Wireless Flash Control

[mike_young1]

I recently received a Canon off camera flash cord and a Cactus wireless flash

remote control. I hooked up the off flash cord to my 5d and 580ex2 and all came

out as expected. I then removed the cord and installed the wireless remote.

Note at all times I was shooting in M mode and M mode on the flash. The shots I

took with the cable were ok but the shots taken with the remote have a black

stripe on the right side. I was shooting at 1/200 and f16. Note that the

picture data shows flash off for the shots taken with the remote. Can anyone

expain what happened and am I doing something wrong or is this just a feature

of a 35.00$ remote control?

tia mike<div></div>

[greg_moss2]

Looks like shutter sync issue. Try a slower shutter speed. The shutter sync speed usually has to be adjusted when you shoot wirless. It adds a little lag time.

[colinsouthern]

Cactus wireless products are absolute junk. Replace it with an ST-E2 and you'll not only cure you're issue as per the above, you'll also retain ETTL-II that you had via the OCSC.

[mike_young1]

If I get an ST-E2 which mounts on the camera hot shoe, do I need anything else for the Canon flash units such as a receiver or can they see the ST-E2 signal as is?

tia mike

[NK Guy]

You exceeded the camera's X-sync, which is the maximum shutter speed at which the camera

can synchronize with non-FP flash. The 5D can normally sync up to 1/200 sec, but not with

wireless, as mentioned above. It's not a matter of the Cactus product itself, which is mediocre

but not total junk.

 

The ST-E2 can command a 580EX II without additional hardware if you want, and it won't let

you go above the X-sync. Won't necessarily give you better results, but it will give you

automated metering.

[gerrymorgan]

<p>

As others have noted, the problem is the sync speed. It will probably sync OK at 1/160 or slower. If you have already set your flash to the lowest setting and can't reduce its power any more (in order to use a slower shutter speed), how about using a <a href="http://www.bhphotovideo.com/c/product/38380-REG/Norman_810551_ND_5_Neutral_Density_Pack.html">neutral density gel</a> to reduce the flash power. It would be much cheaper than buying an ST-E2.

</p>

<p>

To test this theory, you could try an even smaller aperture (ignoring, for this test, the fact that image quality will start to suffer from diffraction). Try 1/160 at f/18 or 1/125 at f/20. If that solves the sync problem, the gels could be the way to get the aperture you want at a speed your camera can sync at with cheap radio triggers.

</p>

[mike_young1]

Once again, thank you guys.

mike

[wilbur_wong]

I may be all wet here, but I thought that the 580 with a 5d was capable of high speed sync (the flash pulses repeated lightings continuously while the shutter "slit" passes in front of the film/sensor?

 

Maybe something needs to be set for "high speed synch", perhaps not achieveable with non Canon components.

[zigzag]

if you have the 5D then you should also be aware that the Cactus eBay triggers are known to be responsible for banding on the image (independent of this sync issue). This banding can be seen in dark areas of the photo and is probably due to RF interference. It doesn't happen all the time and it is known to be more prominent in units that have been modified with external antennae. I haven't noticed them on my 30D yet. Doesn't happen with PW's. As a 'junk' collector, I am about to buy a new Cactus receiver as they seem to work OK for non professional assignments (i.e. when your living doesn't depend on it.)

[colinsouthern]

Wilber Wong wrote:

 

"I may be all wet here, but I thought that the 580 with a 5d was capable of high speed sync (the flash pulses repeated lightings continuously while the shutter "slit" passes in front of the film/sensor? "

 

You can certainly command that from an ST-E2 (it has a dedicated button just for that purpose).

[NK Guy]

> Maybe something needs to be set for "high speed synch", perhaps not achieveable with non

Canon components.

 

That's correct. You get FP mode (high speed sync) with Canon E-TTL flash units, but not

when you trigger stuff generically this way.

[zigzag]

My experience tonight with the RF-04 and PT-04 eBay wireless triggers is that the max flash sync speed is indeed 1/160s - I get the same as you at 1/200s and worse at 1/250s. This is in contrast to the 1/250s flash sync speed obtainable by direct connection.<br><br>

 

Setting the Speedlite 580ex to HSS has no effect i.e. the shutter curtain effect is the same for the eBay gadget. Of course, the HSS allows fast syncing with a wired connection and (as Colin says) with the ST-E2.

[gerrymorgan]

By the way, I think it actually does make a difference whether you use a good wireless trigger or a cheap one. With my RF-04 and PT-04 eBay wireless triggers, the highest synch speed I can reliably get with my 20D is 1/200s, although 1/250s sometimes works. When I use Pocket Wizards (which cost more than ten times as much as the eBay triggers) my 20D reliably synchs at 1/250s.

[mats_vuorenjuuri1]

<p>I shoot mainly with canon flashes and use a 580 as a master flash. This way I can retain the high speed sync which is essential outdoors if I want to get sky detail. Also with higher sync speeds I need less flashpower because I can open up shutter. My problem is that canon IR system is unreliable outdoors especially in direct sunshine. I know about radiopoppers but cannot get them in europe. Has anyone experience of using The MiniTT1 Transmitter with canon flashes? Is high sync speed really available? This system is E-TTL but what I really need is the ability to adjust flashoutput of the slaves in manual mode from my camera as I can with the 580 EX as master?</p>