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06-17-2019, 04:33 AM   #1
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Normal HSS vs Powersync on RF60x

I think I've only ever used HSS in Normal mode with my V6ii and RF60x. Admittedly I haven't looked that much into it, but I read a blurb where it said something along the lines of using Normal HSS when you need shutter speeds up to 1/8000 and Powersync to be used for "extreme conditions where Normal HSS is not powerful enough."

What does that really mean? It makes it sound like I can use my flash at a stronger level than 1/1 max power in manual mode during HSS conditions

Cheers,

BB

06-17-2019, 07:43 AM   #2
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I think it works as one longer than exposure time flash with 100% power rather than burst of few quick flashes of normal HSS between the courtains when powersynced. I have RF60x but never had any need to use it.
06-17-2019, 07:46 AM   #3
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QuoteOriginally posted by BruceBanner Quote
What does that really mean? It makes it sound like I can use my flash at a stronger level than 1/1 max power in manual mode during HSS conditions
Never used the PowerSync mode myself, but my understanding is that it fires the flashes in full (1/1) mode only and that you can adjust the flash firing time to try and eliminate black banding. So not a HSS mode at all.

You cannot get more than 1/1 power out of the flash. Do not forget that HSS mode itself cuts the power output significantly because it pulses the light.
06-17-2019, 08:52 AM   #4
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Hello,

You can find very good definitions about what is powersync over there (ex. here Understanding HyperSync and High Speed Sync - PocketWizard Wiki). Sometimes it is called hypersync (I think they are exactly the same concept).

In powersync mode you fire your flash an maximum power and sync flash and camera so when your fire, and your first & second curtains are traveling over your sensor, you have light coming from the pulse of your flash, so all the frame is illuminated. You need a long pulse to achieve this, to 'cover' all the event. WIth HSS you emit a kind of continuous light during the same event. So you have two ways to get your frame illuminated, a long pulse or a semi-continuous light. Please, refer to the above link, and you'll find everything better explained.


Comparing a shot done with Powersync vs HSS, you get more light with powersync, but I'm afraid the difference will depend on the flash. With my Godox flashes I don't see so much difference, but it's noticeable. Sometimes you can get a pulse long enought without going to 1/1. Another point to consider is that, if you usually need to fire your flash at maximum power in HSS mode, HSS stresses more the flash compared with normal mode, so maybe is a better idea to use powersync instead of HSS.

I have no idea of how to get powersync on the RF60x, I can get powersync with my Godox flashes at 1/1 or a bit less, using some tricks or with old flashes where I can enable or disable HSS manually. Also, with my V6II I can get powersync with third party flashes if I put them at full power, easily.

Regards.

06-17-2019, 11:18 PM   #5
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Thanks everyone, it was this blurb about the RF60x that I saw the Powersync and it made me think "hmm... yeah... I should really get to know that setting/feature and what it does, see if it can help me out more" etc.

Cactus RF60X Wireless Flash | Cactus

I have shot a couple of events where I am using HSS and aiming straight into the sun (so that the subjects get rim lighting). What I found is that I really had to use my FA43 and not my FA77 for a lot of these kind of shots as one RF60x set to max power in HSS mode was not quite reaching the subject adequately (through my modifier set up) from the distance I was back from them. I had to switch to the FA43 and get in closer.

I was perplexed by this mode as I was in Manual power 1/1 in HSS situations and like pschlute says I didn't think I could get more power than that, but that blurb does seem to suggest otherwise... or is it just a weird thing whereby it senses the scenario and throws it into 1/1 for you (and therefore really no different to the results I was getting on the day being in Normal HSS).

