hieuuu wrote:
Wow so please explain to me how is that a digital slr has shutter speeds of 1/8000th for flashless shooting, is the sun pulsing? What is the camera doing then.
Maybe I am dumb but something besides the curtains is achieving this shutter speed. Since the curtains for my particular camera has max speed of 1/200th
Assuming you have a focal plane camera that has uber high shutter speeds, the 2nd curtain is following in concert with the 1st curtain to move a narrow slit over the frame to effectively achieve these short exposure intervals. The 2nd curtain does not wait for the 1st curtain to complete it\'s cycle before starting to close as it does at x-sync speeds.
The sun is a continuous light source. All light pulses, including the sun, but that\'s another story.
Continuous light can be captured at any shutter speed because it always available.
Strobes produce a brief burst of light that starts and drops off very quickly and then dies off over a longer period (flash duration) at a substantially reduced level.
Synchronization is critical for the main burst of light to be registered during the interval between the 1st curtain and 2nd curtain to properly expose the image. If the shutter speed is too short, the flash burst will go off as the 2nd curtain starts moving up to close the shutter. This will result in a dark band in the frame where the 2nd curtain is exposed as a shadow on the frame. X-sync speed is not the maximum speed of your shutter, it is the MINIMUM time that is required to properly expose a transitory interval of light created by a flash.
X-syncs are a rating, they are not a guarantee. There are many independent factors beyond the control of the camera that may require X-sync to be lengthened.
That\'s just the way it is with flash.
So what about HSS flash in M or TTL?
Read on, if you\'re still awake.
The key here is the camera is able to be tricked into setting the shutter at 1/8000th and still achieve a proper exposure.
The \"key\" here is NOT that the camera is tricked, but that your SPEED LIGHT is being \"tricked\" through TTL communication with the camera. Something you can\'t do with a manual studio strobe.
Essentially in HSS mode your speed light flash is turned into a continuous light source so that during a high shutter speed the light is available to be exposed. A flash is made \"continous\" by flattening it\'s output over a period of time. This is done by pulsing the light, like using short bursts of air to keep a balI in the air at a certain level. It may not appear that your flash is pulsing; it may even appear like it is flashing like a normal flash since it all happens so fast, but in actuality it is spreading out it\'s light energy over a longer period than a single burst of flash. This extended (still very short) period of \"continuous light\" is all that it is needed for the camera to register the light during an extremely short exposure without synchronization.
Evidence of this is the reduced output of the flash as it spreads out (pulses) it\'s energy. Total energy expended by flash is the same in HSS as in regular mode, but the level is not, since it is duration is extended.
Another clue that a speedlight acts like a continuous light source in HSS mode is that shutter speed DOES affect \"flash\" exposure, which DOES NOT occur in x-sync flash exposures.
In HSS mode more power, larger aperture or closer distances are required as the shutter speed goes higher, just as it would do with any other continuous light source. While below x-sync, shutter speeds have NO affect on flash exposure. Of course, the ambient is will be affected even below x-sync since it is a continuous light source.
Think of your speedlight in the regular mode as a burst that requires synchronization to be registered.
Think of your speedight in the HSS mode as becoming a rapid volley of smaller flash bursts (all totaling 1 full burst) that combine to become a continuous light for enough time to be seen by the camera at high shutter speeds.
Until a studio strobe can be \"tricked\" (not just triggered) into becoming a \"continuous\" light source like your ETTL speed light, it can not function effectively in HSS mode.
While the flash duration tail of a studio strobe is sufficiently flattened to act as a continuous light in HSS shutter speeds, it\'s level is far too low to be useful.
Triggering a studio strobe in HSS mode is the easy part, getting it work in HSS mode is another matter altogether and will require functionality to be built-in to studio strobe itself.
hieuuu wrote:
Wow so please explain to me how is that a digital slr has shutter speeds of 1/8000th for flashless shooting, is the sun pulsing? What is the camera doing then.
Maybe I am dumb but something besides the curtains is achieving this shutter speed. Since the curtains for my particular camera has max speed of 1/200th
Assuming you have a focal plane camera that has uber high shutter speeds, the 2nd curtain is following in concert with the 1st curtain to move a narrow slit over the frame to effectively achieve these short exposure intervals. The 2nd curtain does not wait for the 1st curtain to complete it\'s cycle before starting to close as it does at x-sync speeds.
The sun is a continuous light source. All light pulses, including the sun, but that\'s another story.
Continuous light can be captured at any shutter speed because it always available.
Strobes produce a brief burst of light that starts and drops off very quickly and then dies off over a longer period (flash duration) at a substantially reduced level.
Synchronization is critical for the main burst of light to be registered during the interval between the 1st curtain and 2nd curtain to properly expose the image. If the shutter speed is too short, the flash burst will go off as the 2nd curtain starts moving up to close the shutter. This will result in a dark band in the frame where the 2nd curtain is exposed as a shadow on the frame. X-sync speed is not the maximum speed of your shutter, it is the MINIMUM time that is required to properly expose a transitory interval of light created by a flash.
