.

  8. Hi Karl,

    It’s a pleassure start learning with you!!
    I looking for my first flash and I’m looking at my first flash for product and liquid photography like David Lund. However I have no money for a Broncolor Scoro. It is something that I have to work to achieve.

    I’ve seen this one from the Godox brand, the QT600II which it says has a:

    t.01 of 1/316 (1/25640) at 220v
    &
    then puts 1/190 (1/19606) at 110v.

    What does this mean? Is it a good light to start ??
    Until we can have a professional team?

    Thank you!!

    1. Hi Benny, yes it can – with the broncolor system the fastest flash durations are slightly bluer than their colour optimum settings.

  10. Hi Karl, after watching this video, wanted to test something with a Fan i have here, and found something interesting,

    Godox AD200 pro
    1/256 power.

    got 2 photos,
    1/200, perfectly frozen the blades.

    1/1000, got blur, both at same power 1/256, any reason this happens ?

    1. Hi, you’ve probably got ambient light pollution and didn’t shoot it in a darkened room or your modelling lights were left on.

  11. Hi Karl, I have a couple of questions just to make sure about:

    1- at 2:24, the Siros that you mentioned, is it Siros 800 S?
    2- If it is the Siros 800 S, I’m confused when you said it can attain 1/8500sec of flash duration with T.1 when on many websites they mention that the flash duration is 1/4000sec with T.1
    3- is it enough to freeze motion with 1/4000sec such as liquid splashes?

    Final question 🙂

    I would love to buy my first Broncolor and I’ve hesitated which one to buy, the Siros 800 S or Siros 800 L? I would love to take the opinion from an expert such as yourself.

    1. Hi Karl,
      don’t answer questions 2 and 3, some guy on youtube gave an update, and surprisingly the flash duration for Siros 800 L at power 2 and 3 is 1/9660sec, power 4 is 1/8550sec. He did a mistake to put back on the speed mode.

      just question 1 and Final question
      🙂

    2. Hi Ahmad, yes 800S, it can attain the very fast speeds from power 4.4 and lower. It can attain 1/9000sec at t0.1 which is equivalent to about 1/16,000th sec at t0.5

  12. After reading the specs of several flashes on the Broncolor website, I also see different flash durations depending on the maximum or minimum “energy level. being used. Based on your explanation about different flash units, some with a better ability to stop fast action, I’m assuming this is what you meant by being better able to stop fast action at a lower power setting. It would seem this would be another element to utilize creatively, depending on how much blur you want in the final image.

    1. Hi, yes generally speaking you get the fastest speeds out of the bron flashes from power 5 and lower.

  13. Hi, for the old petrol heads among us, this is the same principle as using a strobe light to adjust the pre ignition on old cars. The fly wheel has a mark and that needs to adjusted when the car is running idl. And in order the see if the mark is correct we used a strobe gun to freeze the mark. That you could tell if the pre ignition was early to late.

    Just some general info…

  15. Hi Karl, I would buy a strobe for splash photography and I saw that in one of your videos you have a Elinchrom Style RX600. There is someone close to where I leave that is selling two of them for 800 USD (almost never used) and I was wondering if you experienced their speed and if you would recommend them for splash photography. I am shooting in the laundry room or in my flat, the space is really limited and I do not need the light to be really strong. Or is there any model you would recommend? I would not spend more than 400/500 USD per light. Another option I found is a Phottix Indra 360 TTL (a bit out of budget though). Thanks and cheers MRfotostudio.

    1. Hi, no the RX600s are not really fast enough for splash work, Elinchrom do have some faster models now on their website with the specifications listed.

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