[morenjavi]

I thought the same but you'll note that in all spec sheets, there is a claim that rear-curtain sync is supported.Perhaps they just copied the description from other variants of the same trigger. The Canon version, for instance, does indeed support rear-curtain sync.

I remember to read about the read-curtain sync on some Godox manual. But when I got the Xpro-P I was looking for this setting, but didn't found it. On the XProC there is the SYNC button, and you cycle OFF/NORMAL-REAR-HSS sync modes; but on the XproP, I see just NORMAL-HSS modes.

The RF60x is a single-pin flash anyhow, so any on-camera use would imply M mode anyhow (except when you use a V6II in between and isolate the hot-shoe contacts in order to avoid interference with the radio triggering).However, you are correct in pointing out that when mounting the V6II on the X2T, any off-camera RF60x would have to be run in "M" mode (with remote power control and probably the option to use manual HSS, though).

I mean exactly that, as you put the Cactus on a single pin shoe, it will not receive any TTL control from the camera, so just M option to trigger flashes. Thanks for the appointment .
About HSS, I noticed that the X2T shoe 'fires' when you use speeds above sync, so I think It will be possible to get HSS with the RF60x.

To combine Godox and Cactus lights, it might be more promising to put the X2T on top of the V6II. Selecting one of the available flash profiles on the V6II might do the trick of letting the X2T operate as if it were mounted on the camera (haven't tried this yet as I haven't had a need to mix lights).

It's good anyway that he'll have two options, he can try what works better.

---------- Post added 06-10-19 at 06:32 PM ----------

Yeah, but having to change this on an off-camera unit makes it way less practical than it should be.In particular, because the delay is of course depended on the shutter speed. Change the latter and its off to making a tour through all the off-camera lights you are using.

I'm afraid is the only way to get rear sync .

[Class A]

If one is using delay, why would there be need for TTL?

If you use a manual delay setting, you indeed don't need TTL/P-TTL.

P-TTL is just for making it more easy?

Yes, P-TTL provides automation, but nothing that you couldn't achieve manually (in principle).

Technically, it is not feasible to manually adjust the flash exposure along with a dynamically changing scene but that disadvantage of manual flash power level control is offset by more predictability and consistency. I only used P-TTL in test situations. Sometimes, the P-TTL exposures can be surprisingly useful. Much more often than acceptable, though, AFAIC, P-TTL exposures can be really off. If they are not spot -on and one has to start tweaking with flash exposure compensation then one is, in my view, better off tweaking manually.

Some radio triggers have a feature that allows you to take a shot using P-TTL (automatic flash exposure) and then convert the power level chosen by the camera into a manual level. That, in principle, could combine the best of both worlds but relies on P-TTL getting it pretty much right the first time, which is not always the case.

What I have noticed is that with HSS in little brighter daylight with 360 and you can’t see if something happened or not.

Yes, even an AF 540 FGZ runs out of steam in bright daylight very quickly.

The problem is twofold:

1. HSS bursts need to be lower in maximum power because they need to maintain a high output for longer than a normal flash pulse.
2. Increasing the shutter speed cuts down on HSS-flash exposure. With a shutter speed only four times as fast as the sync-speed, you are already losing two stops of flash power.

[Class A]

hanks for the appointment .

I didn't mean to lecture you, sorry if it came across like that.

I wrote the paragraph for the benefit of @repaap.
I was confident that you didn't need the information but didn't feel like making it very explicit in my phrasing.

About HSS, I noticed that the X2T shoe 'fires' when you use speeds above sync, so I think It will be possible to get HSS with the RF60x.

The X2T could then be the "long-awaited" abolisher of the no-fire-above-sync-speed limitation that all Pentax DSLRs impose.

Should be easy to use HyperSync with very old flashes, for instance, or use lights that support manual engagement of HSS.

[repaap]

If you use a manual delay setting, you indeed don't need TTL/P-TTL.


Yes, P-TTL provides automation, but nothing that you couldn't achieve manually (in principle).

