[kaseki]

"Cactus 6VII confusion" may may be a mundane topic in this flash section, but here are my questions that I either haven't seen answered in other threads or which there seem to be conflicting answers.

(a) In Class A's review of the V6 on page 5 of Cactus V6 Review - Introduction | PentaxForums.com Reviews, the V6 is described as capable of taking an analog TTL capable flash and making it useful as a variable power RF controlled remote slave flash by using a calibration technique to generate a custom flash profile.

Is this capability still available in the V6II? If so, is there any known impediment to doing so with the Pentax AF-500FTZ flashes? (I have several.)

(b) The Cactus flash uses firmware upgrade tools that are officially supported only via Windows and Mac operating systems. As I have only Linux on my various PCs, the OS requirement may be an impediment, depending on how the firmware is stored in the V6II. For example, it was trivial under Linux to load updated 645Z firmware onto one of the camera's memory cards. I believe, but haven't tested, that the USB interface with the 645Z makes the camera appear as a memory card, so I suspect I could have upgraded directly (but was too chicken to try with a new camera).

So, does the V6II appear to a USB port as a memory card or other storage device so that it can be written to using normal copy/paste file operations? Does the installation software perform some functions on the supplied firmware file that cannot otherwise be easily performed by other means, e.g., hidden parameter encryption/decryption? If direct Linux upgrading is not possible due to such operations, is anyone aware of successful use of Wine or Crossover Linux to act as a Windows substitute for the purpose of running the Windows firmware upgrade software?

Thanks

[MatKus]

Can't help you with first question. I don't have such lamp.

And about updates - on windows you must download and install their program. Then, when you connect V6ii or rf60x it is detected by this program, it downloads and installs update. Hard to say if it will run on wine or in some other way on Linux.

[mcgregni]

As I understand it, (and this has mainly come from ClassA as our resident Cactus expert), the V6II needs the newer digital (P/E/i-TTL) protocol for communication and power control . It cannot control older analogue TTL flash types.

The V6 uses the older analogue tech that is latent in most modern TTL models, to gain control over power remotely. So that is a brief summary of the situation as I understand it ....

I have seen it written here that the 500FTZ is not compatible.

[kaseki]

As I understand it, (and this has mainly come from ClassA as our resident Cactus expert), the V6II needs the newer digital (P/E/i-TTL) protocol for communication and power control . It cannot control older analogue TTL flash types.

The V6 uses the older analogue tech that is latent in most modern TTL models, to gain control over power remotely. So that is a brief summary of the situation as I understand it ....

I have seen it written here that the 500FTZ is not compatible.

So, might not a V6 (which Cactus claims is compatible with the V6II) be able to do the profiling (if compatible with the 500) and the V6II be able to talk to it and command power levels and maybe even zoom beamwidth, as well as operate in quasi manual mode (no analog TTL; no HSS)?

Sometimes standardization, de jure or de facto, causes lost technological capability (e.g., VHS vs. Beta until both became moot), but other times lack of it impedes wide adoption of a technology. I think it desirable that there be less agony trying to mix and match cameras, flashes, and communication modules.

[kaseki]

Unfortunately, I've discovered that the answer to subject (a) related questions is NO. The 500FTZ has some "feature" that blocks the V6 from learning. See Pentax: Cactus 6 VII support for p-TTL and TTL ? Cactus Community

[UncleVanya]

From past experience (I owned that flash) the V6 will not work with it. The reasons are convoluted but allow me to explain what I think I understand:

There are multiple TTL modes for Pentax flashes - the version supported in the V6 is an analog version used in digital bodies. The version in the 500FTZ is a digital version that is not supported and was used by some later film bodies. (See this thread for more info: Af500ftz and cactus v6? - PentaxForums.com) No one ever seemed to find a way to work it out with v6ii either but that's not surprising as the digital TTL it supported was the Off the Film Plane variant not the Preflash variant.

[kaseki]

From past experience (I owned that flash) the V6 will not work with it. The reasons are convoluted but allow me to explain what I think I understand:

There are multiple TTL modes for Pentax flashes - the version supported in the V6 is an analog version used in digital bodies. The version in the 500FTZ is a digital version that is not supported and was used by some later film bodies. (See this thread for more info: Af500ftz and cactus v6? - PentaxForums.com) No one ever seemed to find a way to work it out with v6ii either but that's not surprising as the digital TTL it supported was the Off the Film Plane variant not the Preflash variant.

