[Class A]

I was thinking the same thing, but then I thought that during the learning mode, the sensor on the V6 was monitoring flash duration time, rather than intensity.

To the best of my knowledge, it is only looking for intensity.

Look forward to hearing your results.

I personally don't have ND filters.

I'm not sure I'll find the time to try your other idea in the next couple of weeks.

I guess if that does work you could get similar results using black gaffer tape over 50% of the flash head. Kinda kludgy and maybe that would get too hot.

Cool idea!

In order to avoid heat issues, I wouldn't attach anything to the head itself. Just blocking half the light with a "gobo" should do. Without some dedication, this will only give very approximate results, but that could be all one needs.

I'm still a bit sceptical about the required recycling speed. A quick flash may be able to do it for the 1/2 and 1/4 levels (and more are not needed), but then such quick flashes tend to have full manual control anyhow, don't they?

I hope I'll be able to find the time to at least test the recycling challenge.

[awaldram]

Class A

Great review , Just a quick question

Does the V6 alllow full P-ttl pass thru.?

i.e can I put a 540 ontop of it and shoot p-ttl as if its not there ?
Your review implies it will not work due to non center pin triggering but neither the Nikon or Canon use center pin triggering for their solutions and it seems they pass through.

My reasoning is at present I shoot a mix of Metz 45's on Auto (rf center pin triggers pc sync) and a number of p-ttl flashes fired via optical or aokatecs depending on environment

It works but I'm often left wanting to alter the flash ratio during a shoot but can't change the 45's without visiting each of them

There all capable of TTL so should be controllable from the V6 trigger.on the camera, providing full pass thru is implemented my P-ttl flashes will be unaffected

You advice not to cover a flash head with anything but flash gells is very sound I have a Metz 53 with burn marks where a set a tissue paper diffuser alight being cheap

---------- Post added 12-05-14 at 12:11 PM ----------

Meanwhile, I've come across a solution which involves ND filters.

If you have ND filters of strength 1-stop and 2-stops, for instance, you could simulate the manual power levels "1/2" and "1/4" by letting the fire flash at 1/1 power but holding the respective filters in front of the V6's sensor.

The next question is whether the flash will recycle quickly enough because the V6 allows increasingly less time for lower power levels in order to cut down on the whole profiling time...

I don;t think that can work accurately.

profiling a flash is surely t.1 times and how the xenon tube reaches full brightness and tails off, This will vary depending and tube, power and quench circuitry

Covering the v6 sensor or flash head to 'simulate' this will not work you'll just profile the flash 3 times fro full 1:1 outptut and create a profile that has no reference to what will happen when you quench the output.

so you'll get multiple output levels that are not 1, .5 , .25 at all but some random level that neither you or the triggers has any idea of, This may not be a problem for 1 flash remote use but if your using multiple flashes of 1 trigger or multiple flashes balanced will be a disaster.

[Class A]

Great review , Just a quick question

Thanks!

Does the V6 alllow full P-ttl pass thru.?

Yes, for Canon, Nikon, and Pentax but only for a V6 that sits on top of a camera.

i.e can I put a 540 ontop of it and shoot p-ttl as if its not there ?

Yes, as long as the V6 itself sits on the camera.

In other words, there is no radio transmission of P-TTL signals.
Only power levels and trigger signals are transmitted, so to speak.

Your review implies it will not work due to non center pin triggering but neither the Nikon or Canon use center pin triggering for their solutions and it seems they pass through.

Where does my review imply that P-TTL pass-through won't work?

I'd be grateful if you could let me know where and how I seem to be miscommunicating.

Indeed, for remote control of power levels, the receiver V6 uses more pins than just the centre firing pin, but this has nothing to do with P-TTL pass-through.

It works but I'm often left wanting to alter the flash ratio during a shoot but can't change the 45's without visiting each of them

As you say, the Metz 45s should work with the V6. As long as they are for the Canon, Nikon, or Pentax system and support TTL, you should be able to create your own flash profile for them.

