Elinchrom Ranger high speed sync

Hi all,

I have an Elinchrom Ranger RX Quadra Async and two Quadra A-heads. Dong lots of reading on high speed sync and from what I see the head should be able to handle up to 1/6000. but when I go over 1/250 on the camera it starts to crop.

Now I know there are Quadra HS heads available but thought from the blurbs I'm reading the one I have should be fine. I cant see a setting on the pack for HS but..

Any help would be great, dont really want to spend another $600 on a HS head is what I have does it and its just me.

Hi, I've not used those specific systems, but since there are no responses yet, I'll make some educated guesses.

First, I presume that your camera uses a "focal plane shutter" which, at higher shutter speeds, essentially becomes a slit crossing the imager (film or sensor). The second "curtain" begins to cover the imager BEFORE the first curtain has gotten all the way across. Meaning that the entire imager only gets completely uncovered when shutter speed is set to the "sync speed" or longer exposures.

Generally speaking, an electronic flash, at least for the majority of the light output, is "faster" than this sort of mechanical shutter. So, if the imager is not fully uncovered when the flash fires, you will likely get a "shadow band," which I think is what is happening to you.

There are basically two ways to deal with this, given the limitations of your shutter. One can be done by some "hot shoe flashes," basically they can "fire" multiple times during the exposure, so it appears as almost continuous light during the shutter travel. The other method is to make the flash duration longer.

From looking through some of the Elinchrome online information, it looks like the "A" heads are specifically designed for the fastest energy-dump through the light head, meaning a short flash duration. So these would be really useful for freezing motion in relatively dim light, where even a fairly long shutter time doesn't add much to the exposure. But outdoors, in bright daylight, it's a different situation. In this case, when you are limited by the focal plane shutter's sync speed, it seems preferable to have a "long duration flash," lasting as long as it takes the shutter slit to cross the imager, and then actually use a fast shutter speed to freeze motion. You will not get full use of the flash's power at faster shutter speeds, but at least the scheme works. Anyway, the "HS" light head seems designed to make the flash pack's energy-dump take longer.

So my take on this is that you probably need to go to "HS" light heads in order to use shutter speeds faster than the sync speed. But... it still might not be enough; I dunno.

I'm getting my info from this page: WHAT HEAD FOR YOUR ELB 400

Near the bottom is a table comparing nominal flash durations using each head plugged into an ELB400. At full power the "A" head seems to have 1/2880 second duration, whereas the "HS" head seems to go for 1/550 second, roughly 5 times longer. At least that's how I interpret it - they have not labeled it as "seconds," nor do they specify the rating basis (typically they are rated as either t.5 or t.1; time to either 5/10 or 1/10 light "strength"). Personally I would want a clarification from Elinchrome, or perhaps try it with a demo or rental unit. I would also expect the light strength to be falling off over time, although perhaps Elinchrome has found a way to deal with this.

As a note, these shutter speed sync issues don't exist in leaf shutters; something to keep in mind should you ever be considering different cameras.

HSS, or FP (Focal Plane) synch to give it its more correct name, is a function of the camera, not the flash.

Standard synch (X-synch) fires the flash just as the first shutter blind gets fully open, and requires a shutter speed that makes the 'slit' between blinds equal to or greater than the width of the frame. This varies anywhere from typically 1/60th second with MF film cameras to 1/320th or even 1/500th with modern DSLRs. ( Use of radio triggers introduces a delay and usually requires the next slower speed to be selected. )

OTOH, true FP synch fires the flash just as the first blind starts its travel, and requires that the flash duration is at least equal to the transit time of the shutter.

On most (all?) DSLRs there is no way to manually force the camera into FP synch mode. They'll only switch to FP synch if an FP or HSS compatible speedlight or trigger gizmo is fitted into the hotshoe and the shutter speed is set higher than the maximum X-synch speed.

Once the camera is forced into FP synch mode, almost any old flash can be used at full power. The full power duration of most speedlights and studio flashes is 4 to 5 milliseconds, and this is sufficient to cover the shutter travel time of most modern DSLRs. There may be a slight drop in exposure across the frame as the flash decays from full brightness, but this is usually fairly unnoticeable.

Another method of getting FP synch requires a special radio trigger transmitter in the camera hotshoe. This uses the TTL pre-flash signal from the camera to time a false flash trigger signal that - roughly - coincides with the opening of the camera shutter. Such systems usually need fine-tuning to each camera to work properly.

PS. Above are oscilloscope traces of typical speedlight outputs at full power and in 'HSS' mode.