High Speed Flash Sync With Strobe?

[aaronrider]

Hi, I'm new to wireless strobes but I would like to start using one for outdoor sports. My only question is how I would go about using the high speed flash sync mode with a wireless strobe? Im using a canon 1d mark II which has a max sync speed of 1/250th when in normal mode. Of course im going to need a faster shutter speed when shooting fast sports. Id like to use a radio transmitter I suppose? Is there a certain transmitter I will need to get that supports high speed sync? Thanks!!

[SkipD]

I do not believe that what you want to do is possible. The Canon EX series Speedlites are the only flash units that I am aware of that can do the "high speed sync" thing, and I don't know if they can do it in master/slave mode.

Before you get too deep and serious about the "high speed sync" mode for the flash output, I suspect that you may not understand what flash triggering and flash sync'ing (flash synchronizing with the shutter) is all about and may very well not need to consider the "high speed sync" mode.

Ordinary flash output is a very fast single burst of light. The duration of the burst is a lot faster than 1/250 second. The reason for the max sync speed is the design of the shutter in the camera. The shutter is a focal plane design.

A focal plane shutter has two "curtains" (actually thin metal leaves in modern Canon cameras). One (which I will call the "leading curtain") is covering the film or sensor up to the time that you push the shutter release button. The other (which I will call the "trailing curtain") is positioned away from the film/sensor.

When you push the shutter release button, the leading curtain starts to move and uncover the film/sensor. For shutter speeds at or slower than the "max sync speed", the leading curtain will travel fully across the film/sensor plane and fully expose the film/sensor. Then, the trailing curtain will start to travel across the film/sensor, again covering it and blocking the light from hitting the film/sensor.

What is different at shutter speeds faster than the "max sync speed" is that the trailing curtain will start its travel before the leading curtain has finished uncovering the film/sensor.

As I stated before, most flash units have a burst time that is very short - on the order of 1/1000 second or even less (sometimes MUCH less). The key to synchronizing the flash to the shutter is to trigger the flash when the leading curtain has completely uncovered the film/sensor but before the trailing shutter has started to move, re-covering the film/sensor. If you set the shutter speed too fast (faster than the "max sync speed"), the flash will be triggered after the trailing curtain has started covering the film/sensor again and you will have a portion of the image that does not get exposed.

Now that we've looked at the basics of a flash exposure, let's discuss what the "high speed sync" thing is all about.

The "high speed sync" mode is primarily used when there is enough ambient light to take photos without flash but when you want to use flash to fill shadows on the subject. You may want to use, for example, a 1/1000 shutter speed for the ambient light. You now know that a conventional flash cannot work at that shutter speed. By putting the flash into "high speed sync" mode, it turns into a different animal altogether. What the flash will do is emit a rapid series of low-energy light pulses for the duration of the shutter's being open. The flash, in this mode, is trying to emulate a conventional light bulb.

Back to your sports thing - I suspect strongly that using a Speedlite in conventional mode would be more than adequate, assuming you are close enough to the subject for the flash to illuminate the subject. If you are too far away for a Speedlite to do the job, you may need a studio type of flash light. Either type of flash would limit your shutter speed to the "max sync speed", though.

When used in master/slave mode, the Speedlites are triggered remotely by a pulsed light beam which carries actual information between the camera and the Speedlite. You cannot use just an optical slave for them.

If you want to have a remote trigger system for a large flash system such a studio flash units, the best choice by far is a radio triggering system.

Does all this make sense? If not, we can go further into the basics so that you can understand the choices.

[aaronrider]

Hi,

Thanks for the detailed reply! I appreciate it. And yes, I have been researching how shutters work and I have a fairly good idea now. Its really ashame that canon has seemed to take a step backwards with their newer cameras when it comes to flash sync. The original 1D had a 1/500th sync.

Anyways, can you tell me how this photographer is able to take these pictures? He is using a wireless flash with the 1d mark II and the shutter speed is obviously much faster than 1/250. Thanks!

Faster than 1/250th. Most likely around 1/1000th...
http://www.hoppenworld.com/photogall...5_1098_jpg.jpg

http://www.hoppenworld.com/photogall...8_0006_jpg.jpg

http://img.timeinc.net/mx/content/im...5/KN1M6263.jpg

[aaronrider]

When shooting motocross there is really no way I can use a 1/250th shutter speed. The bike would simply be blurry from motion blur. They are traveling quite fast. I know it is possible to use high speed sync wirelessly with the speedlights, so why not a strobe? Thanks!!