I just wanted to make the AF-500FTZs re-purposed remote-controlled mini studio flashes. They can do what I want in slave mode but I have to set the power in each slave and adjust range to get the desired irradiance (illuminance) on the subject.

In any case, thanks. If the control of the analog TTL is digital, then the V6 would have to have a specifically tailored (bespoke) communication link relative to other analog-controlled analog TTL flashes.


---------- Post added 6th Aug 2018 at 17:18 ----------

W.r..t. subject (b), attempts to install the Cactus firmware tool into a Crossover Linux Win 7 bottle have not been successful. .NET 4 is needed, and the installer hangs trying to download it.

Later....
.NET 4 requires a Linux package that the Cactus installer wouldn't know about. So it was necessary to install .NET 4 individually. I can get the Cactus installer to start, but it doesn't see a device to load the firmware to (because I don't have one, at a minimum) so it is waiting for the next step.

In other words, it is possible that the V6/V6II/RF60/etc. can be supported by at least one Linux flavor, in my case Mint 64-bit MATE (and probably any Linux that Crossover supports).

---

Last edited by kaseki; 08-06-2018 at 02:33 PM.

[pid]

the AF 500-FTZ only works in manual mode with both cactus versions, but there is no way to control the flash power with the cactus. You have to set the power of the flash directly at the flash in his own maual mode. I talked to cactus a while ago and they couldnt help, because they dont have a copy of the pentax flash to find a way to get it controlled by the cactus. write to them at facebook or the community blog of cactus. The more people asking, te bigger the chance they look for a solution.

[Class A]

Is this capability still available in the V6II?

As already stated before, the V6II did not retain the ability to talk to analogue TTL flashes.

If so, is there any known impediment to doing so with the Pentax AF-500FTZ flashes?

The AF-500FTZ is a strange animal that has a leg in both analogue and digital worlds and hence unfortunately neither works with the V6 nor the V6II.

So, does the V6II appear to a USB port as a memory card or other storage device so that it can be written to using normal copy/paste file operations?

To the best of my knowledge the V6II does not emulate a mass storage device.

I hope you can get your Linux solution to work.

[kaseki]

... I talked to cactus a while ago and they couldnt help, because they dont have a copy of the pentax flash to find a way to get it controlled by the cactus. ...

The AF-500FTZ flash only costs about $40 - $60 on eBay. However, I think that they would need a 645N body and a lens to generate correct messages, and a Pentax 5P cable and an F connector to easily tap into the communications. That would add a bit of initial expense, most of which could be recovered afterwards by selling everything but the cut up cable on eBay. However, the labor cost of doing the signals exploitation would certainly be much greater than the parts cost, and I would surely expect Cactus to question how many more units they could sell with the added capability in order to pay for the exploitation, coding, and testing expenses.

---------- Post added 6th Aug 2018 at 21:58 ----------

As already stated before, the V6II did not retain the ability to talk to analogue TTL flashes.

The AF-500FTZ is a strange animal that has a leg in both analogue and digital worlds and hence unfortunately neither works with the V6 nor the V6II.

To the best of my knowledge the V6II does not emulate a mass storage device.

I hope you can get your Linux solution to work.

Thanks. I might be able to test it once I decide what I really need and whether one or more of the Cactus V6 products fits into that need.

For my 645N, the 500FTZ flashes all operate in analog TTL mode when cabled together. They can operate as selected power level manual slaves using direct and reflected flash triggering over "residential studio" distances, and my Minolta Flashmeter IV from my distant past can be used to establish just what power setting each flash needs to be set to for a given lighting configuration.

So I think it is clear now from the limitations of what can be done with the 500FTZ that it is only the 645Z compatible P-TTL and HSS modes that I now have to find a solution for, once I establish how complex or simple my "needs" really are.

[kaseki]

In a BruceBanner initiated thread centered around brackets, mcgregni wrote: "Just to clarify, the TTL passthrough applies to a P-TTL dedicated system flash, not the RF60x. The RF60x can only provide TTL when operating as a radio slave, controlled from the V6II, both with X-TTL firmware."

Read more at: Do you even need a Flash Bracket if using a flash modifier such as Mogmod sphere? - Page 2 - PentaxForums.com

This statement really cuts to the core of the thousands of seemingly conflicting words I have recently read trying to make sense of what does and doesn't work, so please let me drop the original AF-500FTZ aspect of this thread and try to ensure I understand Nigel's message.

