newbie: what is slave and master flash?

[tenggiri10]

hi, need to know about the slave and master flash.

is the strobe is a master?

 

[sherwoodpete]

hi, need to know about the slave and master flash.

is the strobe is a master?

The master is triggered directly by the camera. One or more slaves are trigged not from the camera, but by the master.

Typically the light from the master is detected by a sensor attached to the slave which causes the slave to fire. This all happens so rapidly that it appears to be simultaneous. The link from master to slave might also be via infra-red or radio.

I'd prefer to reserve the word strobe for a flash which can fire multiple times very rapidly, producing results like this one:
http://www.newscientist.com/gallery/on-the-move/5

Regards,
Peter

 

[Mike_PEAT]

I'd prefer to reserve the word strobe for a flash which can fire multiple times very rapidly, producing results like this one:
http://www.newscientist.com/gallery/on-the-move/5

What you call a strobe is actually a stroboscope (which doesn't have to be xenon based, it can actually be incandescent, led, or other forms of lighting).

In photography though, a strobe is a large flash...and we're stuck with it. Just like we're stuck with the term "crop factor" for any sensor smaller than the misnamed "full frame" sensor.

 

[Mike_PEAT]

hi, need to know about the slave and master flash.

A slave (optical slave) is a device that's connected to another flash or large strobe that triggers that device to fire when it "sees" another flash firing.

Note though that most digital cameras/flashes fire a preflash which triggers the optical slave prematurely so that the slaved flash is actually dark for the exposure. In those cases you have to disable the preflash for it to work properly.

Also some brands have smart TTL flashes that can work wirelessly...these are also slaved from the main/master flash, but they receive a "morse code" of flash pulses which tell them how to light up the scene.

 

[sherwoodpete]

I'd prefer to reserve the word strobe for a flash which can fire multiple times very rapidly, producing results like this one:
http://www.newscientist.com/gallery/on-the-move/5

What you call a strobe is actually a stroboscope (which doesn't have to be xenon based, it can actually be incandescent, led, or other forms of lighting).

In photography though, a strobe is a large flash...and we're stuck with it. Just like we're stuck with the term "crop factor" for any sensor smaller than the misnamed "full frame" sensor.

Basically it's the difference between British and U.S. usage. Naturally I prefer the usage which is normal in my own land.

Similarly I shall continue to use the word "torch" for a hand-held device which emits a continuous light. Unlike other regions which use the term "flash-light" for such a device. Having already used the term "flash-light" for a continuous light, I suppose it was inevitable that there was no word remaining for an actual flash light.

As for the strobe effect, that can be produced by a simple mechanical device, such as a disk with many regularly-spaced holes, which is rotated rapidly, and the subject is viewed through the holes. Hence the derivation of the term from the Greek "strobos", meaning "act of whirling".

Regards,
Peter

 

[chuxter]

hi, need to know about the slave and master flash.

The "master" flash is in control of the "slave" flash(es).

is the strobe is a master?

Not sure what you mean?

There are many different configurations. The simplest and oldest is to have a photo-detector on each "slave" flash that fire it when the "master" flash goes off. Back in the good old days, there were no "slave" flashes...you bought a little adapter that you put a flash on...the adapter had the photo-detector to trigger the flash on top. Now-a-days, some flashes have photo-detectors built in...they work the same way, just more convenient...you just switch the flash to "slave" mode and voila'...

But there are more complex flashes too. Now-a-days, most flashes have a TTL-auto mode, where the flash emits a weak pre-flash and the camera looks at the exposure and computes how much light the flash must produce for the exposure, then sends a command to the flash and then tells it to actually flash. On good cameras, this happens really quickly...you can't see it happening. On bad cameras, the time delay between the pre-flash and the main flash is so long that people have time to shut their eyes after seeing the pre-flash! But soon things got more complex. Some idiot wanted to be able to include the "slave" flash(es) IN the TTL-auto loop. So manufacturers started sending out a coded message, after the pre-flash, but before the main flash. It's like this:

[click]...[buzz]...[ POW ]

With this system, the photographer can control the output of many "slave" flashes from the camera. Like make "slave" #1 a bit brighter than "slave" #2...and still have all the flashes under TTL control (thus, when the ambient light changes, the exposure is still "right").