Technically, it is not feasible to manually adjust the flash exposure along with a dynamically changing scene but that disadvantage of manual flash power level control is offset by more predictability and consistency. I only used P-TTL in test situations. Sometimes, the P-TTL exposures can be surprisingly useful. Much more often than acceptable, though, AFAIC, P-TTL exposures can be really off. If they are not spot -on and one has to start tweaking with flash exposure compensation then one is, in my view, better off tweaking manually.

Some radio triggers have a feature that allows you to take a shot using P-TTL (automatic flash exposure) and then convert the power level chosen by the camera into a manual level. That, in principle, could combine the best of both worlds but relies on P-TTL getting it pretty much right the first time, which is not always the case.



Yes, even an AF 540 FGZ runs out of steam in bright daylight very quickly.

The problem is twofold:

1. HSS bursts need to be lower in maximum power because they need to maintain a high output for longer than a normal flash pulse.
2. Increasing the shutter speed cuts down on HSS-flash exposure. With a shutter speed only four times as fast as the sync-speed, you are already losing two stops of flash power.

Thank you for clearing that up. Something that I suspected. And i can confirm that P-TTL is sometimes just spot on and sometimes not even close. One thing to find out of what does that pre flash meter. is it the focusing point or? and if so, what all you have to take in consider. I think that I have some sort of idea of what and how to. But there are also some odd things. Lot of that is also that I just bought my first P-TTL flash week a go and have been exploring since. I have my elichrome stuff which is manual all. No surprises. Still a lot of work Going to explore HSS with triggering with my AF369FGZ, since it should be possible. But then again, that could be going alover the place!

[morenjavi]

I didn't mean to lecture you, sorry if it came across like that.I wrote the paragraph for the benefit of @repaap.I was confident that you didn't need the information but didn't feel like making it very explicit in my phrasing.

Absolutely no problem with that. I found your clarification entirely adequate and useful. This is a friendly forum . My apologies if my comment has been annoying in any way.

The X2T could then be the "long-awaited" abolisher of the no-fire-above-sync-speed limitation that all Pentax DSLRs impose.Should be easy to use HyperSync with very old flashes, for instance, or use lights that support manual engagement of HSS.

I agree, I made a few tests with flashes with and without manual HSS, and it worked, looks promising. You only need a pair of cheap trigger/receiver, but you can sync a flash just putting directly on the top hot shoe. Now I just need Godox to fix the X2T firmware for legacy flashes, and it will be perfect . Ah, also a longer delay setting for rear curtain sync would be another good adition.

[Class A]

One thing to find out of what does that pre flash meter.

Do you mean you are wondering what the pre-flash is about when using P-TTL?

The earlier analogue TTL system measured the reflectance of the light from the film and cut-off the flash power in real time when the desired exposure level was achieved.

This approach doesn't work well with digital sensors so modern flash systems use a short and weak pre-flash to illuminate the scene to give the camera's light meter a way to measure the reflectance of objects in the scene. Based on that meter reading, the camera calculates the power for the main flash. This explains some of the error scenarios one can run into in which either the pre-flash power was way too weak or way too strong for a particular scene. A further error scenario is defined by highly reflective objects in the scene, such as mirrors, that will dominate the metering result and hence lead to an exposure that is too low overall.

The pre-flash is not used for AF. It is too short to help with AF.

N.B., the need for a pre-flash introduces a small but noticeable delay (caused by both firing the flash and then computing the appropriate output level). A manually controlled flash can engage a fraction of a second more quickly. For that to work, however, P-TTL must not be operational, i.e., whenever one wants to use a P-TTL-based feature such as HSS or rear-curtain sync, the delay will be there, whether one uses the automated metering function (i.e., a pre-flash) or not.

[repaap]

Do you mean you are wondering what the pre-flash is about when using P-TTL?

The earlier analogue TTL system measured the reflectance of the light from the film and cut-off the flash power in real time when the desired exposure level was achieved.