Using a 645Z, K3, or similar operating Pentax digital P-TTL camera, which of the following statements are true?

1. An AF-540FGZII mounted on a Cactus V6II set into pass-through mode will operate as a P-TTL flash as if the V6II is not there (from the camera's point of view)
2. In this mode, the V6II can "tap" the camera's flash control signals and thereby also control remote R60X flashes as additional P-TTL flashes
3. In P-TTL mode, the additional R60X flashes operate such that each flash generates a pre-pulse and each flash's pre-pulse in some way adds to the camera's detected pre-pulse light level, just as if additional optically-communicating AF-540FGZII were present (assuming that is how they work)
4. With the V6II mounted on the camera, but no flash mounted on the V6II and one or more R60X flashes used remotely (even if remotely means within inches) the R60X flashes can all operate in P-TTL mode as defined above, thereby eliminating any need for the AF-540FGZII's presence

Thanks!

[mcgregni]

Hi,

No 1 is correct if using the Multi-brand firmware .... If using XTTL firmware the P-TTL Passthrough flash must be controlled with the V6IIs interface.

No 2 is not quite correct ..... The V6 II uses the camera metering system to determine power output levels for the RF60x slaves in TTL mode.... No PTTL flash is required.(Perhaps that's what you meant anyway?)

3 is right. .... The pre-flashes are used by the camera metering system to determine the flash output , in the same way as multiple P-TTL flashes. The only difference is the Radio communications instead of optical.

4 is correct .

I'm glad my post stimulated the questions! ....

Edit .... Just thinking more about it, I suppose really it is the camera metering system that calculates the required flash EV, and the V6II that translates that into power output instructions for the slave flashes. It's worth noting that (just like for the Pentax optical wireless system), it is a global (combined total of all slaves) flash EV that is determined .... This is then split equally between the flashes (so a flash further away would output more light to balance the output from a closer flash). The compensation settings are an offset to this applied locally at each flash

Again, it's all the same as for the optical wireless system, just that the Radio remote control gives easier direct control over things.

One final thought about your point 3 ... There are two district types of optical "signals" emitted during pre-flashes ....metering illuminations and communication signals. The metering illuminations are read through the lens as brightness by the metering sensors. The communication signals are coded messages sent to the slave flashes to control them. In the case of RF60x flashes, only the first metering type of pre-flash applies .... There are no optical communication signals as this functioning is performed via radio waves instead.

[kaseki]

Hi,

No 1 is correct if using the Multi-brand firmware .... If using XTTL firmware the P-TTL Passthrough flash must be controlled with the V6IIs interface.

No 2 is not quite correct ..... The V6 II uses the camera metering system to determine power output levels for the RF60x slaves in TTL mode.... No PTTL flash is required.(Perhaps that's what you meant anyway?)

3 is right. .... The pre-flashes are used by the camera metering system to determine the flash output , in the same way as multiple P-TTL flashes. The only difference is the Radio communications instead of optical.

4 is correct .

I'm glad my post stimulated the questions! ....

Edit .... Just thinking more about it, I suppose really it is the camera metering system that calculates the required flash EV, and the V6II that translates that into power output instructions for the slave flashes. It's worth noting that (just like for the Pentax optical wireless system), it is a global (combined total of all slaves) flash EV that is determined .... This is then split equally between the flashes (so a flash further away would output more light to balance the output from a closer flash). The compensation settings are an offset to this applied locally at each flash

Again, it's all the same as for the optical wireless system, just that the Radio remote control gives easier direct control over things.

One final thought about your point 3 ... There are two district types of optical "signals" emitted during pre-flashes ....metering illuminations and communication signals. The metering illuminations are read through the lens as brightness by the metering sensors. The communication signals are coded messages sent to the slave flashes to control them. In the case of RF60x flashes, only the first metering type of pre-flash applies .... There are no optical communication signals as this functioning is performed via radio waves instead.

Thanks. My extended response was just eaten by the site somehow, so it will take a while to reconstruct.

---------- Post added 13th Aug 2018 at 20:39 ----------

Hi, ... I'm glad my post stimulated the questions! ....

Thank you. I think it will be helpful if I excavate the rabbit hole a smidgen further, if you are game. I have taken the liberty of rearranging your text.

No 1 is correct if using the Multi-brand firmware .... If using XTTL firmware the P-TTL Passthrough flash must be controlled with the V6IIs interface.

I would expect to be using A06 and PEN.A.001 firmwares. These are the XTTL relevant ones?

