Paul C. Buff, Inc. Technical Forum

Hi,

I am wondering if it is possible to trigger a stock Einstein optically using the Canon ST-E2 across most settings. I was able to get it to work using a 24-70mm lens, but only at f2.8.

Thank you for any info or advice!


Steve

I don't know if the infrared signal from the ST-E2 would trigger the Einstein well, but you could definitely put your 430EX's in manual mode and trigger them with the ST-E2. Their flashes would trigger the Einstein's slave eye.

Depending on the Einstein's power setting you could also try TTL with the ST-E2. There will be a pre-flash from the 430's that will trigger the Einstein but it has such a short recycle time that it would probably still give you good output for the actual exposure unless it was on a higher power setting. The Einstein's flash wouldn't be considered by the TTL though, so you'd need to be lighting very distinct and separate regions with the Canons and the Einstein. You could light the backdrop with the Einstein and use Canons/TTL for a subject in the foreground, for example.

If you aren't using the 430's for the picture, just put one of them on your camera in place of the ST-E2 and set it to manual - a low power around 1/32 or 1/64 should be enough to trigger the Einstein's slave eye and generally would be too dim to contribute to the exposure. The camera's pop-up flash would also work like that.

The ST-E2 can certainly trigger the Einstein with the IR pulse (assuming line-of-sight). However, the pre-flash that is given by the transmitter (just like any other speedlite) will trigger the Einstein in sync with the preflash, but before the exposure flash. As stated above, if you have a low power setting on the E640, it may very well recycle fast enough to trigger again for exposure, but it may be too little light, or it may be correct amount of light. If you have a higher power setting, it will not flash again at all. In addition, if your speedlites are in TTL mode, the flash given by the E640 during the preflash will interfere with proper metering and exposure of the speedlites. Bottom line is yes it can trigger, and it may work in some cases, however, it will not be the most reliable means of doing so. Even if the speedlites are in Manual mode, some systems (I cannot speak in absolutes for Canon) will still trigger a preflash to establish a communication line between transmitter and reciever (ST-E2 and 430EX).

I have to correct TS on this. Pre flash usually precedes main exposure flash by only about 20msec. This is way too fast for Einstein to recycle, even at lowest power settings.

To recycle fully, quite likely. However, in previous tests, there is enough power to make good exposures at reasonable apertures, if you compensate for the lower power in the abbreviated recycling. Nonetheless, this is certainly not a method I would recommend. This is more to alert those who may have seen it work before, but not in another instance. There have been multiple customers call in who have used pop ups (or Speedlites, etc.) and did not know better, and all was well enough. Then when they needed more power, they would dial the power up, and no exposure. This could, of course, vary widely among camera models, even within the same brand.

Sorry for providing some misinformation above.

I did some tests tonight. I don't have an ST-E2, but I use a Canon 7D and it's on-camera flash can serve as a wireless master controller. I presume that the results would be similar with the ST-E2 but only a real-world test could confidently affirm that. I tried several settings to see which would allow an optically triggered Einstein to contribute to the exposure.

Using 7D as wireless master in ETTL and 580EX-II as wireless slave, the Einstein does NOT contribute to the exposure.

Using 7D as wireless master in Manual and 580EX-II as wireless slave, the Einstein does NOT contribute to the exposure.

Using 580EX-II on camera as a wireless master in ETTL and 580EX as wireless slave, the Einstein does NOT contribute to the exposure.

Using 580EX-II on camera as a wireless master in Manual and 580EX as wireless slave, the Einstein does NOT contribute to the exposure.

If I used a radio trigger on camera to fire an off camera 580EX-II in Manual mode, the Einstein DID contribute to the exposure.

Using the on-camera popup flash in Manual OR an on-camera Speedlite in Manual, the Einstein DID contribute to the exposure.

And strangely, using an on-camera Speedlite (or pop-up flash) in ETTL, the Einstein DID contribute to the exposure. Visually, it appeared to lose a small amount of power when fired this way. It metered higher because of the contribution of the Speedlite but I couldn't distinguish the exact contribution of each.

So in summary, using a Canon 7D or a Canon Speedlite as a wireless master controller, whether in ETTL or Manual, will NOT optically trigger an Einstein successfully.

You CAN trigger the Einstein with either the popup flash or an on-camera Speedlite if set in Manual, or with an off-camera Manual Speedlite fired by a radio trigger. (I was using the Phottix Strato 4-in-1.)