There all capable of TTL so should be controllable from the V6 trigger.on the camera, providing full pass thru is implemented my P-ttl flashes will be unaffected

As I said, only a P-TTL flash on-camera (with a V6 between the flash and the camera) will benefit from P-TTL pass-through.

The other P-TTL flashes may also support remote power control via V6 radio signals (depends on whether they are already supported or support user profile generation through analogue TTL support).

[Class A]

I don;t think that can work accurately.

Believe me, it will work as long as recycling times at 1/1 are not too long.

I haven't measured the assumed recycling times in the reference level phase yet, but they become increasingly shorter, the lower the reference power levels are (in order to speed up the whole profiling exercise which only takes ~5min. this way).

profiling a flash is surely t.1 times and how the xenon tube reaches full brightness and tails off, This will vary depending and tube, power and quench circuitry

For the (manual) reference levels, the V6 only needs to measure the overall light output (the integral over the curve you describe) for a given time (perhaps 1/100s?).

Using a one-stop ND filter in front of the flash or in front of the V6's sensor will thus simulate 1/2 power level.

The actual curve of the flash output should not matter at all at this point.

Later, in the "learning" phase -- when the V6 figures out how to imitate the reference levels by using the quench pin -- the actual output curve matters, but you are not using any ND filters at this stage anymore.

so you'll get multiple output levels that are not 1, .5 , .25 at all but some random level that neither you or the triggers has any idea of,

You will not get random levels, but a valid flash profile.

Meeting the recycling time requirements could be a major hurdle, though.
Someone should try this, or I should somehow find the time to at least measure the expected recycling speed at 1/4 power level (the fastest that is absolutely needed).

[awaldram]

Thanks!


Yes, for Canon, Nikon, and Pentax but only for a V6 that sits on top of a camera.


Yes, as long as the V6 itself sits on the camera.

In other words, there is no radio transmission of P-TTL signals.
Only power levels and trigger signals are transmitted, so to speak.


Where does my review imply that P-TTL pass-through won't work?

I'd be grateful if you could let me know where and how I seem to be miscommunicating.

.

Thanks your reply is exactly what I was hoping

What implied to me was bottom of 'optical triggering ' you say

", Canon/Nikon users can also put such a system-dedicated trigger (supporting E-TTL/i-TTL respectively) on top of a V6 in TTL pass-through mode and thus not only forgo the sync cable but also combine manual flash levels with TTL automatic exposure. No such system-specific triggers exist for Pentax, though."

Read more at: Cactus V6 Review - Further Special Features - Pentax Camera Forums

As I wish to combine manual flash levels with p-ttl automatic exposure you seem to be saying it can't be done with Pentax .

---------- Post added 13-05-14 at 09:32 AM ----------

Believe me, it will work as long as recycling times at 1/1 are not too long.

I haven't measured the assumed recycling times in the reference level phase yet, but they become increasingly shorter, the lower the reference power levels are (in order to speed up the whole profiling exercise which only takes ~5min. this way).


For the (manual) reference levels, the V6 only needs to measure the overall light output (the integral over the curve you describe) for a given time (perhaps 1/100s?).

Using a one-stop ND filter in front of the flash or in front of the V6's sensor will thus simulate 1/2 power level.

The actual curve of the flash output should not matter at all at this point.

Later, in the "learning" phase -- when the V6 figures out how to imitate the reference levels by using the quench pin -- the actual output curve matters, but you are not using any ND filters at this stage anymore.


You will not get random levels, but a valid flash profile.

Meeting the recycling time requirements could be a major hurdle, though.
Someone should try this, or I should somehow find the time to at least measure the expected recycling speed at 1/4 power level (the fastest that is absolutely needed).

Ah I understand profiling is done after assessing what 1/2 , 1/4 power looks like .

