Your flash can't do highspeed mode, your camera isn't set to HS or your TTL doesn't work. In HS mode there is not only one flash, but a series of short duration flashes, thus bringing light to every part of the sensor while the shutter is moving across it. in normal mode there's one flash when the shutter is wide open for a 200th of a second. now, if the shutter is faster, only part of the sensor get's light (you probably knew that already)
makes sense but here is what i dont get, my flash according to specs dumps at 1/800, set off camera with a cheap radio trigger my camera simply tells it to fire and it does since there is no communication besides that. so if what you say is correct shouldn't be able to sync all the way up to 1/800 or is the flash dumping at a slower speed?
Unless the flash is set for HSS, which I don't think any dumb trigger supports, your sensor is only going to be fully exposed for 1/200th of a second. Anything over this will need the relatively continuous light of HSS to light the whole frame.
I am not sure what "dumps at 1/800" means, but I can only speculate that maybe your flash only supports HSS up to this speed. When off camera, it will still require something to trigger it that supports HSS.
The shutter must be fully open when the flash fires, to expose the entire area of the photo frame in that instant. Above the maximum shutter sync speed (sounds like 1/200 in your case) your camera's focal plane shutter is never fully open all at once, it is only a narrow open slit moving across the frame. This means faster shutter speeds cannot be used for flash, or else we would get a dark unexposed band in our picture, where the total frame area was not open.
The shutter must be fully open when the flash fires, to expose the entire area of the photo frame in that instant. Above the maximum shutter sync speed (sounds like 1/200 in your case) your camera's focal plane shutter is never fully open all at once, it is only a narrow open slit moving across the frame. This means faster shutter speeds cannot be used for flash, or else we would get a dark unexposed band in our picture, where the total frame area was not open.
ok, i think this is my issue in understanding this. i had assumed the shutter is opening fully. the flash i have fires at he equivalent of 1/800, so it can freeze motion in dark as a 1/800 shutter speed correct? i had assumed if my shutter was open for any duration up the that equivalent shutter speed than i should have no problem. but if the shutter isn't fully open the frame will get exposed for during fired during that sliver.
I'm not sure what a flash rating of '1/800s' means. The duration of the actual flash itself is something like 0.00003 seconds, or 3/100000s.
The limit that applies here is the sync shutter speed of your camera (regardless of what the flash says) - Anything shorter than 1/200s and the shutter will be visible in the frame. Attaching a 'higher rated' flash doesn't change that.
ETA: Besides, if you're doing this in the dark. You can trigger your '1/800s' flash, and any shutter speed less than 1/200s on your camera will work (e.g. 1/60 or whatever) as the scene is still frozen for that 0.00003 seconds instant - But you *can't* go below 1/200s (1/400, 1/800 they won't work)
I'm not sure what a flash rating of '1/800s' means. The duration of the actual flash itself is something like 0.00003 seconds, or 3/100000s.
The limit that applies here is the sync shutter speed of your camera (regardless of what the flash says) - Anything shorter than 1/200s and the shutter will be visible in the frame. Attaching a 'higher rated' flash doesn't change that.
ETA: Besides, if you're doing this in the dark. You can trigger your '1/800s' flash, and any shutter speed less than 1/200s on your camera will work (e.g. 1/60 or whatever) as the scene is still frozen for that 0.00003 seconds instant - But you *can't* go below 1/200s (1/400, 1/800 they won't work)
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I'm not sure what a flash rating of '1/800s' means. The duration of the actual flash itself is something like 0.00003 seconds, or 3/100000s.
The limit that applies here is the sync shutter speed of your camera (regardless of what the flash says) - Anything shorter than 1/200s and the shutter will be visible in the frame. Attaching a 'higher rated' flash doesn't change that.
ETA: Besides, if you're doing this in the dark. You can trigger your '1/800s' flash, and any shutter speed less than 1/200s on your camera will work (e.g. 1/60 or whatever) as the scene is still frozen for that 0.00003 seconds instant - But you *can't* go below 1/200s (1/400, 1/800 they won't work)
The 1/800 refers to the t.1 time of the flash, which is the duration. There are also t.5 times, but it's likely a t.1 time.
For a great visual of what happens when you go above your sync speed, you can watch this video.
hypersync in some pocketwizard options lets you exceed the sync speed - tested this with Canon flashes and tt1 tt5 combo. you also lose some power i think - its been a while and i've been staying away from the feature (haven't really needed it)
hypersync in some pocketwizard options lets you exceed the sync speed - tested this with Canon flashes and tt1 tt5 combo. you also lose some power i think - its been a while and i've been staying away from the feature (haven't really needed it)
This is true- hypersync is always lower in power because what the flash essentially does is pulse throughout the duration of the shutter stroke. So yeah, hypersync flash is always WAY less power, each stop higher you go for shutter you lose nearly the same in power. This is why leaf shutters are so awesome, since you don't suffer from this.
I'm not sure what a flash rating of '1/800s' means. The duration of the actual flash itself is something like 0.00003 seconds, or 3/100000s.
The limit that applies here is the sync shutter speed of your camera (regardless of what the flash says) - Anything shorter than 1/200s and the shutter will be visible in the frame. Attaching a 'higher rated' flash doesn't change that.
ETA: Besides, if you're doing this in the dark. You can trigger your '1/800s' flash, and any shutter speed less than 1/200s on your camera will work (e.g. 1/60 or whatever) as the scene is still frozen for that 0.00003 seconds instant - But you *can't* go below 1/200s (1/400, 1/800 they won't work)
The 1/800 refers to the t.1 time of the flash, which is the duration. There are also t.5 times, but it's likely a t.1 time.
For a great visual of what happens when you go above your sync speed, you can watch this video.
That explains a lot. I never realized my shutter behaved differently over 1/200 and I'm getting a better understanding how HSS works.
And remember, too, that a given flash will have a different duration at different settings. Speedlights will gain speed as you lower power, while some studio lights (like Alien Bees (Einstein excluded)) will actually LOSE speed as you lower power. It's important to look at how durations vary based on power settings to understand what to expect.