This approach doesn't work well with digital sensors so modern flash systems use a short and weak pre-flash to illuminate the scene to give the camera's light meter a way to measure the reflectance of objects in the scene. Based on that meter reading, the camera calculates the power for the main flash. This explains some of the error scenarios one can run into in which either the pre-flash power was way too weak or way too strong for a particular scene. A further error scenario is defined by highly reflective objects in the scene, such as mirrors, that will dominate the metering result and hence lead to an exposure that is too low overall.

The pre-flash is not used for AF. It is too short to help with AF.

N.B., the need for a pre-flash introduces a small but noticeable delay (caused by both firing the flash and then computing the appropriate output level). A manually controlled flash can engage a fraction of a second more quickly. For that to work, however, P-TTL must not be operational, i.e., whenever one wants to use a P-TTL-based feature such as HSS or rear-curtain sync, the delay will be there, whether one uses the automated metering function (i.e., a pre-flash) or not.

Gotcha! Sorry about highjacking this thread, but this is atleast connected to main questions. This kind a is also making my observations so far to be almost there. Manual all is safest way to go. If one want to have the best result. With p-ttl it is just handy but light or reflective surfaces can throw it to the wall..

These new powerful Godox flashes with possibility to p-ttl is in that way gamechanges that these tools were not so easily available. But all in all if someone fancy HSS outside. They better be ready to get ’thatmuch’ more powerful flash.

[BruceBanner]

Yes, but just to be clear, that's the nature of HyperSync/PowerSnc/...Sync in general.

If one has the funds, it's way easier to add flashes and use HSS, instead of messing about with HyperSync.



This has always been a flash-feature in the Pentax system. In other words, the K-1 "operates as designed'.

EDIT: However, if the Godox triggers actually support rear-curtain sync on Pentax cameras that support the respective configuration (see below), it could be that the K-1 is unnecessarily handicapped indeed...

What makes you think the KP is different? Perhaps you are right, I just never heard of the KP doing anything differently in that regard.
Note that just because the KP -- as other cameras -- offer a rear-curtain sync option, doesn't mean that an attached flash will operate in rear-curtain sync mode. The flash has to support the feature natively, unfortunately.


I don't think so, but I could be wrong.

At least, there is no configuration option for rear-curtain sync on the triggers. Both are advertised as being able to support rear-curtain sync, but no option becomes available on the K-1, when the trigger is mounted, so I wouldn't know how to activate rear-curtain sync. Maybe it would work on a camera that always gives one the rear-curtain sync option, no matter whether the flash offers to support it? Let me know if you want me to try it.



On the Godox triggers, the delay range is not big enough to implement a poor man's rear-curtain sync.
The Godox delay is just meant for adjusting the HyperSync sychnronisation.



Which hurdles are you referring to?

Note that the X2T-P only has a single pin hot-shoe. A mounted Cactus V6II would not be able to operate in HSS mode.
I haven't done any tests yet regarding the timing of the X2T-P hot-shoe triggering. It could support work around techniques, if you want to use your RF60x's in manual HSS mode.

In contrast to the Godox XPro manual, the Flashpoint R2 Pro MarkII manual, explicitly mentions "second-curtain sync" (on page 19).

Mine is still on backorder so I cannot experiment yet.

Regarding Hypersync, yep I knew that, hence testing on a large wall to see how and where the banding was exactly and which delay figure worked best. I found it very bizarre that it's default 0 (out of 20 I think IIRC?) actually was such a delay that it appears no flash fired at all, there was no difference to the shots if I had flash on or off. This stumped me for a bit. I think around 7/20 was where I got most of the banding to be shared equally between top of the frame and bottom.

This was one such shot where I used Powersync/Hypersync, I fired it through some modifiers to still try and have some gentle shadow to light transitions than what bare would have given, but the top of his hat really stuffed up my plans and it was very dark compared to the rest of him, I had a lot more dodging work to do to make it a better shot;



(shadow on his eyes/under hat was a deliberate artistic intent, going for mysterious etc).