---------- Post added 13-05-14 at 10:14 AM ----------

Hi Class A

Unless I missed it your review does not point-out the 'pass through' is a selected operating mode of the transmitter and not a hard wired socket-socket this explains at least to me that this unique feature is somthing that I can use.

From the manual

TTL Pass-through
The V6 transceiver comes with a multi-system shoe that supports TTL pass-through.
While the V6 does not transmit TTL signal wirelessly, it is designed to pass TTL signal from camera to flash via the transmitter (TX) and vice versa.
The multi-system shoe supports TTL pass-through of Canon, Fuji film, Nikon,Olympus, Panasonic, and Pentax systems.
Make sure that camera and flash unit belong to the same TTL system.
With TTL pass-through, the TTL flashes behave as they would when directly connected to the camera hot shoe. The V6 will work as a wireless flash commander while supporting all the automatic features (e.g., automatic flash output via TTL metering, AF assist light, second curtain sync, high speed sync/FP shutter) provided by the TTL flash system.

To enable TTL pass-through in the V6 TX, press and hold for 2 seconds. The LCD will show the TTL pass-through indicator at the left bottom corner where the channel indicator used to be.
In TTL pass-through mode, the V6 TX cannot control the power level of the flash attached.

To disable the TTL pass-through mode, press and hold for 2 seconds. The TTL pass-through indicator will be replaced by the channel indicator on the LCD.

http://www.cactus-image.com/Cactus%20V6%20User%20Manual%20%28EN%29.pdf

[chickenandavocado]

i have a sigma 610 dg super which isnt a preinstalled profile / officially supported for pentax on the v6

i am wondering in terms of "learning" the flash's profile, is there any limitation/ anything i am missing, compared to the official pentax flash (that is supported)? or are the "pre installed" profiles for supported flashes basically set up after doing similar "profile learning'? (e.g. cannot change power level wirelessly)

[Class A]

i am wondering in terms of "learning" the flash's profile, is there any limitation/ anything i am missing, compared to the official pentax flash (that is supported)?

If the V6 can create a profile for the Sigma 610 DG then the latter will receive the same support as a predefined flash (e.g., the AF540FGZ).

Whether the V6 can create a flash profile depends on four prerequisites:

1. The flash must be designed to work with a Canon, Nikon, or Pentax camera.

2. The flash must supports analogue TTL (also referred to as " film-based TTL" or "film-style TTL"). Your Sigma 610 DG Super ticks that box.

3. There must be at least two standard manual levels below "1/1" power, e.g., "1/2" and "1/4". The more standard levels are available as manual levels, the better for the accuracy. It seems your flash supports 1/1 down to 1/64, so all good here as well.

4. The last prerequisite is impossible to tell from a specsheet, because only by attempting to profile a particular flash, you will find out whether the V6 can "talk" to the flash to make it output various power levels. Even within one system, say Pentax TTL, there can be a number of communication variants that the V6 must master in order to coax the flashes into producing desired output levels.

Unfortunately, some Sigma flash models are known to be capricious. For instance, the Sigma EF-530 DG ST for Canon cannot be fired with a standard radio trigger. Unlike the vast majority of flashes, it requires digital communication with the camera before it enables the centre-pin firing.

Once a V6 user base has built up, it will hopefully be possible to collect information about which flash models proved to be compatible with the V6. I expect a lot of flashes to work with the V6 through user-defined profiles, but there will probably be exceptions.

If the V6 can communicate with a flash (it could with all TTL flashes I had available) then it can create a profile that can be used as if it were a predefined profile. You'll then be able to remotely control the power level.

P.S.: The profiling prerequisites are also described in the custom profile section of the Cactus V6 review.

---

Last edited by Class A; 05-13-2014 at 08:37 AM.

[Class A]

What implied to me was bottom of 'optical triggering ' you say...

In hindsight, is it now clear that in

"No such system-specific triggers exist for Pentax, though."

the term "system-specific triggers" refers to P-TTL capable triggers (e.g., from Yongnuo, Phottix, PW, etc.)?

