Off Camera Flash question

[burstintoflame81]

I have recently bought two Cowboy Studios wireless triggers that cannot transmit TTL. The specs for my flash says that its speed is Approx. 1/500〜1/13,000 sec, so how do I get that to work with a fast shutter speed? I tried shooting faster than 1/200th of a second but the light must fall off because half the image is black. Is there a trick to doing this or is the flash not capable? ( Its a Sunpak PZ42x )

 

[burstintoflame81]

Why not?

 

[burstintoflame81]

So you are saying that the camera can't trigger the flash quickly enough?

So is there a way that I would be able to fire this flash with a shutter speed in the 1/1000th range or higher?

 

[burstintoflame81]

Cool, thanks. Would a 7D be able to?

 

[ghache]

no FP mode?

 

[ghache]

i just made some research, FP only works if you have a ttl flash.

 

[Village Idiot]

no FP mode?

Some explanation may help.

The 1/500-1/13,000 listed on your strobes is their duration.

When shoot with a flash, you're getting two exposures; you're getting the ambient which is limited usually to 1/160-1/200 max shutter speed (called flash sync or x sync) and you're getting the strobe's duration which for your lights is between 1/500-1/13,000.

Normally a strobe's flash duration gets faster as the power is dropped and longer as the power is increased.

If you're trying to stop action and just get the exposure of the flash, shoot at the lowest ISO, your camera's x sync (1/200?) and narrow the aperture down to help kill the ambient. Then you would expose with the flash and the pop of light from that would be fast enough to freeze the action.

The real trick is if you want to mix ambient and try and stop action. Then you have to balance two different exposures and work with the movement to try and not get trails.

So why exactly do you need a faster speed?

 

[KmH]

no FP mode?

Canon calls it HSS.

I don't know if the T1i has HSS.

At any rate as Village Idiot points out flash duration is often used to stop motion instead of shutter speed when using flash.

I know a Nikon SB-600 has a flash duration of 1/1000 sec at full power and a flash duration of 1/20,000 sec at 1/64th power.

It's one of the really neat things about using flash.

Welcome to the exciting and technical world of strobed light photography.

Make a note though; if you use HSS the speedlight cannot fire at anything near full power because it has to fire several times during a single exposure.

Consider WHY there is a flash sync speed limit.

The shutter has 2 curtains. Canon calls them the first and second.

At the T1i's max flash sync speed of 1/200 the first curtain is fully open and the second curtain has not yet started to close when the flash fires, so one flash at full power can occur because the shutter is fully open.

At shutter speeds faster than 1/200 the second curtain starts to close before the first curtain has fully opened meaning the shutter opening is just a slit. It's a pretty wide slit at 1/250 but when the flash is not in HSS mode and fires, one of the curtains will be covering part of the shutter opening. The slit gets narrower the faster the shutter speed.

Which one will be covering part of the opening will be determined by the flash curtain sync setting. The camera can be set to fire the flash at the same instant the first curtain is fully open (which means the second curtain will be blocking part of the upper part of the shutter opening) or it can be set to fire at the instant the second curtain starts moving to close the shutter opening (which means the front curtain will be blocking the lower part of the shutter opening).

Either way the image has a dark section at the top or bottom in landscape mode and left or right in portrait mode.

That's why HSS fires the flash several times during an exposure, to compensate for both curtains.

 

[aliciaqw]

Is this something that can be resolved with a better flash?

 

[dyyylan]

Is this something that can be resolved with a better flash?

I believe it has to be on the camera as well, in order to do it on my d90 I have to turn on "Auto FP" on the camera and that lets me get above 1/200 with my sb-600, but only when it is attached to the hotshoe, I can't use CLS with auto fp. so i'd say it has to be with the body + speedlight. with auto fp turned off, it wont go past 1/200 no matter what if i have any flash enabled (on camera or hotshoe'd)

 

[Village Idiot]

Is this something that can be resolved with a better flash?

No. You either use a proprietary speed light for it's high speed sync mode which drains batteries faster and loses power compared to firing just one burst of light or you stick to the x sync.

There is another method, but it entirley depends on the camera. I believe the d50, d70, d40, Original 1D, GXX series, and several other cameras can do this. They operate with a shutter mechanism that allows it to electronically turn on and off. The manuals in most of these cameras say that the x sync is 1/500, but as long as you're triggering the light remotely and not via the hot shoe or commander mode, you essentially have an unlimited x sync.

I believe there may be another way to do this as well, but I'd have to test it out.

 

[burstintoflame81]

Thanks for all of the info guys. Yes, I had attempted to shoot above 1/200th ( or maybe it was 1/250th ) but the next speed higher resulted in a half black picture.

I mainly was just trying to learn incase I wanted to shoot something fast, like a Hummingbird hovering at a feeder or someone sprinting and be able to get a total frozen motion image. I have two triggers and two flashes, and a wireless remote for the camera. So I was just trying to figure out what I am capable of for future ceativity.

 

[burstintoflame81]

I just tried full speed 1/4000th of a second with the flash mounted to the camera and it worked perfectly ( although I had to turn down the flash comp just a tad ) So atleast I know I can just use on camera is I really need to shoot something fast, or get a TTL cord.