[Curtis N]

High speed sync is a function of the flash, not the camera.

Only Canon EX Speedlites and a few aftermarket units are capable of high speed sync.

Further, the flash must be connected in a dedicated way so that the camera can report its shutter speed to the flash unit. This means it needs to be on the hotshoe, connected to an E-TTL compatible sync cord, or fired via Canon's wireless E-TTL system. It is not possible via other triggering methods such as PC cords, radio slaves or optical slaves.

It is certainly possible to get good shots of moving vehicles at 1/250 without blur. You need to be good at panning, take lots of shots and live with a relatively low keeper ratio.

[aaronrider]

HI,

Thanks, I am aware it is a flash function rather than a camera.

I guess my question is: if it is only possible using a canon transmitter for high speed sync, then what is the photographer in the photo using? How is he able to use high speed flash sync with that strobe?

I have been shooting motocross for several years now and have taken 20,000+ pictures of this sport. I am aware of what pictures look like with different shutter speeds. 1/250 simply does not give me the look I want (not even close) and is hardly ever used by anyone to photograph this sport. Yes, it will work for many other sports, but not this one. I like to see motion in the wheels, but thats about all. The slowest I can go is about 1/650. Most will have to be around 1/1000th.

I am simply trying to figure out what wireless device i can use that will allow me to fire a strobe at shutter speeds faster than 1/250th. I have a 550ex but a on camera flash is not an option because I will need to place a lighting unit closer to the track than I am standing, is not powerful enough, and does not have a quick enough recycle time. Therefore, I will need to use a strobe. What options do I have? I know its possible. There HAS to be some kind of transmitter that will fire a strobe in bursts similar to the canon speedlights.

I suppose I could stack a couple canon speedlights on top of eachother and buy the canon wireless transmitter to fire them so I could use high speeds, but I dont see why anyone should have to be forced to do this. It would be very expensive and still wouldnt have the power of a just one bigger strobe.

Thanks!!

[SkipD]

Originally Posted by aaronrider

I guess my question is: if it is only possible using a canon transmitter for high speed sync, then what is the photographer in the photo using? How is he able to use high speed flash sync?

What camera is that fellow using? I believe there are cameras that can sync with flash at faster shutter speeds than Canon's designs can. I could not tell you what they are, though.

I don't recognize the flash he's using, but it definitely does not appear to be a Canon Speedlite.

[aaronrider]

Originally Posted by SkipD

What camera is that fellow using? I believe there are cameras that can sync with flash at faster shutter speeds than Canon's designs can. I could not tell you what they are, though.

I don't recognize the flash he's using, but it definitely does not appear to be a Canon Speedlite.

He is using a canon 1d mark II. same as mine. And he is not using a canon speedlight, its a battery powered studio strobe similar to the one I am going to purchase.

I just had a thought, though. I never used strobes before, but wont it work with high sync speeds regardless of the transmitter or how advanced the lighting is? Cant I just set the shutter speed with a dial on the strobe? Then it will send out a flash of light that will cover the entire sensor just like the canon high speed flash sync speedlights? The only difference is it will use up more battery, but I dont care. Therefore, I can set the strobe to my fast shutter speed and it will fire. Right?

[FlashZebra]

If you must have a shutter speed faster than 1/250 second (or so) I suggest that you start investigating cameras that do not have focal plane shutters.

There are many high quality cameras that have in lens shutters (not focal plane shutters) where sync speeds to 1/500 second are pedestrian.

You also cite other cameras that allow the shutter speeds you desire, possibly you should start using those cameras.

If a high shutter speed sync is so important and an omnipresent issue for you, get a camera that provides that accommodation.

There are no devices for the current crop of Canon DSLR cameras that will provide the function you seek.

I suggest a bit more investigation on exactly how a focal plane shutter works, so you will understand the underlying issues, with regard to flash sync, that are fundamental to that shutter design.

Enjoy! Lon

[aaronrider]

Originally Posted by FlashZebra

If you must have a shutter speed faster than 1/250 second (or so) I suggest that you start investigating cameras that do not have focal plane shutters.