Next sunny day I'll get my mannequin out in the garden and do some more tests. I can see that the V6ii has that setting for Powersync, but I'm unsure if I need to do something with my RF60x unit to make it work or whether that is enough.
06-18-2019, 12:37 AM   #6
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QuoteOriginally posted by BruceBanner Quote
I was perplexed by this mode as I was in Manual power 1/1 in HSS situations and like pschlute says I didn't think I could get more power than that, but that blurb does seem to suggest otherwise
Bruce, full power on that flash is 1/1 in a Non-HSS mode. Once you switch to HSS you are reducing your power significantly because the flash has to pulse. Switch to Powersync and your power is back up to 1/1 (maximum power), but you will get banding.

that is why the blurb suggests you get more power than in HSS mode.... because you will.
06-18-2019, 12:43 AM   #7
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QuoteOriginally posted by pschlute Quote
Bruce, full power on that flash is 1/1 in a Non-HSS mode. Once you switch to HSS you are reducing your power significantly because the flash has to pulse. Switch to Powersync and your power is back up to 1/1 (maximum power), but you will get banding.

that is why the blurb suggests you get more power than in HSS mode.... because you will.
Yeah I get that, like I mean 1/1 power is max output but under different shutter speeds it will vary in intensity in terms of reaching target etc. But like... why would they offer an option like Power sync (which is still apparently something that works over 1/200 speeds etc) that causes banding That makes little sense to me.

06-18-2019, 04:03 AM   #8
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Power sync mode with the V6ii is to allow you to use non HSS flashes beyond max sync speed..... A poor man's HSS!

But as already explained by the others, in certain configerations and set ups it will produce more output, although with possible banding or uneven coverage.

It is a function of the radio triggers, not the flash. By definition there is no power control in the mode, as it automatically sets max power..... The flash level is controlled using other parameters, ie aperture, ISO and distance. Therfore it is not as convenient or easily manageable as HSS.

There's not much point to it when using an HSS system IMO..... You've got a V6ii and RF60x, so you're not a poor man!!

Last edited by mcgregni; 06-18-2019 at 04:09 AM.
06-18-2019, 05:21 AM   #9
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QuoteOriginally posted by mcgregni Quote
Power sync mode with the V6ii is to allow you to use non HSS flashes beyond max sync speed..... A poor man's HSS!

But as already explained by the others, in certain configerations and set ups it will produce more output, although with possible banding or uneven coverage.

It is a function of the radio triggers, not the flash. By definition there is no power control in the mode, as it automatically sets max power..... The flash level is controlled using other parameters, ie aperture, ISO and distance. Therfore it is not as convenient or easily manageable as HSS.

There's not much point to it when using an HSS system IMO..... You've got a V6ii and RF60x, so you're not a poor man!!
Well I've been looking a little into this and there seems to be quite a bit of merit to it's use, I think possibly a very underrated feature seldom talked about. I need to study some more and practice this but I just tried it in my house now (as its night time here), and first off being in Powersync didn't trigger the RF60x at all I had to hit the Multi/HSS button which then activated, then I gave it a shot at 1/1000. Holy moly... man it was a savage burst of light!

Why I think this might be important to me?

I'm sure you've seen these examples before but all these shots here were fired in HSS conditions, broad daylight, sun behind subject, full power manual mode;

1/3200/2.2


1/3200/2.2


1/2000/2.2


These are nice shots, but through the soft modifier set up I was using I was forced to use the FA43 for these portrait shots, using the FA77 resulted in too little light reaching the target from where I was holding the flash and standing back from the subject for optimum framing. Sadly the FA77 saw little action that day.

If I could generate a shot under these conditions which resulted in greater power reaching the target then that would be great, it might allow the use of the FA77 to come out and play, and for me to consider other types of modifiers.

I've resisted going down the Godox Xpro-P + AD200 route because of cost, bulk (both the trigger and unit are larger and more awkward to stow away than the V6ii/RF60x), there are a couple of other reasons the Cactus have a pro over the con (that I won't get into here), but basically if there is a possibilty of a stronger pulse even if it is not completely even, I'm interested to know how that translates to shots like this.

