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09/26/2007 07:38:24 PM · #1 |
I GOT MY LIGHTING SYSTEM! i am so happy...
but....
The radio flash trigger system I got will only sync up to speeds of 1/250 seconds....so I can't use a faster shutter speed than that if i want to use the radio trigger, i never thought about that until I got it now and started playing
is this normal? are there radio flash trigger systems that have faster ones? microsystem has 1/180 top speed and I was looking at pocketwizard and looks like theirs doesn't go much higher
just curious about whether or not im crazy :)
claire |
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09/26/2007 07:44:01 PM · #2 |
You're shutter won't sync any faster than that anyways.
Yeps, mostly normal.
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09/26/2007 07:46:30 PM · #3 |
really?
hmmm
i had no idea! over the summer using the synce chord i was doing speeds up to 1/4000....makes for cool jumping pictures....but if that's normal then bring it on :) |
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09/26/2007 07:55:34 PM · #4 |
Originally posted by lovethelight:
really?
hmmm
i had no idea! over the summer using the synce chord i was doing speeds up to 1/4000....makes for cool jumping pictures....but if that's normal then bring it on :) |
sync cord for your sony flash, correct? I'm not really all that familiar with their system, but it's probably some flavor of high-speed sync.
I have some wireless triggers that will sync up to 1/1000, but only if I use it with the D70. That's only because it's using the electronic shutter instead of the physical shutter to capture the light.
If you do incrementally jack up your shutter speed on manual, you'll begin to see successive blacking out of your frame as the shutter opening is caught by the beginning of the flash output. Depending on what power setting you have the new lights at (AB's right?), the time for that flash is a maximum of about 1/1000 of a second.
Some photographers, because of this limitation, have taken to shooting with smaller flashes instead of strobes when they want to open up wide in a small space. The only other option is to move the lights back and get your inverse square effect going to kill some light. |
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09/26/2007 08:03:11 PM · #5 |
Oh, as for the jumpin pics. As long as you're in a dark enough room, the short duration of the flash will still freeze the action.
You'll usually be shooting between f/7 and above so indoor ambient at low ISO will be pretty negiligible. Put the lights close in (or turn up the power) with a higher f/ and it's the same as the ambient not being there at all.
Message edited by author 2007-09-26 20:03:52. |
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09/26/2007 08:17:53 PM · #6 |
Unless this is wrong... the specs on your camera that I found on the internet suggest that your shutter sync speed is actually slower than that:
Flash Sync Speed: 1/160 seconds (with Super SteadyShot off), 1/125 seconds (with Super SteadyShot on)
However, it does have a high speed sync option with certain flashes:
High-Speed Sync (with HVL-F56AM or HVL-F36AM Flash)
The flash sync speed of your camera suggests that the curtains travel at the fastest speed of 1/160th of a second.
Let me explain.
There are two curtains. At 1/160th of a second, the first one has finished opening when the 2nd one begins to close. At any speed faster than that, the first one will not have finished crossing the sensor plane before the 2nd one begins to close. At your fastest shutter speed (1/4000th), there is barely a slit between the first and second curtains. The first curtain opens and 1/4000th of a second later the second curtain begins to close. And 1/160th of a second later, the 2nd curtain finishes closing. Meanwhile only 1/4000th of a second of light has reach any portion of the sensor.
Now, the problem with flashes is that the flash duration is SHORTER than the length of time that the curtains are open.
So the only way to sync with a flash that is faster than the curtains is to: 1) wait for the first curtain to be all the way open before firing the flash, and 2) make sure that the 2nd curtain hasn't started closing before the flash has fired.
And there you have it ... flash sync speed.
BUT WAIT ... she says ... what about high speed sync?!?!?!?
Ah, the tricky part here is that, in order for your flash to sync at speeds higher than 1/160th of a second, the FLASH DURATION must be extended to 1/160th of a second! In other words, you have to SLOW DOWN the flash, in order to SPEED UP the shutter! (let your mind bend over that one for just a moment)
What they generally do is quickly "pulse" the flash several times during that 1/160th of a second in order to keep the flash output going while the curtains cross the sensor plane. So, as a side note, you actually use up batteries quicker (if you're flash is battery powered) in high speed mode than in normal mode. So your best bet is to only turn on high speed mode when necessary.
Hope this helps clear things up. :-)
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09/26/2007 08:20:26 PM · #7 |
P.S.
You can easily test this... meter your lights to something like f/8. Then set your camera to 1/60 and f/8 and fire. Try again at 1/125 and f/8. You should see the exact same exposure. Try again at 1/160th. Same thing, right? Now, as you move upwards beyond 1/160th of a second, you'll probably see a black bar creep across your image (from the bottom up or top down depending on which direction the shutter is going). The shorter the duration (faster the shutter), the wider the black bar becomes.
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