RF60 as Master
Good day everyone,
I have a Fuji X-T10, V6 II, RF60 and a Nikon SB700. Sometimes on events where there's a wall or ceiling to bounce I always put the flash on cam, and I'd like to try and use my SB700 to experiment some rim lighting.
I believe this set up should work just fine but I can't make it work.
X-T10 + RF60 as master on camera. Channel is correct and also for the group. RF60 is working properly as it is on the hotshoe.
V6 II + SB700- Flash profile set to Nikon SB700. Test button fires the SB700, set to TTL, also adjusts the zoom, but doesn't fire when I hit the shutter.
Turned power ON from top to down.
I don't know if there are other settings that i missed.
I have a Fuji X-T10, V6 II, RF60 and a Nikon SB700. Sometimes on events where there's a wall or ceiling to bounce I always put the flash on cam, and I'd like to try and use my SB700 to experiment some rim lighting.
I believe this set up should work just fine but I can't make it work.
X-T10 + RF60 as master on camera. Channel is correct and also for the group. RF60 is working properly as it is on the hotshoe.
V6 II + SB700- Flash profile set to Nikon SB700. Test button fires the SB700, set to TTL, also adjusts the zoom, but doesn't fire when I hit the shutter.
Turned power ON from top to down.
I don't know if there are other settings that i missed.
Comments
V6 II and X-T10 are working fine with RF60 as off camera flash even in HSS, although sometimes there are misfires and sometimes small black bars. But not always.
Actually this won't work.
Reason: A slave cannot be smarter than the master.
A V6 II set to RX mode needs digital information but it won’t get it from a RF60 in Master mode.
RF60 is like the V6, which uses analogue signal. But the V6 II uses digital signals. Only the V6 II can trigger RF60, because the V6 II is smarter so it can be a master, but not the other way around.
Instead of using the RF60 as Master, we would recommend putting a TTL flash (your SB-700) with TTL pass-through turned on the V6 II and triggering the RF60 as off-camera. Such a setup will support HSS.
Thank you and let us know if you have any questions or concerns.
Brand Manager
The RF60 does not have the hot-shoe contacts that would enable it to communicate with the camera.
If you want HSS with an RF60 then there is no way around the V6II.
BTW, personally I much prefer to only have a V6II on the camera, rather than a heavy and big RF60. The V6II also has more dedicated hardware controls for multiple flash control. So unless you really want on-camera flash as well then I think a V6II is a better controller anyhow.
As Class A mentioned, it's a hardware thing. And it would be a major change by plugging in a multi-system hot shoe from the V6 II, plus all the related hardware and software that goes with it.
The RF60 has a single pin hot shoe, and it works with the original V6 for remote flash power control, remote zoom control and remote firing. All works with the single hot shoe contact pin. But when it is triggered by the V6 II, the RF60 only works as a Slave / receiver mode.
Maybe an "RF70" would be able to do that?
No, we have nothing on the drawing board yet
Brand Manager
Technology. If we wait until the "perfect" model comes, we'll be waiting forever right? Have you folks got any sales for upcoming US Labor Day?
Brand Manager
It would seem that the RF60 is capable (in principle) of working as a master even for V6II receivers as long as it uses one of the latest firmware versions.
At least its test button can fire remote V6II Rx units. Currently, however this triggering does not work when the RF60 itself is triggered through its hot-shoe foot.
Potentially, all it takes is a fix of a software bug, to make the RF60 truly capable as a master for V6II receivers.
I don't think the camera can send any sync timing signal to the RF60 set to master via the single hot shoe pin on the flash?
Brand Manager
Regarding HSS triggering, it seems to me there are two main critical elements ...
1) The camera has to be able to send a trigger signal to a device on its hotshoe when the exposure time is shorter than the camera 'Max Sync Speed' ....
2) The device on the camera, the 'triggering device', has to be able to communicate to the HSS capable flash, what is the duration of the flash pulses required (ie what is the 'shutter speed').
As ClassA has said about the RF60, it is a Manual flash for these purposes, so (certainly on many cameras) can't perform No1 above, and its radio transceiver is a type that can't perform No2 either ....
The normal solution within the DSLR systems is the use of a TTL Dedicated System (proprietary) flash, as this allows the camera to both send the trigger signal and also the TTL pre-flashes will communicate the exposure time value to the Wireless Slave.
The nice new solution we now have with Cactus is the V6II, which as I understand it, has the electronics to make the camera 'think' there is a Dedicated System flash set to HSS mode on the camera, therefore allowing the trigger signal beyond the 'Max Sync 'Speed'. Also, I'm assuming, the V6II includes the contacts and digital communications to send the 'shutter speed' information to a receiving HSS flash (either one with a another V6II as receiver attached, or an RF60 with updated firmware) .... does that sound right?
It does raise one question which has been on my mind for some time now .... I have the original V6 and an RF60 flash, and for HSS I use the method of having a P-TTL (Pentax) system flash on the camera, and I use the Optical Slave and HSS Sympathy Modes on the RF60, receiving the optical trigger signal from the Pentax Flash.
BUT ... I have always wondered .... if the Dedicated System flashes need to use their Pre-Flashes to send coded shutter speed information to the system wireless slaves (in HSS mode), how can the RF60 'know' how long to illuminate for, given that it can't understand the Pre-Flash information ... it can only fire when it gets the optical trigger signal ?? So how does the RF60 know when to stop firing its HSS pulses if it doesn't have that (presumably needed) exposure time info from the triggering flash?
Or is the pre-flash information with Dedicated System flashes really only for exposure metering aspects (the shutter speed is a component for flash metering with HSS) ? Sorry, hope this is not too off-topic, just thought it might add to the interesting points already made in this thread!
