I tried this a year or two ago and had limited success due mainly to a poor optical slave that wasn't compatible with canon speedlights.
Having recently obtaining some second hand Multimax's at very reasonable prices, I thought it was time to give it another shot. I tried setting up a delay on the flash as suggested on a few web sites, Ian Hylands, Strobist etc.. I ended up getting it working with a delay of 0.0925 but could not get any consistency at all.. Some shots would completely miss and some partial frames, and varying exposure results...
I'm wondering if anyone else has had similar problems with 5DII and Multimax flash delay triggering ?
I'm using Broncolor Mobil lights so they are pretty long duration and would seem to be ideal for this 'crack'.
I got a little frustrated so decided to go back and try the optical slave idea because I bought a couple of slaves from the UK a month or two back and it works great.. Seems very consistant, no misfires and frame is always full even down to 7.0 on the mobil...
Who has tried this and how did you go ? Would you use this in commercial work ?
Here is the setup and a couple of shots.. sorry about background etc, I was concentrating on the mechanics first..
It's fine if you don't need much flash power because you are basically using your strobe as a continuous lightsource taking big hunks out of the flash. When I need fast sync it's usually because of bright ambient so an ND filter does the job better.
If you want to freeze water why not just use a speedlight? Mega fast flash duration.
Thanks Mark,
I agree with your summation here and was wondering if I was missing a point wtih this exercise... Even with a good size studio light, you loose too much power to be able to do much that is usefull, the best I could achive at full power was about F7.1 (1/8000) at about 1.2 meters. The hack does give you the ability to take ambient out but as pointed out, nothing that a speedlight can't do. (or my D-Lux which doesnt' have a shutter!)
I guess if I need or want to do anything substantial (other than freezing water or spinning wheels!) in the future, I will have to hire some really expensive lights because I can't afford to buy them yet.
Another thing that I saw doing this is that the 5DII has inconsistant lag times from shutter press to shutter starting to open. I guess we are talking 1/1000ths of a second but that can have an impact when trying to use 1/8000. It seems that by using the HSS hack, you are letting the camera tell the lights when it's ready to to open the shutter after all the electronic instructions have completed etc.. (By all reports, it seems that other cameras and brands also vary a bit)
As a Nikon user, this is easy to accomplish as the camera controls the flash sync and this can be tapped into using the body PC/hotshoe or even flash PC socket. With Canon it's a little more difficult as the flash controls HSS and not all flashes have the PC sync available making adding a radio to that pretty difficult - hence the slave cell in the diffuser. The 580II does have a PC sync so you should be able to sync from that reliably, although in the past there's been confusion surrounding just which sync port did exactly what with Canon. I questioned this to clarify on this forum in the past and there was a sort-of reply here which was inconclusive.. but I know that people have used the Flash PC socket for sync.. : https://www.fredmiranda.com/forum/topic/969272/1#9298649
I'm puzzled by the use of the delay on the Multimax as I expect that this relies on the regular x-sync point with the Multimax in the hotshoe? (Maybe not?) So why a delay - as there should be an advancement to obtain the HSS timing since this needs to occur at the beginning of the first shutter openning and not at the completion of the first shutter crossing the sensor?
If you were using the HSS sync timing, then it still doesn't make sense. There's already a delay introduced using the slave cell.. then the cable.. then the Multimax. These things need their delays reducing to get closer to the Canon sync point not extending.
I've tried quite a few studio flashes using Nikons and even the cheapest radio transmitters do this pretty well and there is not normally any loss in ratio to the exposure obtained when shooting at x-sync for those that work. For those that don't work - they JUST don't work.
Whether you could use this commercially would depend on your camera and flash. I would use it as a matter of course up to 1/8000s, and another photographer - specifically for water shots - previously said he'd use his Bowens Traveller G's using this tecnique rather than hire 'fast' strobes as he had done in the past, so I suppose it depends on what you need to achieve.
I've not tried using the PC port on the 580EXII, I've always thought it was to receive a trigger signal, not generate one. Edit: Guess you may have been talking about the PC port on the 5D, I'll give that a shot too.... Doh!"
Quoting from that article, "... some of you are probably thinking, "if you put a delay on the flashes and none on the camera then won't the flash fire after the camera?" and in a perfect world you'd be right. However the camera takes a lot longer to receive the signal and trip than the flash does. Cameras are mechanical and need to do a lot more than a flash does."
So basically, you are delaying the firing of the flash while the camera sorts out measurements, focus, and mechanical actions, then after a certain delay from when the shutter button was activated, the first curtain is ready to start opening and this is when the flash should fire. You can either do this with the delay feature on Multimax's or hacking the HSS which is triggered just before 1st curtain. (Sounds like on a Nikon it's easier). My coments on the Multimax were that this electonic and mechanical delay while the camera runs through it's pre-release instructions and mechanical actions is not exactly consistant 'shot to shot' and that makes the Multimax delay unreliable due to the variation in the actual delay. By letting the HSS feature tell us when the first curtain is ready to go, you avoid having to worry about the time from shutter press to first curtain.
I have found the 'peanut' optical slave very reliable so I'm happy for now but may give the PC port (converted to miniphone on my 580) a shot when I get some time.
I can see some uses for this hack but only if I don't need a lot of power. Dialing down the sun is a bit much to ask, but if I'm just looking for 1/8000 and don't need a lot of power, then it's a real option. So it may have some limited value in the future.
Trying to sync remote cameras and remote flash separately beyond x-sync consistently? Thats a big ask, I suggest you experiment with your PC sockets or your (now) miniphone port. Once you get this method down, just firing your remote camera (if indeed it needs to be remote) will be a cinch and everything will sync consistently.
All things compared, (generalising here) an optical slave is only as fast as a cable, compared to a fast radio these are both slow. The Multimax and PlusII's are slower than the ControlTL setup, I believe.. so it would make sense for better results to work your way up the speed chain ...now a slave cell and a sync cable together - I bet the delay might be measured in cm's - and might that be a double delay even ?!
...now a slave cell and a sync cable together - I bet the delay might be measured in cm's - and might that be a double delay even ?!