These new click/buzz/POW flashes don't play nicely with the older varieties. The problem is that the [click] and [buzz] are bright enough to trigger the "slave" and [POW]...it goes off prematurely. There are some fancy, old flashes that have a filter for the relatively high-frequency [click] and [buzz], but most will not be that sophisticated.

The fancy, new click/buzz/POW flashes are smart enough to have different "channels" so that other photographers close by, who have the same click/buzz/POW flash system can each select a different "channel" to eliminate interference between each of their systems. But other users who have older systems can still be triggered by the [click] and [buzz]. :-(

Bottom Line: Get a Nikon system, learn to use their CLS, and look down your nose at other photographers w/ lesser systems. ;-)

Actually, don't do that last part!

--
Charlie Davis
Nikon 5700, Sony R1, Nikon D50, Nikon D300
HomePage: http://www.1derful.info
“...photography for and of itself – photographs taken
from the world as it is – are misunderstood as a
collection of random observations and lucky moments...
Paul Graham

 

[tenggiri10]

hi, need to know about the slave and master flash.

The "master" flash is in control of the "slave" flash(es).

is the strobe is a master?

Not sure what you mean?

There are many different configurations. The simplest and oldest is to have a photo-detector on each "slave" flash that fire it when the "master" flash goes off. Back in the good old days, there were no "slave" flashes...you bought a little adapter that you put a flash on...the adapter had the photo-detector to trigger the flash on top. Now-a-days, some flashes have photo-detectors built in...they work the same way, just more convenient...you just switch the flash to "slave" mode and voila'...

But there are more complex flashes too. Now-a-days, most flashes have a TTL-auto mode, where the flash emits a weak pre-flash and the camera looks at the exposure and computes how much light the flash must produce for the exposure, then sends a command to the flash and then tells it to actually flash. On good cameras, this happens really quickly...you can't see it happening. On bad cameras, the time delay between the pre-flash and the main flash is so long that people have time to shut their eyes after seeing the pre-flash! But soon things got more complex. Some idiot wanted to be able to include the "slave" flash(es) IN the TTL-auto loop. So manufacturers started sending out a coded message, after the pre-flash, but before the main flash. It's like this:

[click]...[buzz]...[ POW ]

With this system, the photographer can control the output of many "slave" flashes from the camera. Like make "slave" #1 a bit brighter than "slave" #2...and still have all the flashes under TTL control (thus, when the ambient light changes, the exposure is still "right").

These new click/buzz/POW flashes don't play nicely with the older varieties. The problem is that the [click] and [buzz] are bright enough to trigger the "slave" and [POW]...it goes off prematurely. There are some fancy, old flashes that have a filter for the relatively high-frequency [click] and [buzz], but most will not be that sophisticated.

The fancy, new click/buzz/POW flashes are smart enough to have different "channels" so that other photographers close by, who have the same click/buzz/POW flash system can each select a different "channel" to eliminate interference between each of their systems. But other users who have older systems can still be triggered by the [click] and [buzz]. :-(

Bottom Line: Get a Nikon system, learn to use their CLS, and look down your nose at other photographers w/ lesser systems. ;-)

Actually, don't do that last part!

--
Charlie Davis
Nikon 5700, Sony R1, Nikon D50, Nikon D300
HomePage: http://www.1derful.info
“...photography for and of itself – photographs taken
from the world as it is – are misunderstood as a
collection of random observations and lucky moments...
Paul Graham

what is the different between Canon 430EX and 580 EZ? I read, the 430ez can be a slave not a master.

 

[Mike_PEAT]

Similarly I shall continue to use the word "torch" for a hand-held device which emits a continuous light.

Then what do you call "a portable source of fire used as a source of light, usually a rod-shaped piece of wood with a rag soaked in pitch and/or some other flammable material?"

Unlike other regions which use the term "flash-light" for such a device. Having already used the term "flash-light" for a continuous light, I suppose it was inevitable that there was no word remaining for an actual flash light.

Early flashlights "ran on zinc–carbon batteries, which could not provide a steady electric current and required periodic 'rest' to continue functioning. Because these early flashlights also used energy-inefficient carbon-filament bulbs, "resting" occurred at short intervals. Consequently, they could be used only in brief flashes, hence the popular name flashlight."