By "controlled" do you mean merely that the V6II must be directed via its user interface to allow the pass-through, or that the V6II meddles with the data being passed through?

No 2 is not quite correct ..... The V6 II uses the camera metering system to determine power output levels for the RF60x slaves in TTL mode.... No PTTL flash is required.(Perhaps that's what you meant anyway?)

I fear that I meant something entirely different expecting multiple P-TTL pre-flashes, but which upon reflection could imply a control process too Byzentine in operation to possibly work. So let me ask a simplified question: With one Pentax P-TTL flash mounted on the V6II operating in passthrough mode, and one or more R60X under RF control of the V6II, how many flash heads generate a pre-flash when the camera thinks it is in P-TTL mode and all the flashes think that they are in P-TTL mode?

3 is right. .... The pre-flashes are used by the camera metering system to determine the flash output, in the same way as multiple P-TTL flashes. The only difference is the Radio communications instead of optical.

One final thought about your point 3 ... There are two district types of optical "signals" emitted during pre-flashes ....metering illuminations and communication signals. The metering illuminations are read through the lens as brightness by the metering sensors. The communication signals are coded messages sent to the slave flashes to control them. In the case of RF60x flashes, only the first metering type of pre-flash applies .... There are no optical communication signals as this functioning is performed via radio waves instead.

I think the answer to the additional No. 2 question applies here also.

4 is correct.

But let me ask another simplified question: With no Pentax P-TTL flash mounted on the V6II, but with one or more R60X being under control of the V6II, how many flash heads generate a pre-flash when the camera thinks it is in P-TTL mode and the R60X flashes think that they are in P-TTL mode?

Edit .... Just thinking more about it, I suppose really it is the camera metering system that calculates the required flash EV, and the V6II that translates that into power output instructions for the slave flashes. It's worth noting that (just like for the Pentax optical wireless system), it is a global (combined total of all slaves) flash EV that is determined .... This is then split equally between the flashes (so a flash further away would output more light to balance the output from a closer flash). The compensation settings are an offset to this applied locally at each flash

Again, it's all the same as for the optical wireless system, just that the Radio remote control gives easier direct control over things.

Depending on the new answers, it would seem that one can operate with one V6II and one or more off camera (and connected by RF only) R60X flashes, avoiding the need for an AF-540FGZ, even when only a single P-TTL flash is needed.

[mcgregni]

Hi, yes, those firmwares you mentioned are the XTTL versions.

Every flash in a multi-flash P-TTL setup emits a pre-flash for metering. The camera reads a combination of all the light outputs. As far as I can surmise, this is a single global flash exposure measurement, with the pre-flashes occurring simultaneously. I don't think we are aware here that there is any way for the camera to assess individual flashes..... However in practice I have seen generally even lighting from two P-TTL flashes on initial metering, even when one is just a rim light. It seems likely that the same power level signal is sent to all flashes.
.I don't think we are aware here of any way that could be different

However the balance (ratio) of lighting is then controlled with individual flash compensation settings for each flash, which simply places that particular offset away from the metered output level.

A P-TTL flash in passthrough on the V6II, plus all RR60x slaves will all emit simultaneous pre-flashes.

The RF60x model functions as a P-TTL slave, but only when controlled by a V6II with the XTTL firmware versions. There is no need for any Pentax system flash when operating the Cactus system this way

[kaseki]

Hi, yes, those firmwares you mentioned are the XTTL versions.

Every flash in a multi-flash P-TTL setup emits a pre-flash for metering. The camera reads a combination of all the light outputs. As far as I can surmise, this is a single global flash exposure measurement, with the pre-flashes occurring simultaneously. I don't think we are aware here that there is any way for the camera to assess individual flashes..... However in practice I have seen generally even lighting from two P-TTL flashes on initial metering, even when one is just a rim light. It seems likely that the same power level signal is sent to all flashes.
.I don't think we are aware here of any way that could be different

However the balance (ratio) of lighting is then controlled with individual flash compensation settings for each flash, which simply places that particular offset away from the metered output level.

A P-TTL flash in passthrough on the V6II, plus all RR60x slaves will all emit simultaneous pre-flashes.

The RF60x model functions as a P-TTL slave, but only when controlled by a V6II with the XTTL firmware versions. There is no need for any Pentax system flash when operating the Cactus system this way

Thank you, thank you, thank you. The rabbit hole excavation was sufficient to not only see the light, but also the Cheshire cat's smile.

kas