---------- Post added 06-18-19 at 10:54 PM ----------


I mean I think I understand the basics of this;

Normal flash stuff, when you can't get past 1/200 or 1/250th or whatever the camera maxes out at, the flash burst is quick, 'Bam!' 1/13,000th etc. I guess you see this in the extreme with slow sync stuff, the flash freezes what it touches, the shutter is still to complete and thus you get some motion blur in the parts where the flash didn't freeze. At higher shutter speeds (1/200th etc) that motion blur is less noticeable.

In HSS the flash is weaker because it's going 'pew pew pew!' in that seemingly singular flash burst, but its actually rapid (literally strobbing) effect and due to that (for technical reasons) its weak. So although we can shoot at wide apertures and fast shutter speeds, when passing a speedlight through various modifiers to make the falloff better, it sucks in range.

Hypersync is like a prolonged amount of flash being fired. It lasts 1/300th of a second instead of the 'Bam' 1/13,000th. So now it's a case of 'KABOOMMMMmmmm' and because although there is only a little slit in the shutter visible during that high shutter speed shot (1/3000th etc), the flash is lasting longer (1/300th) so that the shutter speed doesn't matter so much, the subject is still caked in light head to toe throughout the shot.

I can now understand this guys rationale for thinking Hypersync (or Powersync as Cactus calls it) is 'Godlike' because it theoretically it's basically HSS shooting conditions but with proper power now once again.

People... why do we not talk about this at all. How long have I been on this forum talking about flashes and power and HSS issues and various modifiers... Does the end result be so bad? Is the banding utterly horrendous and light fall off so bad? I mean all my portrait shots get some vignette treatment anyway lol, I just have to work on one edge perhaps instead

Looking forward to testing this out, and probably being disappointed, but if not... umm... this is gold dust!
06-18-2019, 07:53 AM   #10
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i think you need to also factor in the longevity factor.

A flash that is outputting that amount of light over an extended time frame is going to get very hot very quickly.
06-18-2019, 10:20 AM   #11
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There is something odd about the implications of the above remarks -- that Hypersync is just as illuminating (lumens/meter squared) on the focal plane as a normal 1/1 flash. If the speedlight flashtube can normally flash in 1/13000 second (77 microseconds) and hyper flash in the 1/200 second (5000 microseconds) shutter sweep time for no banding, then the flash luminosity during the 5000 microseconds has to be 77/5000 as bright. (See next paragraph.) The film or focal plane array flash integration time, however, increases from 77 microseconds to the equivalent shutter time of the moving shutter gap, which we also take from Bruce's comment to be 1/3000 second or 333 microseconds. Hence the effective flash illumination is not 1/1, but (333/77)*(77/5000) = 1/15 if the flash total output (lumen-seconds) is the same for the two cases.

The flash unit only stores short term flash energy in its capacitor, which is not recharged to any practical extent during the flash time. Total energy stored in the capacitor is (1/2)CV^2 (farads, volts, joules). To a rough approximation, energy of the charge (joules or watt-seconds) is converted to photometric light energy (lumen-seconds) at a constant ratio. If, over the shutter sweep period of 1/200 seconds, the luminosity of the flash were constant, and at the same level as a normal 1/1 flash lasting 77 microseconds, then the capacitor energy used would have to be 5000/77 joules larger (65X) than for a normal 1/1 flash. This would require increasing the voltage by a factor of 8, or building the flash with a greatly oversized capacitor so that only a small part of its charge was used for a 1/1 flash. But speedlights are designed to use most of the capacitor energy at 1/1 to allow the capacitor to fit. Hence, I suggest that the hypersync mode imposes less subject illumination and corresponding focal plane illumination within the shutter determined duration as evaluated in the paragraph above.

