Flash duration, daylight, freeze action

Discussion in 'Sports' started by laichungleung, May 27, 2021.

  1. Does very short flash duration help freeze action if you are shooting in broad daylight? Let's say the X sync is 1/250 and you are shooting at f/16 as the system doesn't do high speed sync, hyper sync or hi sync. It can only do X-sync. So you have a super fast strobe with short duration, will that freeze action like people riding a bike or skateboarding? If ambient is very low or totally dark in those shutter and aperture combination then I can see the benefit of a short flash duration in stopping action, but perhaps not so much in broad daylight? Want to hear your experience or opinion....
     
    mikemorrell likes this.
  2. In daylight, flash is usually used as a fill light. Freezing sports action outdoors in daylight should only require the correct ISO and shutter speed, which may need adjusting. I'd probably shoot 1/500 or higher, depending on the ISO. These images were shot on the same day, same field, no flash.:) sports.jpg 300mm 1/640 f/2.8 ISO 200 sports_same_day.jpg 100mm 1/250 f/5.6 ISO 100 sports-thecall.jpg 100mm 1/500 f/5.6 ISO 100
     
    luis triguez and bobbudding like this.
  3. Flash is useful for freezing action indoors, if the flash is powerful enough to light 2 or more stops above ambient levels. Outdoors? mpressionz has given excellent advice.
     
    mpressionz likes this.
  4. In the 80's I bought a Canon T-90 with second curtain flash sync which you need for the situation you describe. It was the Canon or Vivitar flash brochure, at the time, that showed awesome effects of daylight motion blur behind the subject and then the subject frozen by the flash. This was an effect I was excited about trying, but have never done it.

    I believe most cameras these days have second curtain flash sync available. If you use standard first curtain flash sync then the subject is first frozen then you get the motion blur in front of the moving subject.

    Here is an article discussing the above:

    Flash Blur Fun - Digital Photo Magazine

    If these affects are what you are talking about you will simply need a lot of trial and error and experimenting.

    Thank-you for reminding me of this because I have a camera and flash that can do this. So much easier to try this with digital!
     
  5. thanks all.
    i shoot some sports, mainly bike racings. I tend to add flash to add some spark to the pictures otherwise I feel like the lighting is too flat, i.e. if action is close and I am shooting with a wide angle like 16-35. Mostly I shoot at a low shutter speed (1/30s) and small aperture (f/8 or smaller), if front curtain curtain sync, the ghosting appears in the front, if rear sync, the ghosting appears in the end of the action which is usually more natural and desirable. So that's rear curtain sync.
    My question is actually on flash duration on action shots during daylight. I have seen numerous youtube video extolling the merits of fast flash duration which I have no way of testing in all scenarios as I don't own any 200w/s strobes with fast flash duration so I can only imagine....I tend to agree and from my limited experience, if I were to shoot in broad daylight with some below 100w/s flash, there is no way I can use flash duration to stop any action, that's based on flash duration to produce crisp images, instead I always use slow shutter and small aperture to pop the action. If I were to freeze any action I shoot 1/1000 or faster sans flash to freeze the action. So I just don't quite get it when people say flash duration to freeze actions, yeah I mean if you can totally overcome the ambient then sure but if I were to shoot outdoor, a long flash duration plus hypersync, i.e. using the camera's 1/500 or faster shutter speed would freeze the action...But I really have no experience ever having a power strobe with fast duration shooting action in broad daylight.
     
    mpressionz likes this.
  6. As well as I know it, full power flash are about 1/1000 s.

    Those that an reduce power do it by reducing the duration, so could be used for some fancy action freezing.

    Last I knew, sunlight is 76mW/cm2.

    Also, flash units should be quoted in W s, so you should be able to figure out the exposure
    time and distance to be somewhat more than daylight. I suspect you need to be close.
     
    laichungleung likes this.
  7. 1/1000 for full power flash is an old standard. Newer flash may have longer duration to around 1/300 s. The reason is that today battery powered flashes tend to have larger capacitor but lower voltage.
     
  8. I'd say that flash in daylight is best for shadow filling. These days i'd go for as high an ISO as you can tolerate.

    One drawback of flash is that you can get 'ghosting' where the sensor picks up some image from ambient light, and some from the flash, but not exactly at the same time.
     
  9. Great question!

    I'm only an amateur that very occasionally does sports photography. As far as I know, there are (at least} 2 approaches to the kind of sports photography that you describe.
    As far as I know, exposure is determined by two elements::
    - ambient lighting
    - additional lighting (such as a flash)

    The most obvious way of freezing action (without a flash) is by setting a high shutter speed (possibly sacrificing depth of field and ISO).
    A second way (an effect) is - as you describe it - is to combine the 'ambient light' with a flash exposure. Usually the second curtain. Depending on your 'ambient light' and flash settings, the result could be an ambient (motion-blurred) portrait of a sportsperson combined with a 'frozen' image of the sportsperson by the late-curtain flash exposure.

    I assume this takes practice;)
     
  10. I still have the Vivitar 283 that I got in 1979, though I don't use it much.
    So that is what I think of as a 'new' flash unit.
     

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