Personally I always thought because there are flashlights that can both flash on & off, and light up steady.

 

[chuxter]

what is the different between Canon 430EX and 580 EZ? I read, the 430ez can be a slave not a master.

I'm not a Canon flash expert. The 430 doesn't put out as much light as the 580. The "Guide Number" is the way to tell (but be sure that the GN is being quoted the same for each unit...feet vs meters and the FL).

The 580 is also more "advanced"...it has more features.

I Googled " Canon 430EX vs 580EX " and found the following comparison at:

http://www.the-digital-picture.com/Reviews/Canon-430EX-Speedlite-Flash-Review.aspx

" One of the primary differences between the 430EX and the 580EX is the amount of light each can provide. The 430EX has a Guide Number of 141' (43 m) while the 580EX has a Guide Number of 190' (58 m) (both at 105mm). The 430EX is not under powered for many uses, but the 580EX's significant power advantage can become important when using a flash modifier such as an umbrella, softbox or diffuser - or bouncing light off a high ceiling. In addition to being more powerful, the 580EX allows 1/1 (full power) to 1/128 power in 1/3-stop increments while the 430EX allows power settings from 1/1 to 1/64 in more granular 1-stop increments.

" The other primary difference is that the 580EX can be used as a master to trigger remote Canon wireless slave flashes while the 430EX can only act as a slave flash. Any number of Canon 430EX, 420EX, 550EX and 580EX Speedlites can be combined as slave units but only the Canon 550EX and 580EX Speedlites can act as slave masters. In addition, the Canon Macro Ring Lite MR-14EX, Macro Twin Lite MT-24EX, or Speedlite Transmitter ST-E2 can be utilized used as wireless slave flash masters. Many people start out with a Canon Speedlite 430EX Flash (or started out with 420EX) and later move up to a 580EX. The 430EX can then be used as a remote flash. "

Google is your friend...

--
Charlie Davis
Nikon 5700, Sony R1, Nikon D50, Nikon D300
HomePage: http://www.1derful.info
“...photography for and of itself – photographs taken
from the world as it is – are misunderstood as a
collection of random observations and lucky moments...
Paul Graham

 

[tenggiri10]

thanks, i've learned something here

what is the different between Canon 430EX and 580 EZ? I read, the 430ez can be a slave not a master.

I'm not a Canon flash expert. The 430 doesn't put out as much light as the 580. The "Guide Number" is the way to tell (but be sure that the GN is being quoted the same for each unit...feet vs meters and the FL).

The 580 is also more "advanced"...it has more features.

I Googled " Canon 430EX vs 580EX " and found the following comparison at:

http://www.the-digital-picture.com/Reviews/Canon-430EX-Speedlite-Flash-Review.aspx

" One of the primary differences between the 430EX and the 580EX is the amount of light each can provide. The 430EX has a Guide Number of 141' (43 m) while the 580EX has a Guide Number of 190' (58 m) (both at 105mm). The 430EX is not under powered for many uses, but the 580EX's significant power advantage can become important when using a flash modifier such as an umbrella, softbox or diffuser - or bouncing light off a high ceiling. In addition to being more powerful, the 580EX allows 1/1 (full power) to 1/128 power in 1/3-stop increments while the 430EX allows power settings from 1/1 to 1/64 in more granular 1-stop increments.

" The other primary difference is that the 580EX can be used as a master to trigger remote Canon wireless slave flashes while the 430EX can only act as a slave flash. Any number of Canon 430EX, 420EX, 550EX and 580EX Speedlites can be combined as slave units but only the Canon 550EX and 580EX Speedlites can act as slave masters. In addition, the Canon Macro Ring Lite MR-14EX, Macro Twin Lite MT-24EX, or Speedlite Transmitter ST-E2 can be utilized used as wireless slave flash masters. Many people start out with a Canon Speedlite 430EX Flash (or started out with 420EX) and later move up to a 580EX. The 430EX can then be used as a remote flash. "

Google is your friend...

--
Charlie Davis
Nikon 5700, Sony R1, Nikon D50, Nikon D300
HomePage: http://www.1derful.info
“...photography for and of itself – photographs taken
from the world as it is – are misunderstood as a
collection of random observations and lucky moments...
Paul Graham