The question then arises: What benefit can hypersync have over the rapid pulsed HSS. In my view the answer is that HSS by its nature conserves capacitor energy by rapid flashing and quenching. If this pulsed luminance is instead filled in to be continuous, then there is some inverse of the duty cycle gain in illuminance during the effective shutter gap period at the expense of flash heating or flash recovery time. Perhaps the flash uses the same control on/off period for HSS whether the overall shutter time on a camera is 1/300, 1/200, or 1/60 of a second, and has to be limited in ON time per pulse to meet the worst case duration. In other words, if the flash knew all of the camera shutter parameters applicable to the next shot, it could tailor its HSS output waveform to exactly deplete its capacitor when both shutter curtains were finished. In that case, it should equal hypersync in integrated illumination. Correspondingly, the camera would have to receive the flash waveform "plan" from the flash to scale its other exposure parameters from the P-TTL test flash results.

Supplementing HSS with hypersync is a way to boost illuminance without all the complexity of trying to maximize the HSS waveform. Note, however, that as the capacitor is depleted, the flash brightness drops, so hypersync might be expected to introduce a gradient across the parts of the scene that one is illuminating. This might also be expected with HSS, but could be corrected by proportional increases in the ON-time duty cycle.

Last edited by kaseki; 06-18-2019 at 11:32 AM.
06-18-2019, 11:56 AM   #12
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QuoteOriginally posted by mcgregni Quote
Power sync mode with the V6ii is to allow you to use non HSS flashes beyond max sync speed..... A poor man's HSS!
This ^ ^ ^.

I have done the same thing with my Yongnuo 560III speedlights at full power, optically triggered by my Sigma EF-610 EX as a minor contributor. It works like a charm since the discharge time is just a smidge longer than the slit dwell in the frame.


Steve
06-18-2019, 01:40 PM   #13
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QuoteOriginally posted by pschlute Quote
i think you need to also factor in the longevity factor.

A flash that is outputting that amount of light over an extended time frame is going to get very hot very quickly.
Correct, this thought had not escaped me, here's hoping that the RF60x cooling mode actually does it's job and prevents overheating. I'm curious to know how recharge cycle times are affected also. I think if you take the necessary precautions it should be fine. For my intended use it would be firing the flash 4-6x for a portrait shot, then giving it a rest for a few minutes before repeating again. Hopefully the speedlight can cope with that.

QuoteOriginally posted by kaseki Quote
There is something odd about the implications of the above remarks -- that Hypersync is just as illuminating (lumens/meter squared) on the focal plane as a normal 1/1 flash. If the speedlight flashtube can normally flash in 1/13000 second (77 microseconds) and hyper flash in the 1/200 second (5000 microseconds) shutter sweep time for no banding, then the flash luminosity during the 5000 microseconds has to be 77/5000 as bright. (See next paragraph.) The film or focal plane array flash integration time, however, increases from 77 microseconds to the equivalent shutter time of the moving shutter gap, which we also take from Bruce's comment to be 1/3000 second or 333 microseconds. Hence the effective flash illumination is not 1/1, but (333/77)*(77/5000) = 1/15 if the flash total output (lumen-seconds) is the same for the two cases.

The flash unit only stores short term flash energy in its capacitor, which is not recharged to any practical extent during the flash time. Total energy stored in the capacitor is (1/2)CV^2 (farads, volts, joules). To a rough approximation, energy of the charge (joules or watt-seconds) is converted to photometric light energy (lumen-seconds) at a constant ratio. If, over the shutter sweep period of 1/200 seconds, the luminosity of the flash were constant, and at the same level as a normal 1/1 flash lasting 77 microseconds, then the capacitor energy used would have to be 5000/77 joules larger (65X) than for a normal 1/1 flash. This would require increasing the voltage by a factor of 8, or building the flash with a greatly oversized capacitor so that only a small part of its charge was used for a 1/1 flash. But speedlights are designed to use most of the capacitor energy at 1/1 to allow the capacitor to fit. Hence, I suggest that the hypersync mode imposes less subject illumination and corresponding focal plane illumination within the shutter determined duration as evaluated in the paragraph above.