There are many high quality cameras that have in lens shutters (not focal plane shutters) sync speeds to 1/500 second are pedestrian.

You also cite other cameras that allow the shutter speeds you desire, possibly you should start using those cameras.

If a high shutter speed sync is so important and an omnipresent issue for you, get a camera that provides that accommodation.

There are no devices for the current crop of Canon DSLR cameras that will provide the function you seek.

Enjoy! Lon

For fast sports the only camera to use is the canon 1D mark II or the D2X. Believe me, I have tried others. So take your pick. No other camera has accurate enough Autofocus or speed. There is no other camera I desire more, I just desire their flash sync. Its ridiculous that canon and others cant put faster flash sync speeds on their $4000 cameras, but will on their cheap amateur cameras.

[René Damkot]

Originally Posted by aaronrider

Faster than 1/250th. Most likely around 1/1000th...

Based on what?
I see motion blur in the first two shots... My guess would be more in the region of 1/60s for the first shot.
If there isn't much ambient on the bike (like in the first shot: It's essentially backlit), using a slower time is very possible. The flash will freeze most motion.

Originally Posted by aaronrider

I guess my question is: if it is only possible using a canon transmitter for high speed sync, then what is the photographer in the photo using? How is he able to use high speed flash sync with that strobe?

Looks like a Quantum flash with a PW.
So he's *not* using HSS. Shutterspeed is 1/250 or lower.

Originally Posted by aaronrider

I have been shooting motocross for several years now and have taken 20,000+ pictures of this sport. I am aware of what pictures look like with different shutter speeds. 1/250 simply does not give me the look I want (not even close) and is hardly ever used by anyone to photograph this sport. Yes, it will work for many other sports, but not this one. I like to see motion in the wheels, but thats about all. The slowest I can go is about 1/650. Most will have to be around 1/1000th.

Not with flash, if you underexpose the ambient enough.

Originally Posted by aaronrider

I am simply trying to figure out what wireless device i can use that will allow me to fire a strobe at shutter speeds faster than 1/250th. I have a 550ex but a on camera flash is not an option because I will need to place a lighting unit closer to the track than I am standing, is not powerful enough, and does not have a quick enough recycle time. Therefore, I will need to use a strobe. What options do I have? I know its possible. There HAS to be some kind of transmitter that will fire a strobe in bursts similar to the canon speedlights.

Only option is using a camera with CCD instead of CMOS sensor: Some of them (Like Nikons D70, and Canons 1Dino) will sync at *all* shutterspeeds, since the shutterspeed is 'made' by switching the CCD on and off: The shutter curtains only go as fast as0 1/250s. So the entire CCD is exposed to the flash.

Originally Posted by aaronrider

I suppose I could stack a couple canon speedlights on top of eachother and buy the canon wireless transmitter to fire them so I could use high speeds, but I dont see why anyone should have to be forced to do this. It would be very expensive and still wouldnt have the power of a just one bigger strobe.

I suppose...
Then again, HSS won't freeze motion like an ordinary flash...
I'ld definately go for 1/250, panning and ordinary (non HSS) flash.

Originally Posted by SkipD

What camera is that fellow using? I believe there are cameras that can sync with flash at faster shutter speeds than Canon's designs can. I could not tell you what they are, though.

I don't recognize the flash he's using, but it definitely does not appear to be a Canon Speedlite.

Looks like a Quantum QFlash.

Originally Posted by aaronrider

I just had a thought, though. I never used strobes before, but wont it work with high sync speeds regardless of the transmitter or how advanced the lighting is? Cant I just set the shutter speed with a dial on the strobe? Then it will send out a flash of light that will cover the entire sensor just like the canon high speed flash sync speedlights? The only difference is it will use up more battery, but I dont care. Therefore, I can set the strobe to my fast shutter speed and it will fire. Right?

No. The flash needs to communicate with the camera for HSS. It sends out a burst of flashes at around 60kHz. There is no strobe around that will do that.

[SkipD]

Originally Posted by aaronrider

He is using a canon 1d mark II. same as mine. And he is not using a canon speedlight, its a battery powered studio strobe similar to the one I am going to purchase.

