The main disadvantage to that is it's highly impractical for the primary reason you'd want that: Outdoors. You can technically do the same thing through careful use of a PW Multimax's delay feature, triggering the camera and the strobe separately but timed just right.
I can post a pic but I don't know what that will show? It just looks like a normal picture with strobe lighting and no black line from curtain
I own and experimented for weeks with multimax and it could not sync faster than 1/200, at 1/250th I start to get the black line from curtain.
I'm using 5dII with m2000wi packs, 580exii in high speed mode just as the trigger, The packs are set as optical slaves for trigger
It shouldn't be a problem to locate the packs outdoors together and then having the 580 flash pointing directly at them to trigger, i see this as a easy fix or even using the new pw flextt5 system to radio trigger the flash in high speed which is what they were really built for and you could have the flash pointing down directly above the optical slave
I'm recieving my flextt5 from bhphoto on tuesday we'll see if everything works out then. It's supposed to be able to high speed sync for canon flashes.
The main thing a test will show is how much power you're getting out of your strobe, though you could just tell us the exposure and distance instead. Also, was your 580 in ETTL HSS or M HSS? You make it sound like it's in M HSS at a low power setting, which would mean that it's being fired considerably before the exposure begins, which may very well be true and part of the reason why HSS is so inefficient. But hey, either way, good on you for experimenting.
hieuuu wrote:
I can post a pic but I don't know what that will show? It just looks like a normal picture with strobe lighting and no black line from curtain
The fact that 580 can trigger the Dynalite in HSS mode using white light slave does not mean that the Dynalites are contributing anything to the exposure, making the test meaningless.
No black line is probably evidence that there is indeed no exposure contribution from the Dynalites.
But, even if studio strobes could synchronize in HSS, your Dynalites would still need more time than 1/8000 to deliver their metered output since they most likely have a longer flash duration.
I'm recieving my flextt5 from bhphoto on tuesday we'll see if everything works out then. It's supposed to be able to high speed sync for canon flashes.
The reason the Flex works, albeit limited, in HSS is because:
A. Camera is able to communicate with a ETTL strobe, which it cannot do with a studio strobe.
B. Extremely short flash duration of a low power pulse from the 580. Studio strobe flash durations are typically shortest at their max power, but still much longer than a thyristor flash at low power.
Not sure why you'd want high studio strobe output with HSS ETTL functionality, but if you could it won't be as easy as you make it sound.
Synchronization is only one of many issues that would need to be addressed for studio strobes to work successfully at super high shutter speeds.
As Adam and Jamie would say, without pictures and EXIF, this Myth is............... busted.
cgardner wrote:
What is suspect what happening is that flash duration of your Dynalites is much longer than 1/8000th second, but the 580exII in high speed FP mode starts the flash pulsing slightly before the shutter actually opens which gives the optically triggered Dynalites time to fire and ramp up to full intensity just as the narrow shutter slit starts whizzing across the sensor. Since the flash duration is longer than the shutter speed the Dynalite is able to illuminate the entire frame evenly just as ambient light would.
I think you're exactly right. That's almost certainly what's happening.
The main disadvantage of this technique is you're losing power as you drop the shutter speed. In this situation you can treat your flash just like ambient --it's a constant light source for all intents and purposes. You're now back to the HSS pulsing sync problem: it kills your power. Obviously monolights and heads have more power to sacrifice, but it's the same problem.
Carmen Miranda's point is also well made. Depending on the timing and the power distribution of the strobe (t.1 & t.5 lengths), the big strobe may be contributing nothing or very little to the exposure.
I tried it at 1/1000 with 580 connected to my camera in high speed sync. as others have pointed out, you do loose power with the higher shutter, apparent with the light fall off.
snook wrote:
That does seem to be a big deal if you are using ab800 you cn just up the power a little to compensate for the fall off or no?
Snook
Not necessarily. Because you can't fine-tune the delay, you'd have to experiment to see if putting it at full power (and thus, quickest flash duration) works better than putting it at a lower power setting with a longer t.1, which may very well result in more light being available to the shutter. Also, any examples are worthless without a control shot using just the 580, no strobe.
That was simple for me to test by varying the strobe output. I could conclude the strobes were in fact lighting in sync, as for flash duration. that no longer matters because the camera is now using is electonic shutter of the sensor. Thats how it is able to sync with it's own flash system.
Ever wonder why you have a 1/8000 setting for shutter, this is why when you x-sync is only 1/200th. Electronic shutter. Maybe i'm just stuppid or something .
Will test further maybe a video on you tube. or maybe somebody else can try it on there system and let me know if they get similar results
hieuuu wrote:
That was simple for me to test by varying the strobe output. I could conclude the strobes were in fact lighting in sync, as for flash duration. that no longer matters because the camera is now using is electonic shutter of the sensor. Thats how it is able to sync with it's own flash system.
Ever wonder why you have a 1/8000 setting for shutter, this is why when you x-sync is only 1/200th. Electronic shutter. Maybe i'm just stuppid or something .