X-syncs are a rating, they are not a guarantee. There are many independent factors beyond the control of the camera that may require X-sync to be lengthened.
That\'s just the way it is with flash.
So what about HSS flash in M or TTL?
Read on, if you\'re still awake.
The key here is the camera is able to be tricked into setting the shutter at 1/8000th and still achieve a proper exposure.
The \"key\" here is NOT that the camera is tricked, but that your SPEED LIGHT is being \"tricked\" through TTL communication with the camera. Something you can\'t do with a manual studio strobe.
Essentially in HSS mode your speed light flash is turned into a continuous light source so that during a high shutter speed the light is available to be exposed. A flash is made \"continous\" by flattening it\'s output over a period of time. This is done by pulsing the light, like using short bursts of air to keep a balI in the air at a certain level. It may not appear that your flash is pulsing; it may even appear like it is flashing like a normal flash since it all happens so fast, but in actuality it is spreading out it\'s light energy over a longer period than a single burst of flash. This extended (still very short) period of \"continuous light\" is all that it is needed for the camera to register the light during an extremely short exposure without synchronization.
Evidence of this is the reduced output of the flash as it spreads out (pulses) it\'s energy while pulsing. Overall energy is the same, but the level is not.
Another clue that a speedlight acts like a continuous light source in HSS mode is that shutter speed DOES affect \"flash\" exposure, which DOES NOT occur in x-sync flash exposures.
In HSS mode more power, larger aperture or closer distances are required as the shutter speed goes higher, just as it would do with any other continuous light source. While below x-sync, shutter speeds have NO affect on flash exposure. Of course, the ambient is will be affected even below x-sync since it is a continuous light source.
Think of your speedlight in the regular mode as a burst that requires synchronization to be registered.
Think of your speedight in the HSS mode as becoming a rapid volley of smaller flash bursts (all totaling 1 full burst) that combine to become a continuous light for enough time to be seen by the camera at high shutter speeds.
Until a studio strobe can be \"tricked\" (not just triggered) into becoming a \"continuous\" light source like your ETTL speed light, it can not function effectively in HSS mode.
While the flash duration tail of a studio strobe is sufficiently flattened to act as a continuous light in HSS shutter speeds, it\'s level is far too low to be useful.
Triggering a studio strobe in HSS mode is the easy part, getting it work in HSS mode is another matter altogether and will require functionality to be built-in to studio strobe itself.
hieuuu wrote:
Wow so please explain to me how is that a digital slr has shutter speeds of 1/8000th for flashless shooting, is the sun pulsing? What is the camera doing then.
Maybe I am dumb but something besides the curtains is achieving this shutter speed. Since the curtains for my particular camera has max speed of 1/200th
Assuming you have a focal plane camera that has uber high shutter speeds, the 2nd curtain is following in concert with the 1st curtain to move a narrow slit over the frame to effectively achieve these short exposure intervals. The 2nd curtain does not wait for the 1st curtain to complete it\'s cycle before starting to close as it does at x-sync speeds.
The sun is a continuous light source. All light pulses, including the sun, but that\'s another story.
Continuous light can be captured at any shutter speed because it always available.
Strobes produce a brief burst of light that starts and drops off very quickly and then dies off over a longer period (flash duration) at a substantially reduced level.
Synchronization is critical for the main burst of light to be registered during the interval between the 1st curtain and 2nd curtain to properly expose the image. If the shutter speed is too short, the flash burst will go off as the 2nd curtain starts moving up to close the shutter. This will result in a dark band in the frame where the 2nd curtain is exposed as a shadow on the frame. X-sync speed is not the maximum speed of your shutter, it is the MINIMUM time that is required to properly expose a transitory interval of light created by a flash.
X-syncs are a rating, they are not a guarantee. There are many independent factors beyond the control of the camera that may require X-sync to be lengthened.
That\'s just the way it is with flash.
So what about HSS flash in M or TTL?
Read on, if you\'re still awake.
The key here is the camera is able to be tricked into setting the shutter at 1/8000th and still achieve a proper exposure.
The \"key\" here is NOT that the camera is tricked, but that your FLASH is being \"tricked\".
Essentially in HSS mode your flash is turned into a continuous light source so that during a high shutter speed the light is available to be exposed. It may not appear that your flash is pulsing; it might even appear like it is flashing like a normal flash since it all happens so fast, but in actuality it is spreading out it\'s light energy over a longer period than a single burst of flash. This extended (still very short) period of \"continuous light\" is all that it is needed for the camera to register the light during an extremely short exposure without synchronization.
Evidence of this is the reduced output of the flash as it spreads out it\'s energy while pulsing.
Another clue that the strobe in HSS mode acts like a continuous light source is that shutter speed DOES affect \"flash\" exposure, which does not occur in x-sync flash exposures.
Think of your flash in the regular high power mode as a burst that requires synchronization to be registered.
Think of your flash in the HSS mode as becoming a rapid volley of smaller flash bursts (all totaling 1 full burst) that combine to become a continuous light for enough time to be seen by the cameras high shutter speeds.
Good luck.
Mar 17, 2009 at 11:55 PM
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