All V6 are the same, there is no brand-specific version. The problem is that on a Pentax camera, the only way to get a pre-sync signal is to use a P-TTL flash connected to the camera. The alternative of using a P-TTL capable trigger is not available for Pentax (only for Canon, and not needed for Nikon).

As I wish to combine manual flash levels with p-ttl automatic exposure you seem to be saying it can't be done with Pentax .

It can be done in a limited way.

The only P-TTL automatic exposure support would be for a P-TTL flash connected to the camera (either on top of a V6 in TTL pass-through mode, or directly connected to the hot-shoe, with the V6 being triggered through a sync cable connected to the camera).

Unless I missed it your review does not point-out the 'pass through' is a selected operating mode of the transmitter and not a hard wired socket-socket this explains at least to me that this unique feature is somthing that I can use.

I use "mode" and (I think) "engage", etc. in the review when referring to TTL pass-through.

The pass-through feature certainly works -- I tested it -- but only for an on-camera flash that has the V6 sandwiched between the camera and itself.

[panoguy]

The only P-TTL automatic exposure support would be for a P-TTL flash connected to the camera (either on top of a V6 in TTL pass-through mode, or directly connected to the hot-shoe, with the V6 being triggered through a sync cable connected to the camera).

And, of course, any V6 triggered flashes set to manual levels will not be included in the P-TTL exposure calculation, so it could be pretty easy to overexpose things. I've already run into this...

[Class A]

And, of course, any V6 triggered flashes set to manual levels will not be included in the P-TTL exposure calculation...

Good point.

Flash exposure compensation for the P-TTL flash may help to some extent, but there is not much range...

I've already run into this...

Are you using V6?

Would be cool to be hearing from you about your other experiences.
I did only a few real world shoots, most of my time was spent on systematic testing and measurements.

[awaldram]

In hindsight, is it now clear that in

"No such system-specific triggers exist for Pentax, though."

the term "system-specific triggers" refers to P-TTL capable triggers (e.g., from Yongnuo, Phottix, PW, etc.)?
.

Ah , I use brand agnostic radio flash controllers so when you said 'trigger' I think center pin, edge, analogue/digital trigger i.e the protocal used to trgiger the flash not the physical wirelss flash module.

Hence I read it as
No Such
System specific ie P-TTL
Triggers ie protocol
exist for Pentax.

as to mixing p-ttl with manual I do that today

My metz are set auto or manual minus x stops by setting ISO below camera by the desired offset.

The P-ttl is fired wirlessly optical or RF upto 7 flashes in use
the Metz upto4 are fire via the pc with simple single pin wireless controllers

The V6's would allow me to controll the manual ratio without messing with the flashes which are often not accessible during the shoot.

I'm constrained in aperture due to the Metz settings being able to remotley controll them will free me.

---------- Post added 14-05-14 at 09:18 AM ----------

Good point.

Flash exposure compensation for the P-TTL flash may help to some extent, but there is not much range...
.

But that is the point, having unmetered light at shutter time gives you controll of both the p-ttl flash and the ambient (manual flashes)

Without it you have to live with the ambient either blow it out or reduce flash to include, with manual flashes I can alter both image focal and surrounding light levels.

I effect providing the finer control than 'grouping' will deliver.

[chickenandavocado]

they're back in stock at gadgetinfinity... put an order through and will see if my sigma 610 works.

thanks class a for all your feedback and the detailed review.

[Class A]

... put an order through and will see if my sigma 610 works.

It would be cool if you report on the outcome of the test.

I've started to collect compatibility reports.

thanks class a for all your feedback and the detailed review.

No worries.

[rawr]

they're back in stock at gadgetinfinity...

Excellent news. Just ordered one myself.

The availability of an X-sync port on the v6, and also the ability to act as a high trigger voltage 'safe-sync', will be of particular value when using flashes like my early-model Metz 45-CT1 directly off the camera.