Although the RF60 cannot read the camera's shutter speed, that isn't necessary to command V6II receivers at shutter speeds that do not exceed the sync-speed.
I am convinced that the RF60 -- with the right firmware -- is capable of sending the right radio signals to make the V6II receivers fire. As a matter of fact, it demonstrates that it can do so by how the test button functionality is implemented. That -- in contrast to hot-shoe triggering -- does trigger V6II receivers.
In summary, the RF60 -- with its single pin hot-shoe foot -- will never be an HSS master, but there is no reason why it shouldn't work as a standard master for the the V6II.
The RF60 does not need to know the shutter speed to perform HSS. The HSS burst duration is always the same: A bit longer than the sync-speed.
Exposing the full sensor always takes the same time, i.e., the time that is equivalent to the sync-speed of the camera. At higher shutter speeds, a slit formed by the shutter curtains travels over the sensor. All that changes for different shutter speeds beyond the sync-speed is the size of the slit. The curtains always travel with the same speed.
Hence the RF60 does not need to receive any information from a V6II regarding shutter speed.
Even a feature like rear-curtain sync, would not require the transmission of shutter speed, if the V6II does all the calculations and just sends a plain "fire" signal at the right time.
Summarising, P-TTL is implemented in a manner that requires the transmission of some camera-owned information to off-camera flashes through pre-flash control signals. However, it is not necessary to replicate the same scheme when using radio signals (for instance, power level changes are communicated as they are made, there is no need to delay them to a pre-flash period). As a result, the RF60 does not need any "pre-flash" information and does not even need to issue a pre-flash either which is good news for maximum power of a 1/1 flash, battery life, and subjects with super-fast eye-lid reflexes.
So I understand that the RF60 does not fire its HSS pulses for the specific exposure time, but just for a longer, fixed amount that 'covers it all' - literally.
I must question that point you made ClassA about exposing the full sensor ..... you say that this 'always takes the same time' .... ?? How can that be so? Surely it takes exactly the amount of time set by the 'shutter speed' control .... eg, a 1/180th sec exposure takes 1/180th second to fully expose the sensor .... 1/8000th exposure takes 1/8000 to expose the full sensor .... is that not right? They are very very different amounts of time.
What you say about the RF60 continuing to pulse for at least the max sync speed suggests that for most HSS exposures it will be wasting power, because the shorter exposures will be finished well before the RF60 stops providing light. My assumption about TTL flashes sending exposure time information to their HSS slaves is in order to remove any wasted power by ensuring the HSS pulses only last as long as needed ....
With your 1/180s example, you are correct.
With your 1/8000s example, you are wrong. Any given area on the sensor is only exposed for 1/8000s of a second, but to accomplish the exposure of all of the sensor takes ~1/180s.
You need to visualise a slit -- formed by the end of the first curtain and the beginning of the second curtain -- travelling over the sensor in a vertical movement. The slit is so small that it only exposes a given pixel for 1/8000s of a second. But the slit moves relatively slowly over the sensor so from start to finish, it takes about 1/180s to cover all of the vertical height of the sensor.
There are no focal plane shutter blades that could open and close so quickly to leave the full sensor area exposed simultaneously for just 1/8000s. Typically, the maximum speed available is 1/250s and faster speeds have to be realised by not simultaneously exposing the full sensor area, but by moving a slit over it.
BTW, this means you always get a bit of a "rolling shutter" effect with high shutter speeds. The bottom part of the frame is exposed at a different moment in time than the top part of the frame. With quick horizontal movement that can lead to skewing effects. If the whole picture would be taken at 1/8000s then you wouldn't see such skewing effects.
It is true that a lot of the flash's power is wasted as the light is hitting the shutter blades and only a small amount is allowed through the slit (wherever it happens to be).
However, this is true of all high shutter speed flash techniques (in conjunction with focal plane shutters). It manifests itself by the flash exposure becoming depended on shutter speed (something that isn't true as long as shutter speeds do not exceed the sync speed as a simultaneous exposure of the full sensor area at once is possible independently of how long the shutter stays open).
Even HyperSync (aka PowerSync, HiSync, etc.) techniques suffer from the same problem: The shutter blades reject a lot of the flash's light.
Even P-TTL flashes have to keep up their HSS bursts for a bit longer than 1/180s. No pre-flash communication can change that.
You will have noticed that you are getting a lot less flash power out of your P-TTL flash at 1/8000s than you are getting at 1/180s. The reason is that at 1/8000s a lot of the flash's output goes to waste.
So, really, beyond the max sync, the exposure time that is set on the camera is effectively controlling the gap between the 'curtains', and it is this gap that determines the amount of time that each pixel is exposed to light. The wider the gap then the longer the exposure of each pixel to the light .... 1/8000 - 1/4000 - 1/800 - 1/400 etc etc.
However, the amount of time it takes for the moving gap ('slit') to pass from top to bottom (or reverse) is actually fixed, and equal to the Max Sync speed of the camera. Therefore, in order to equally expose the whole sensor during HSS mode, the flash needs to keep pulsing for the full time the 'slit' is moving, equal to the max sync speed. .... does that sound right?
I'm thinking now, about the TTL flashes ..... obviously as you say they also have to work the same way as the RF60 in terms of exposing the whole sensor, so I guess the coded pre-flash information relating to 'shutter speed' does not control the amount of time the flash pulses for . So most likely then is that this information is used for automatic metering purposes ..... obviously again, the RF60 is not requiring that.
Yes, exactly.
I don't know exactly what information is encoded in the P-TTL communication pre-flashes, but for sure they include power level information (based on the camera's metering results and its own flash compensation setting), "wireless" channel information, and perhaps some timing information (when exactly to issue the main flash).