Another instance where Powersync came in handy was for this shot for a client;



It's the underside of the Lennox Bridge, the oldest bridge in NSW (Australia) I believe. Regular HSS was not reaching the arch well enough, and after enough test shots with Powersync I realised that's the level of power I needed. The shot in the end however was taken at 1/60 and an aperture chosen to help keep it under HSS speeds. Still, it was interesting to find a target that HSS failed to reach vs either Powersync or 1/1 under sync speed.

I am likely to buy some Xume filter holders, it may be that I will use ND Filters a lot more in future just to avoid HSS when using speedlites. AD200's might solve that issue entirely of course (kick ass power), however there may still be those occasions where I feel I just want to take something smaller and lighter.


So within the KP Flash system menu, rear curtain is there to select. I believe this is because the KP has a built in flash so Pentax felt the need to include it in the menu of the camera body. K1 has no pop up flash, so it's been left out of the menu, and instead the official Pentax flashes have that option on the flash to select. It's just one of those Pentax things, it's like Pentax believes its customers are likely to go no further with flash than on body, after all they never bothered with even making a wireless trigger (even something like developing a Tx and Rx system for their own flashes... <sigh>).

I didn't know Godox's delay was for Hyper only, good to know. Seems Cactus wins again on this front by allowing for a significant delay.

My main hurdle is still slightly unknown to me. The direction I wish to take is school photography, but done quite differently to what the majority of providers are currently doing, so it's not something that is going to be easily comparable. Limited funds also mean my migration to fully pop over to Godox will mean a mish-mash of cactus + godox systems working together in a studio condition. This would mean working under 1/200 and in manual mode, so I doubt HSS or P-TTL is anything I am going to care about. I am yet to decide on my lighting style, placement and what not, it could be I will have 2xAD200 in a ADB2 bracket for keylight (rotating/sharing turns to keep temps down) and a similar setup with 2xRf60x units for rim lighting doing a similar thing. I might need more power though. I could optically trigger but I think I'd rather stack triggers to get some more solid firing going.

Initially I wasn't sure with the Xpro-P how that was going to work, and that the V6ii might be first and Xpro-P second (in the stack). It seems the X2T might allow for the other way around...

One small thing that concerns me about the X2T is that (apparently) it doesn't support TCM. I only found out what that was recently, it's when you're in P-TTL mode and then take a shot in that mode, you can then use TCM for it to toggle you over to the Manual power equivalent of what that P-TTL shot was taken at. With the event photography I do (running & gunning) I can see this as actually being really useful, fire one P-TTL shot off, chimp, use TCM and then dial it in better and more accurately for the successive shots (I have had too many whacky bizarre exposures with P-TTL where perhaps 2/10 shots are really way off, actually blinding people etc lol, I really avoid it where possible, but I always thought it was a nice 'starting point' and so must have others for the TCM feature to be implemented).

The X2T doesn't suppor rear curtain, just front. The same is for the Xpro-P. The delay I'm taliking about have a range from 0 to 9.9ms, it's just too short to implement a second curtain, this setting is just to play with high speed sync.
But, you have a setting on the AD200, that is more adequate for this task, you can configure the F4 setting, this is a delay setting in the range 0,01-30 sec. Not too comfortable (you have to set in on the flash), but yo can get a second curtain sync with it.
I have tested this setting with the XPro-P and X2T and it works (I tried 1,5s of delay), but only in M mode (so no TTL + second curtain sync).


I have made a quick test putting a Cactus V6II on top of the X2T and it seems to fire (Cactus green led blinks), just remember the X2T's shoe is single pin, so you could use your RF60x's, but only in M mode. It's just a gessing, I don't have any RF60 to test, but it makes sense to me.

I thought the same but you'll note that in all spec sheets, there is a claim that rear-curtain sync is supported.

Perhaps they just copied the description from other variants of the same trigger. The Canon version, for instance, does indeed support rear-curtain sync.