I wouldn't be so harsh as to say you're stupid --that's a little rough--, but you are mistaken on this . Only a few DSLRs have an electronic shutter.
High-speed sync within a manufacturer's system is done by pulsing the flash, essentially making it a continuous light source. At high enough shutter speeds, studio strobes essentially become continuous light sources as well. This is why you don't have black bars.
Jon Guilbault wrote:
High-speed sync within a manufacturer's system is done by pulsing the flash, essentially making it a continuous light source. At high enough shutter speeds, studio strobes essentially become continuous light sources as well. This is why you don't have black bars.
This is correct.
I just did some cursory testing with studio strobes triggered by ETTL speedlight in HSS mode and found the following preliminary results:
1. The flash in HSS does optically trigger the studio white slave flash
2. Both flashes (ETTL speedlight and manual studio strobe) are triggered to fire before high speed shutter opens and closes
3. The exposure catches the pulsed speedlight but only catches the tail end of the studio strobe.
4. The longer the flash duration of the studio strobe the greater the contribution to the exposure, as in the case of the AB800 above.
5. The higher the output of the studio strobe the greater the contribution to the exposure, except as mitigated by the shortening of the flash duration.
6. On a RX600, the exposure difference from 1/8000th to 1/250 was approximately 2.5 stops, which I believe may be due to light fall off caused by the diminishing tail of the flash duration.
7. I haven't done the final tally but here's the real kicker. The difference in the amount of light it took to get a properly exposed image (18% gray) at f4.0 using the studio strobe contribution only at 1/160th (x-sync ) and 1/2000th (HSS mode) was OVER 11 STOPS!!!!! Gadzooks.
Reality check:
That's ISO 100, f4, x-sync 1/160th with a Sports Magnum reflector on a Elinchrom RX600 positioned at 15' and powered down to minimum, 1/32nd power (17.5 WS).
Compared to same basic set-up using ETTL speedlight as trigger in HSS mode, camera set at 1/2000th and the RX600 moved within 3' of target and turned up to 100% (600WS).
A wonder it didn't burn a hole right through my V-flat.
And who knows, it might have taken a first order fresnel to get my exposure target to f4 at 1/8000th. Anybody have one of those in their cage?
I don't.
Yet.
Basically, trying to get a decent exposure with a studio strobe in HSS you're probably better off using the 250W halogen modeling light in really close. (May have to test that too. ) Your subject will probably still go blind, but at least they won't get flash burns too.
The best analogy I can think of when it comes to triggering studio strobes in HSS mode is like exploding a gas tanker truck just so you can light somebody up with the soft warm glow of it's smoldering remains.
Having said that, hieuu and CG have given me something to think about and there may be another twist to this insanity afterall. I'll keep you posted on the results.
Meantime, I'll try to post images of my test results sometime down the road, cause that's where I'll be for now.
Thanks for doing the test. I suspected that the process was a very inefficient use of the studio flash. But that could be mitigated by shooting at higher ISO, something you normally wouldn't consider with studio flash where the problem is usually too much power.
Also by experimenting with slower shutter speeds you'll perhaps be able to catch the studio flash at the more of the peak of output rather than as it trails off. As you slow the shutter from 1/8000, to 1/4000th, etc. eventually you'll see the point where the flash dies before the shutter slit gets all the way across. That will be evidenced by a dark band on the side opposite the x-sync shadow normally occurs.
I can see how this would be a useful trick for stopping action in a studio and/or shooting at wide apertures for shallow DOF at higher ISOs.
It also explains how the new Pocket Wizards raise the sync-speed. By intercepting the pre-flash command from camera-to-flash the PW can tell its receivers to start firing in advance of the shutter opening.
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
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 exposure will be affected, even below x-sync speeds, since ambient 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.
This is what the radio poppers are reported to do as well just like trigger the slaves but with the RPs it can do it by wireless radio so you do not need a slave. and up to 8000.
I hope to be getting one next week when the come out.
Things will be changing a lot with this function.
You will not need as much light power now.
Say good buy to high priced 1000 watt heads when you can do the same with 4 or 500 watt heads or less
The studio flash is only "continuous" for about 1/2000th sec. but that's more than enough time for the shutter set at 1/8000th (1/4 as long). The trick here is the timing, fooling the studio flash to start firing before the shutter opens.
As the shutter speed decreases the shutter curtains don't move any faster, the 2nd one just closes faster.
At 1/250th there is a 1/250th sec delay between the time the first curtain and second curtain movement. It probably takes about 1/400th sec for the first curtain to completely clear, then there's a delay of about another 1/450th sec, then the second curtain starts to close.
At 1/8000th it still takes about 1/400th sec for the first curtain to completely clear, but there's only delay of 1/8000th sec between when the first and second curtain start moving independently. The second curtain chases the first forming a narrow gap that zips across the sensor at about 1/400th sec.
The fact the slit exposing the sensor is actually moving relatively slow compared to the shutter speed is why rapidly moving objects traveling along the long dimension (opposite slit travel) may get distorted.
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