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  • #262660
    Profile photo of tanhbtanhb
    Spectator

    Do not know where should I post this question, in the Eager to Learn section or in this section. Mod, please move it to the appropriate section if it doesn’t belong to here. Thanks.

    The EXIF data for the below link image is, EOS 5D, 300/2.8IS, 1/250 @ f18, ISO 200, multi flash set-up.

    1/250sec? How the photographer managed to freeze the wings with this shutter speed?
    Does multi flash setup help to freeze the motion? My understanding is no. :?

    http://www.naturescapes.net/phpBB3/viewtopic.php?f=3&t=154007

    #287326

    Hi Hwee Boon,

    The secret is Canon, only Canon can do that. :D

    Seriously, this is because of multiple flashes set up. Graeme wrote in the old site about how this things work, but unfortunately, the site is gone. Anyway, the shutter speed from the camera is irrelevant. When you underexpose the ambient by 3 stops and above (he was using f/18 at 1/250s), and use manual flashes setting at 1/16 or 1/32, essentially you only expose for that short pulse of light may be about 1/20000 – 30000s. Therefore the wings are frozen. Go to the PageOne Exhibition, the Hummingbird Hawk Moth by Yan Leong is also using the same theory to freeze the wings.

    Cheers,
    SC

    #287330
    Profile photo of tanhbtanhb
    Spectator

    Hi SC,

    Yes, Canon is the answer, I will make sure I dump my Nikon and get a Canon tomorrow. :D

    Thank you for the explanation, your reply prompt me to do a search on the internet for this technique. I included a link here to an article on this technique for those who are interested.

    Even this article described this technique using Canon equipments. :doh_alamak:
    http://www.naturescapes.net/022004/jb0204.htm

    #287331

    Hi Hwee Boon,

    Here is another article on this topic: http://www.naturephotographers.net/articles0903/jm0903-1.html. Sorry, also Canon equipment. :twisted:

    Cheers,
    SC

    #287350
    Profile photo of ong_wsong_ws
    Member

    Hi Hwee Boon

    As mention by SC that Graeme had wrote some artical on High Speed Photography or Multiflash in the old site,
    i manage to save it in Text document for my future reference. This is the content and hope its useful to you.


    There seems some confusion on the high speed flash issue and the last few postings have essentially got it dead wrong. I will try to make it clear here. Sorry no images go with it but it is best to post where the demo is occuring.
    High speed flash.

    To achieve this you need flashes than can be put on manual setting and dialed down to at least 1/16 power. This is a slight misnomer as the intensity of the flash is constant but the duration is less.
    Here is how it works
    Say at full power your flash duration is 1/1000
    At half power it will be 1/2000
    At quarter power it will be 1/4000
    At one eighth power it will be 1/8000
    At one sixteenth power it will be 1/16,000
    At one 32nd power it will be 1/32,000…… which is a seriously fast speed.

    You need to trigger the flashes…which can be done via hard wiring or via a master/slave mode (via infra-red or via light intensity)

    You will need all flashes and there should be at least 4 set at the same speed. Different brands may not have the same output features so it pays also to have the same species of flash.

    You must remember that when you set your camera to f16 at 1/250 (to trigger the flashes) you get the ultra fast 1/20,000 (say) but your shutter remains open for 1/250…..and this becomes a problem

    Say ambient light is f16 at 1/100…..and you want to set your aperture at f16 for your high speed shots. What you need to do with your settings is to take ambient exposure out of the reckoning. With hummers if you have your camera setting at 1/250 to trigger the flash….the birds wings will be blurred against a light natural background…because f16 at 1/250 has not eliminated ambient light. To freeze wings you need to light your background with the same light as the bird/bug…..that is why you need an artificial background. It is also best to shoot in conditions less than sunny 16 to make sure you eliminate the effects of ambient light. So say ambient light is f8, 1/100 iso 100 then if f16 @ 1/250 would represent over 4 stops underexposure so essentially no effect of ambient light therefore your bird/bug is exposed at around 1/20,000 at f16 and the wings should not be blurred (with the proper flash set-up) and no ambient light effects.

    The downside of dialing flashes down like this is that they must be relatively close to the subject. ……..butthe essential thing to remember is that your flash duration becomes your shutter speed.

    ( i forgot if this Sunny 16 rule is part of his text, but then i just add it in)
    SUNNY 16 RULE

    When caught without a meter, one can use the "Sunny 16 Rule" as a guide for exposure. There are two steps to the rule, as outlined below:

    STEP 1: Set your shutter speed equal to your film speed.

    (i.e., Shutter = Film Speed)

    Examples: 1/60 for Velvia rated at ISO 50; 1/125 for TMax rated at ISO 100. Note that in most cases, the shutter speed will NOT EXACTLY EQUAL film speed, but will be set as close as possible to the film speed. It’s simply easier to remember the rule as "Shutter = Film Speed."

    For example, to shoot ISO 100 film in sunny conditions, set the shutter speed to 1/100 or 1/125 and the f-stop to f/16. With ISO 200 film, set the speed to 1/200 or 1/250. For ISO 400 film, 1/400 or 1/500. As with other light readings, the shutter speed can be changed, as long as the f-number is compensated. For example, 1/250th of a second at f/11 would be equivalent to 1/125th at f/16

    STEP 2: Set your aperture equal to f/16 for sunny sky.

    What if it’s not sunny?
    If slightly overcast, open one stop to f/11. If overcast, open two stops to f/8. If deeply overcast, open three stops to f/5.6.

    How do I distinguish between slightly overcast, overcast and heavy overcast?

    Examine the shadow detail. If shadows are distinct but soft around the edges, then it’s slightly overcast. If shadows are not distinct, but still visible – very soft – then it’s overcast. If there are no shadows at all, then it’s heavy overcast.

    The chart below provides a useful summary:

    SUNNY 16 CHART
    Aperture
    Lighting Conditions
    Shadow Detail

    f/16
    Sunny
    Distinct

    f/11
    Slight Overcast
    Soft around edges

    f/8
    Overcast
    Barely visible

    f/5.6
    Heavy Overcast
    No shadows

    #287351
    Profile photo of tanhbtanhb
    Spectator

    Hi ong_ws,

    Thank you very much for putting up Graeme’s article on high speed flash again on this new site, appreciate it. The article was very well written and easy to understand, thanks Graeme for the knowledge sharing. :kudos thumbsup:

    SC,
    Thanks for the link too, but could you please post something not related to Canon, may be an article on how my Nokia handphone camera can do high speed flash. :nyah nyah:

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