Yeah, but having to change this on an off-camera unit makes it way less practical than it should be.

In particular, because the delay is of course depended on the shutter speed. Change the latter and its off to making a tour through all the off-camera lights you are using.


The RF60x is a single-pin flash anyhow, so any on-camera use would imply M mode anyhow (except when you use a V6II in between and isolate the hot-shoe contacts in order to avoid interference with the radio triggering).

However, you are correct in pointing out that when mounting the V6II on the X2T, any off-camera RF60x would have to be run in "M" mode (with remote power control and probably the option to use manual HSS, though).

To combine Godox and Cactus lights, it might be more promising to put the X2T on top of the V6II. Selecting one of the available flash profiles on the V6II might do the trick of letting the X2T operate as if it were mounted on the camera (haven't tried this yet as I haven't had a need to mix lights).

Well that's good to know an AD200 can to rear curtain sync. Really there has been few occasions I've had to use it, one was a long exposure of the stars with a final pop of flash at the end for the portrait of the person gazing at the stars etc. In this regard the fact its done on the flashes is not such a deal breaker for me, its not the kinda fast pace shooting scenario.

If you like to try the other way around and have v6ii leading with the X2T on top, that would be good, I think you have done this already for me with the X-Pro and it worked fine?

I remember to read about the read-curtain sync on some Godox manual. But when I got the Xpro-P I was looking for this setting, but didn't found it. On the XProC there is the SYNC button, and you cycle OFF/NORMAL-REAR-HSS sync modes; but on the XproP, I see just NORMAL-HSS modes.


I mean exactly that, as you put the Cactus on a single pin shoe, it will not receive any TTL control from the camera, so just M option to trigger flashes. Thanks for the appointment .
About HSS, I noticed that the X2T shoe 'fires' when you use speeds above sync, so I think It will be possible to get HSS with the RF60x.



It's good anyway that he'll have two options, he can try what works better.

---------- Post added 06-10-19 at 06:32 PM ----------


I'm afraid is the only way to get rear sync .

Are you meaning to say that with the X2T, outside, f1.8 1/5000 ISO 100 etc, if that is what the camera is seeing you don't need to press a dumb 'sync' button to get into HSS? It will (like Cactus) just fire in HSS because it can see that it has high shutter speeds anyway? Does the Xpro-P differ in this regard?

I didn't mean to lecture you, sorry if it came across like that.

I wrote the paragraph for the benefit of @repaap.
I was confident that you didn't need the information but didn't feel like making it very explicit in my phrasing.


The X2T could then be the "long-awaited" abolisher of the no-fire-above-sync-speed limitation that all Pentax DSLRs impose.

Should be easy to use HyperSync with very old flashes, for instance, or use lights that support manual engagement of HSS.

I like lectures, keep them coming

Gotcha! Sorry about highjacking this thread, but this is atleast connected to main questions. This kind a is also making my observations so far to be almost there. Manual all is safest way to go. If one want to have the best result. With p-ttl it is just handy but light or reflective surfaces can throw it to the wall..

These new powerful Godox flashes with possibility to p-ttl is in that way gamechanges that these tools were not so easily available. But all in all if someone fancy HSS outside. They better be ready to get ’thatmuch’ more powerful flash.

[morenjavi]

If you like to try the other way around and have v6ii leading with the X2T on top, that would be good, I think you have done this already for me with the X-Pro and it worked fine?

I tested this combination with the Xpro and worked. Remember, months ago, all the posts related to stack the Xpro trigger on top of the Cactus trigger, playing with the settins and firmware options, to get HSS for our Pentax cameras.

But It's ok. I have made a test, just for you :

Cactus V6II with firmware 1.1.013, PENTAX camera, MANUAL FLASH, POWER SYNC.
X2T with HSS sync off (not needed for this test)

As a remote flash, I have my AD360.
Camera in M mode, as usual for me .

Firing at 1/160 speed: AD360 is fired and synched perfectly.
Firing at 1/400: AD360 is fired but you get a black pic. The AD360 is obviously out of sync now.