I just had a thought, though. I never used strobes before, but wont it work with high sync speeds regardless of the transmitter or how advanced the lighting is? Cant I just set the shutter speed with a dial on the strobe? Then it will send out a flash of light that will cover the entire sensor just like the canon high speed flash sync speedlights? The only difference is it will use up more battery, but I dont care. Therefore, I can set the strobe to my fast shutter speed and it will fire. Right?

Unless some manufacturer has replicated Canon's "high speed sync" functionality, the answer is that you cannot use any shutter speed faster than the max sync speed. It's just a matter of physics.

If the flash unit which the fellow in the picture is using can emit a series of rapid bursts (which is what the "high speed sync" function does), then you could use faster shutter speeds. Of course, there is a possible additional problem and that's the radio triggering timing.

I suspect what he may actually be doing is using the flash at full power and setting the aperture for the flash lighting at the distance of the rider while setting the shutter speed for the background exposure. The speed of the single flash pulse is short enough to stop the action in the air.

Is there any way you can talk to the photographer in the photo? I assume you took the photo.

As an afterthought, I went to the fellow's web site and looked at his equipment list. It is quite possible that the light being held by the assistant is not a flash unit at all but a continuous light. He lists 2000-watt and 1000-watt continuous lights in his kit. That could be possible with the huge battery the assistant is carrying. Maybe it is a very long-duration flash as well. That would allow him to sync at a higher shutter speed.

[aaronrider]

Originally Posted by SkipD

Unless some manufacturer has replicated Canon's "high speed sync" functionality, the answer is that you cannot use any shutter speed faster than the max sync speed. It's just a matter of physics.

If the flash unit which the fellow in the picture is using can emit a series of rapid bursts (which is what the "high speed sync" function does), then you could use faster shutter speeds. Of course, there is a possible additional problem and that's the radio triggering timing.

I suspect what he may actually be doing is using the flash at full power and setting the aperture for the flash lighting at the distance of the rider while setting the shutter speed for the background exposure. The speed of the single flash pulse is short enough to stop the action in the air.

Is there any way you can talk to the photographer in the photo? I assume you took the photo.

OK, im looking at a the strobe specs for a standard 300m/w strobe and it says it has a sync speed of 1/600-1/1600. Does this mean I can use my camera at these speeds? So why cant I just set the strobe to fire a constant burst that lasts throughout the entire shutter actuation? If i want to take a picture at 1/1000th, cant I just set the strobe to fire a burst 1/1000 long, also? This way the flash will cover the entire sensor. Whats wrong with it just sending out a constant beam that is the same duration as the shutter speed? This is basically the same way a canon speedlight works in high speed mode except without pulsing to conserve the flash battery, right?

As for the photographer, no. I dont know him personally. His name is frank hoppen and is considered to be the best motocross photographer in the world by many. He does alot of his work using strobes and such and I would like to try out some of his techniques.

[aaronrider]

[quote=René Damkot;3668014]Based on what?
I see motion blur in the first two shots... My guess would be more in the region of 1/60s for the first shot.
If there isn't much ambient on the bike (like in the first shot: It's essentially backlit), using a slower time is very possible. The flash will freeze most motion.

[quote]

Nope, im 100% positive he is not using a shutter speed slower than 1/250th. I can tell because of the wheelspin. These guys are moving fast! Even for a bike going a fairly slow speed you cant see the spokes or knobs of the wheels at all at 1/250th. At about 1/650th the wheels will start become very blurry. Most of his pictures were taken at speeds between 1/650- 1/2000. Positive.

[FlashZebra]

Originally Posted by aaronrider

OK, im looking at a the strobe specs for a standard 300m/w strobe and it says it has a sync speed of 1/600-1/1600. Does this mean I can use my camera at these speeds? So why cant I just set the strobe to fire a constant burst that lasts throughout the entire shutter actuation? If i want to take a picture at 1/1000th, cant I just set the strobe to fire a burst 1/1000 long, also? This way the flash will cover the entire sensor. Whats wrong with it just sending out a constant beam that is the same duration as the shutter speed? This is basically the same way a canon speedlight works in high speed mode except without pulsing to conserve the flash battery, right?

As for the photographer, no. I dont know him personally. His name is frank hoppen and is considered to be the best motocross photographer in the world by many. He does alot of his work using strobes and such and I would like to try out some of his techniques.

You need to educated yourself on how a focal plane shutter actually works. Until you actually understand that functionality, all this will never add up for you.

Enjoy! Lon