5D II controlling a Cactus V2s

oakfieldphotography.com

Hi all
I have just recently bought a second hand Cactus V2s. It did not come with any instructions but all i want to know is can i control the intensity of the off camera flash in my camera settings. All the trigger wants to do is output a full flash every time i take a picture no matter what mode i am in. I am using a Canon 5 D mkII and a canon 580ex2 speedlite.
Kind regards
Patrick.:dunno

ziggy53

I believe that the Gadget Infinity "Cactus V2s", the second generation of the Cactus V2, uses simple trigger sync via a single contact and ground on the transmitter and receiver. If you turn the transmitter over, the transmitter is the portion that attaches to the camera, you should see the single pin contact.

This means that you need to set the flash to Manual mode and manual operation. You may set the flash output via the flash user interface and menu system. All the camera provides is a simple synchronizing pulse when the contributing flash is needed. You are still limited to flash sync shutter speeds (1/200th on the Canon 5D MKII and Rebel series, and 1/250th on most other Canon bodies) and I recommend using Manual mode on the camera as well.

Since the signal is a simple radio sync pulse, there is no automation, including no remote settings control from the camera to the flash.

Edit: I believe that the Canon 580EX II also has an "Auto" flash mode, where the flash will automatically control output without using camera/TTL technology. This mode uses an older thyrister and sensor technology, which may or may not be appropriate for your situation, but at least it allows the flash some power automation without connection to the camera. You may wish to try this mode, but be aware that it depends on an "average" scene to be close to accurate and subjects and scenes which are not "average" may produce over and under exposed images, respectively.

oakfieldphotography.com

ziggy53 wrote: »

I believe that the Gadget Infinity "Cactus V2s", the second generation of the Cactus V2, uses simple trigger sync via a single contact and ground on the transmitter and receiver. If you turn the transmitter over, the transmitter is the portion that attaches to the camera, you should see the single pin contact.

This means that you need to set the flash to Manual mode and manual operation. You may set the flash output via the flash user interface and menu system. All the camera provides is a simple synchronizing pulse when the contributing flash is needed. You are still limited to flash sync shutter speeds (1/200th on the Canon 5D MKII and Rebel series, and 1/250th on most other Canon bodies) and I recommend using Manual mode on the camera as well.

Since the signal is a simple radio sync pulse, there is no automation, including no remote settings control from the camera to the flash.

Edit: I believe that the Canon 580EX II also has an "Auto" flash mode, where the flash will automatically control output without using camera/TTL technology. This mode uses an older thyrister and sensor technology, which may or may not be appropriate for your situation, but at least it allows the flash some power automation without connection to the camera. You may wish to try this mode, but be aware that it depends on an "average" scene to be close to accurate and subjects and scenes which are not "average" may produce over and under exposed images, respectively.

Hi Ziggy
I just tried out your solution and it looks like i will have to control the flash manually. Would a sync cord between the flash unit be a better option?
Kind regards
Patrick.

Moving Pictures

Just an aside - don't old-style flashes sometimes present too much voltage at the shoe for modern cameras to handle? I don't know if that affects synch cords ...

I've just delved into radio triggers (I used to do some optical stuff, back in the day), and I love 'em. Won't go back ... and, to be honest, I'm using the 580EX in its on-camera ETTL mode less and less ...

ziggy53

oakfieldphotography.com wrote: »

Hi Ziggy
I just tried out your solution and it looks like i will have to control the flash manually. Would a sync cord between the flash unit be a better option?
Kind regards
Patrick.

I only use off-camera cords for the flash when it is on a flash bracket. (That allows re-positioning the flash to keep it above the lens in either portrait or landscape orientation.)

To quote myself from my response to you last April:

http://www.dgrin.com/showpost.php?p=1599504&postcount=2

ziggy53 wrote: »

... The most comprehensive solutions are very expensive and can get a little complicated, and the simpler, cheaper solutions don't cover as many situations and uses.

To get a flash a little off camera you can use a simple sync cord or a more expensive E-TTL off-camera cord. The simple sync cord will work with a flash in manual or auto mode, but an E-TTL off-camera cord can give full flash automation from the camera.

If you want to go wireless there are both optical and radio transmitter-slaves that can work.

The optical systems, again, are either simple slaves from an externally mounted manual flash, or you can get digital slaves that will work with a pre-flash TTL external flash (or even from the built-in 40D flash.) In these cases you would set your 580EX II in either manual or auto mode.

If you want full E-TTL II flash automation you can use an external flash with wireless master capabilities, and another remote flash with wireless slave capabilities. Your 580EX II could be the master and an EX 430 the slave, for instance. You could also use a Sigma EF 610 DG Super flash as master and your 580EX II as slave. You could use a Canon ST-E2 wireless transmitter on the camera, but the Sigma flash only costs a little more, and you can still use the Sigma as a flash.

For radio, again you can have a simple master and slave system and use your 580EX II in either manual or auto mode. Or you can get radio flash control systems that support full E-TTL automation, but they are fairly pricey.

ziggy53

Moving Pictures wrote: »

Just an aside - don't old-style flashes sometimes present too much voltage at the shoe for modern cameras to handle? I don't know if that affects synch cords ...

No, his Canon 580EX II is already voltage safe and an off-camera cord would only reduce the voltage through resistance. It is perfectly safe to use off-camera cords with otherwise safe flashes.

oakfieldphotography.com

Thankyou Ziggy
forgive me for my loss of memory.
Kind regards
Patrick.

Moving Pictures

ziggy53 wrote: »

No, his Canon 580EX II is already voltage safe and an off-camera cord would only reduce the voltage through resistance. It is perfectly safe to use off-camera cords with otherwise safe flashes.

I goofed: I know the 580EX is good, I thought the Cactus V2 was an old-style flash, not a trigger.

Serve me right for posting from work, I guess.