On this point, you can:
1. Adjust DELAY setting on X2T -> it has no effect at all. I think this setting works only when the X2T has detected a Pentax camera.
2. Adjust the POWER SYNC ADJ on the Cactus to 24 -> you get a near complete frame (exceeding the SYNC)
3. Enable HSS manually on the AD360 -> you get a frame fully illuminated (HSS SYNC)
3. Set the AD360 to full power -> you get a frame fully illuminated (Power SYNC)

I'm not sure how useful is this test, because I can get all of the above without the Cactus and the X2T stacked on top.

I made the same experiments with the AD200. Point 3 does not work with the AD200, because you can't force HSS on the AD200 if you have the wireless mode enabled.

Are you meaning to say that with the X2T, outside, f1.8 1/5000 ISO 100 etc, if that is what the camera is seeing you don't need to press a dumb 'sync' button to get into HSS? It will (like Cactus) just fire in HSS because it can see that it has high shutter speeds anyway? Does the Xpro-P differ in this regard?

I'm not sure If I understand your question. The X2T & XproP have a SYNC mode that can be enabled or disabled. This mode allows the camera to go beyond the maximum sync speed, if this mode is disabled, you can go only to 1/180 (APS-C) max. But this mode does not set anything related to HSS on the remote flash (in this case the AD200). When you go beyond the sync speed and fire, the X2T/XPro sets the remote flash in HSS mode and sync with it automatically. If you return to under-sync speeds, it sets the flash in normal mode. I 'know' it because you can see the AD200 rear display and it changes the HSS icon depending on your camera speed. This is how I understand this trigger works, in my experience.
Remember that you'll have a signal on the X2T's show, regardless the camera speed. It's up to you to take advantage of it to sync any other device.

[EDIT] The HSS icon is changed when you fire, not when you change speed on your camera or enable/disable the HSS SYNC mode on the trigger.

Regards.

[Class A]

One small thing that concerns me about the X2T is that (apparently) it doesn't support TCM.

Yeah, it doesn't.

God(ox) knows why not.

If Flashpoint ever make a "MarkII" version of the X2T then chances are that TCM could become available.

Well that's good to know an AD200 can to rear curtain sync.

Not sure where you've got this from.

I'm pretty sure with some arrangements it could be made to, but I'm not aware of any convenient out-of-the-box approach that would accomplish it with Pentax (with Canon, it would work).

If you like to try the other way around and have v6ii leading with the X2T on top, that would be good,...

What would you like me to test specifically?
EDIT: it seems morenjavi has done the work already. Thanks!

Are you meaning to say that with the X2T, outside, f1.8 1/5000 ISO 100 etc, if that is what the camera is seeing you don't need to press a dumb 'sync' button to get into HSS?

You never have to (always) press a dumb sync button on the Godox triggers. Both Xpro and X2T triggers require a one time activation of HSS and from then on it works pretty much like the Cactus system. I'm not sure whether the flashes revert to normal flash pulses for shutter speeds that do not exceed the sync-speed (like they do with the Cactus systems).

I've used the Xpro-P for a number of real shoots but I haven't done any extensive testing with the equipment yet. Not enough time in the day.

[morenjavi]

What would you like me to test specifically?
EDIT: it seems morenjavi has done the work already. Thanks!

I understood he was asking me about this, The same about the question related to the 'dumb sync button'. My apologies!

[Class A]

Cactus V6II with firmware 1.1.013

That's the one I'm using as well. Seems we both prefer the multi-brand over the X-TTL variant.

Adjust the POWER SYNC ADJ on the Cactus to 24 -> you get a near complete frame (exceeding the SYNC)

It seems you are indicating that the adjustment range isn't enough.
Try setting the (unhelpfully named) "CUSTOM FUNCTION" to a different type. The latter influences the timing to allow for differences in various Pentax cameras. This may shift the adjustable range into a more useful territory.