The question then arises: What benefit can hypersync have over the rapid pulsed HSS. In my view the answer is that HSS by its nature conserves capacitor energy by rapid flashing and quenching. If this pulsed luminance is instead filled in to be continuous, then there is some inverse of the duty cycle gain in illuminance during the effective shutter gap period at the expense of flash heating or flash recovery time. Perhaps the flash uses the same control on/off period for HSS whether the overall shutter time on a camera is 1/300, 1/200, or 1/60 of a second, and has to be limited in ON time per pulse to meet the worst case duration. In other words, if the flash knew all of the camera shutter parameters applicable to the next shot, it could tailor its HSS output waveform to exactly deplete its capacitor when both shutter curtains were finished. In that case, it should equal hypersync in integrated illumination. Correspondingly, the camera would have to receive the flash waveform "plan" from the flash to scale its other exposure parameters from the P-TTL test flash results.

Supplementing HSS with hypersync is a way to boost illuminance without all the complexity of trying to maximize the HSS waveform. Note, however, that as the capacitor is depleted, the flash brightness drops, so hypersync might be expected to introduce a gradient across the parts of the scene that one is illuminating. This might also be expected with HSS, but could be corrected by proportional increases in the ON-time duty cycle.
This video here talks about gradient and shows you some examples


It does seem to vary from trigger to trigger, but some are really acceptable.

From what I am understanding is that everyone seems so gung ho about HSS, but it does kinda suck lol. Maybe everyone is happy to shoot a speedlight at wide apertures bare and are happy with the results, but for others (me) I rarely want to do that, I want diffusion, and then that means additional loss of power to making HSS become incredibly difficult and close quarters work. It limits lens choice and such as well.


QuoteOriginally posted by stevebrot Quote
This ^ ^ ^.

I have done the same thing with my Yongnuo 560III speedlights at full power, optically triggered by my Sigma EF-610 EX as a minor contributor. It works like a charm since the discharge time is just a smidge longer than the slit dwell in the frame.


Steve
Hypersync is a poor mans HSS? Or is HSS the poor mans Hypersync?
06-18-2019, 03:22 PM   #14
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Last week I tested my Cactus flashes in HSS. I lost about 3 1/2 stops of power when I moved past max sync on my K3II. Some have said you would get banding but Cactus flashes can be manually adjusted to prevent this from happening. Advantage of Powersync = you can get full power. Disadvantage harder on the flash. Use HSS if it provides enough power, Powersync if you need a little more power (but max output will never exceed 1/1)
Regards

Update
Another tidbit MOTION if you shoot at or under max sync speed and expose subject mainly by flash the subject will be frozen by the duration of flash (very fast say 1/10,000 sec or so) When you go over max sync say 1/200 the flash will be creating light for that long and motion blur may be introduced. Sample take a photo of a golfers swing at MSS and you'll mostly freeze the swing. Now take the same shot @ 1/300 and you'll have a lot more motion blur.

Last edited by Photobill; 06-18-2019 at 03:44 PM.
06-18-2019, 03:38 PM   #15
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QuoteOriginally posted by Photobill Quote
Last week I tested my Cactus flashes in HSS. I lost about 3 1/2 stops of power when I moved past max sync on my K3II. Some have said you would get banding but Cactus flashes can be manually adjusted to prevent this from happening. Advantage of Powersync = you can get full power. Disadvantage harder on the flash. Use HSS if it provides enough power, Powersync if you need a little more power (but max output will never exceed 1/1)
Regards
Yeah, this was never about getting MORE power than what the flash can do, this was about getting more power at speeds above X-Sync. HSS does suck big time for power drop offs.

Typically, through my diffusion panels and set up for HSS outdoor work (I do live in sunny bright Australia remember, massive dynamic sunlight conditions etc), I don't even bother messing with power settings, I'm at 1/1 Power always. I also get restricted to lens choice (if hand holding the flash/softbox) due to fall off. Powersync could change that, allow me to use longer tele lenses further back, heck even use better diffusion properties!
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