And for what it's worth, you CAN trigger the Einstein with an on-camera Speedlite (or even pop-up flash) in ETTL, but with some loss of power from the Einstein.

So it seems that the Einstein can recover enough from the pre-flash produced by simple ETTL to contribute meaningfully to the exposure, but it CANNOT recover from the pre-flash produced by ANY wireless master/slave combination I tried. And based on that, I really doubt that an ST-E2 would work with an Einstein since its infrared master signals would presumably be identical to those produced by the 7D or master Speedlite.

Not to be overly simplistic, but preflash = Einstein (or any other monoflash no-worky, no preflash = Einstein or any other monoflash worky.

Einstein can only fire once every 80msec (12fps) and will fire from the preflash and cannot fire again for 1/12 second . . . at extremely reduced power because it doesn't have time to recycle.

Thanks for all your answers. I also picked up this online:

Re using a ST-E2 to trigger monolights, the basic problem is that while the near IR output of the ST-E2 is quite sufficient to trigger the optical sensors on most studio flash heads, the studio flash systems mistake the initial transmission of control data that the ST-E2 sends out to the Slaves as the signal to fire. So when the camera body sends the “fire all Slaves” command out via the ST-E2, and releases the shutter, the studio slaves have already fired but not yet recycled enough to fire again. The result is an underexposed or black frame. The solution lies in something as simple as a small piece of paper. By inserting a piece of paper in the hotshoe as you slide the ST-E2 in place, you can cover the four side contacts, while leaving the center contact exposed. This has the effect of turning whatever is mounted on the hotshoe into a non-ETTL device. Indeed, it is the center contact that would be used to fire the studio strobes if your camera lacked a PC socket, and a hotshoe to PC adaptor was used. Similarly, it is the center contact that is used to fire any type of third party “dumb” flash unit, such as the famous Vivitar 283. Fortunately for us, the signal to “fire all Slaves” is transmitted to the ST-E2 via the center contact, and is in fact just a simple flash, disguised by the red filter on the front of the ST-E2. It may require a bit of fiddling to get the paper in just the right place, but once inserted, you will be rewarded with a really handy little optical trigger for virtually any studio flash system that supports optical slaving. Note that this also disables the AF assist lamp, so you will need to insure that there is sufficient light in the studio to allow for un-aided focusing.

So it seems like I can concurrently use an Einstein connected to the camera via a sync cord, along with an ST-E2 with my two 430EXs, but the ST-E2 alone will not allow me to trigger an Einstein and the speedlites. I am considering purchasing a CST Trigger Transmitter and CSXCV Transceiver Module to allow for wireless shooting. Believe this would be the proper pair for what I want to do.

Thanks again!

Steve

Two things to consider:

1. If you're getting a CSXCV, I'd really consider the Cyber Commander to fire it. It'll let you meter the Einstein and then adjust its power in terms of aperture instead of just watt-seconds. You can control every aspect of the Einstein remotely, even turn it on and off. I really like it.

2. Another product I really like is the Phottix Strato 4-in-1. It's a radio trigger that can also be used as a remote shutter release. (But not at the same time)

The reason it might be very useful for you is that it has a feature called TTL pass through. You put the transmitter in your camera's hot shoe, and then it has a hot shoe on top of it where you can put a Speedlite or your ST-E2.

So you could use the Phottix to trigger your Einstein and still use the ST-E2 on top to fire your Speedlites - even in TTL though you'd need to set your lights up thoughtfully for TTL to be helpful. (Wouldn't want to light the same thing with TTL lights and the Einstein or it'll wind up overexposed.)

You could also trigger the Speedlites with the Phottix (receiver has a hot shoe in addition to several cables for syncing to PC port, monolights, etc.) and then trigger the Einstein optically from the Speedlites' flash. THIS DOES "WORKY" - I just did it the other night. But of course, you'd be manual with the Speedlites if triggered by the Phottix. It has TTL pass through on the transmitter like I mentioned but it doesn't actually broadcast TTL through the air the way Radio Poppers do.

The only downside to the Phottix is that you have to buy it direct from China so it takes about two weeks to get them. I got two and have been very pleased. If you check it out, be sure you're looking at the "Strato 4-in-1." I think they had an older product just called the Strato that had less functionality.

UPDATE: I was unable to replicate concurrently using an Einstein connected to the camera via a sync cord, along with an ST-E2 and two 430EXs. Only the Einstein would fire. Looks like I really need another wireless solution. Thanks for your suggestions.

Steve