I'm not sure how useful is this test, because I can get all of the above without the Cactus and the X2T stacked on top.

But the point of stacking was to operate both Cactus and Godox equipment at the same time, right?
There are other ways, but stacking is the most straight-forward and convenient.

Point 3 does not work with the AD200, because you can't force HSS on the AD200 if you have the wireless mode enabled.

Really? Even in "wireless mode", the AD200 responds to a long press on the bottom right button with activating HSS. Does this not do the trick?

But this mode does not set anything related to HSS on the remote flash (in this case the AD200).

It has to. Otherwise, you wouldn't get full frame exposures.

EDIT: I noticed that you wrote that there is indeed an HSS-activation effect when the shutter speed exceeds the sync-speed. Not sure then why you'd first say "does not set anything related to HSS on the remote flash" (because it does, when necessary). But the main thing is it works and very nice of you to confirm that HSS is disabled again when using shutter speeds that don't require it.

[Class A]

I understood he was asking me about this, The same about the question related to the 'dumb sync button'. My apologies!

Not at all! All good.

[morenjavi]

It seems you are indicating that the adjustment range isn't enough

This setting works for me on most cases, but depending on the trigger or flash you stack on the Cactus, you need to change it a bit, sometimes you need 22, sometimes 26, but 24 is more or less fine. In this test you can't get the full frame illuminated because the speed, at 1/400 curtains start to block the frame, so you get a dark band above or below the frame.

Really? Even in "wireless mode", the AD200 responds to a long press on the bottom right button with activating HSS. Does this not do the trick?

Yes, in my experience, you can press the HSS setting, and you can see that the icon appears on the display, but nothing changes when you fire (or maybe the problem is another one). I noticed this behaviour time ago, when I was doing experiments stacking the XPro for Canon on top of the Cactus V6 II. If you disable the wireless mode, and put a XTR16 receiver on the USB port, then yes, you can really enable/disable HSS manually on the AD200. By doing this, you have 'downgraded' your AD200 to a legacy Godox flash.

It has to. Otherwise, you wouldn't get full frame exposures.

The remote flash may not indicate via the display that it is operating in HSS mode, but it will. Activating HSS mode is the entire point of using the (HSS-)sync button on the triggers.

Let me explain. Of course I can't see if the X2T is talking with the remote flash when you enable or disable the SYNC mode on the trigger, but nothing is changed on the remote display. The only 'effect' I can notice is that the camera speed is allowed to go beyond the sync speed or not. When I fire, then I see that the HSS mode is enabled/disabled on the AD200, so my understanding is that the HSS mode (power setting, etc) is set at the moment of firing.

---------- Post added 07-10-19 at 01:57 PM ----------

@Class A, please have patience with me , in my mother language (Spanish) my sentences are most of the time confusing and hard to understand; when I translate my confusing ideas to English, the problem only get worse . Sometimes I just can't express well enough what I mean, and can lead to misunderstandings.

---------- Post added 07-10-19 at 02:09 PM ----------

But the point of stacking was to operate both Cactus and Godox equipment at the same time, right?
There are other ways, but stacking is the most straight-forward and convenient.

Right, I was so focused doing the tests that I forgot about the main point.

[Class A]

In this test you can't get the full frame illuminated because the speed, at 1/400 curtains start to block the frame, so you get a dark band above or below the frame.

Yes, too short a flash cannot be fixed with the sync adjustment.

Yes, in my experience, you can press the HSS setting, and you can see that the icon appears on the display, but nothing changes when you fire (or maybe the problem is another one).

Ah, so the wireless mode overrides the manual setting. Seems unlikely there is a way then, while still using the built-in receiver.

The only 'effect' I can notice is that the camera speed is allowed to go beyond the sync speed or not.

Sure, but there is the implied effect that remote flashes will operate in HSS mode for higher shutter speeds.
Just a question of how to interpret a sentence.

Sometimes I just can't express well enough what I mean, and can lead to misunderstandings.

No problem at all!

I'm glad that you are making great contributions to this forum!