[mcgregni]

Thanks for those further points about mixing modes with radio systems .... I'll try and add something about that option, although it would seem to be for the advanced and experienced user.

Pentax's 'ratio' control system ('Contrast Control Sync Mode') is a bit of a minefield! So much so that I avoided it in the first versions of the guide. The earlier flash model manuals give the impression that it applies only to extension corded flash use. The more recent MkII manual does not suggest that and seems to refer to it equally as valid for wireless operations as well. This frankly needs testing and more exploring.

Firstly, I have no idea why it is called a 'sync mode' ... ? It appears to be really a form of proportional power output control. The new manual specifies that by default an on-camera unit will emit 1 half of the power of a single off-camera unit .... this presumably is until the user dials in another fraction, but this is not discussed at all in the manual !!! The explanation of practical working with this feature is really poor, in fact there's no practical working explanation to speak of. So we really are making it up as we go along, or relying on experienced users to help. I would like to deal with this feature properly in the guide, but that depends of any further information being given here or on my own testing to come.

But I agree with awaldram that the camera-set flash compensation amount is applied to the entire exposure value for the whole scene, and that any flash compensation settings on the flash units are then added or deducted (in stops) to that total EV. So we have a nice easy means to control overall flash brightness from the camera.

If the contrast control sync works as it should then the ratios as set on each flash will divide the total flash EV into parts, each part to be emitted by the individual flashes as specified ..... so for example, 1 flash will emit 1/3rd of the total flash exposure value, and the other one 2/3rds. Changing the camera-set FC will alter the total flash exposure whilst maintaining the proportion of the total emitted by each unit.

I have no idea what happens if the user sets illogical ratios, eg 2/3rd on three units !! ?? Also we don't seem to have any definitive information on the difference in practice between setting FC levels (in stops) and ratios at the same time .... they are both available simultaneously on the flash displays ... ? If we can come to a greater understanding of these matters then it may well be that complex multi-flash wireless P-TTL flash control might well become far more convenient and reliable .... ??

---------- Post added 09-14-15 at 06:42 PM ----------

....

As a Point on Pentacs silly 'fill' ratios I believe Nikon skirt this with two modes in itll
1 TTL Normal flash as you'd expect from a P&S (flash ignores ambient , camera adjust exposure for flash only) this is what Pentax does in 'X'
2 TTL-BL Balanced lighting flash output is reduced to match 'bright' ambient conditions this is what pentax does in Green,P,Av,Sv,Tav etc etc

Is some of this covered by the 'slow-speed sync' camera flash mode ? In auto-flash mode then we get time values set to maintain shake free images, ie not balanced for ambient .... but switch to 'slow-speed-sync', and even in the auto-exposure modes then the time values are free to go as slow as needed for correct ambient and flash balancing, even in low light..... ?

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Last edited by mcgregni; 09-14-2015 at 10:43 AM.

[Class A]

Every Pentax P-ttl flash offers at least 4 stops control and I believe the new version more.

Well, some cameras only offer -2 to +1 EV of flash exposure compensation. Even if it is a bit more, it will often be not enough.

Worst, the compensation is always with respect to a global level that can be influenced by anything in the scene, such as a bride with a white dress moving forward a bit. Do you really want your background light level change because of that?

This is exactly the same as CLS but without grouping and remote access.

Well, grouping and remote access are rather significant features.

CLS furthermore supports defined lighting ratios between flashes. There's probably more, frankly, I don't care, as I would never want to fight any automated exposure system, no matter how advanced it is. Anyone stating that Pentax's flash system is in dire need of an overhaul, is not wrong, though.

i.e you cant say Nikon CLS is the bees for multi flash set-up and Pentax is rubbish when Pentax offers the same functionality (but having to address the flashes rather than remote control)

Well, first I disagree that they offer the same functionality. Next, I never said Nikon CLS is the bee's knees. I only said it is a lot more advanced than P-TTL, which it is.

[Class A]

On intelligent wireless (i.e cactus V6) you can set each RX to be in a group then control that groups output remotely with only one setting so this makes altering contrast control easy from the camera , But you can't easily alter the overall level with out having to turn each group down the same amount.

Not true. I wonder why you believe that, given that you own Cactus V6 units.

Simply turn the dial with any number of groups being active. They will all change by the same amount. There's your global control. Picking out one group is easy by turning the dial while keeping that group's button pressed (or by permanently making it selected with a long-press on the group button).

[Class A]

We will all take up defensive stances for the approaches we have personally chosen. We are naturally biased towards our own approaches and probably had negative experiences of the things we didn’t choose finally.

True, however, there are also facts and objective differences.
Each shooter must decide for themselves which of the trade-offs works best for them, sometimes even depending on a particular shoot.

Of course, you know that, otherwise you wouldn't bother to add some kind of comparison to your existing guide.

Now, about definitions. You won’t find me describing the Pentax flash system as ‘P-TTL’. It has been often termed this, but I avoid it because frankly it is a lot more than this! To me, P-TTL is just one single flash exposure mode that is always available on a Dedicated system flash.

I understand that a dedicated flash offers everything a manual flash does, plus P-TTL and that you don't want to create the impression that dedicated flashes are limited to P-TTL.

However, what do you want to compare?
It does not make sense, AFAIC, to compare Pentax (or system-dedicated, in general) to generic, as the only difference is the option of P-TTL and its associated features. Non-dedicated flashes often also have multi- (strobe) modes, A-modes, etc. So once it has been established that a dedicated flash has other modes as well, it really boils down to whether one wants to make a considerable extra expense for the P-TTL features. That's why I have been treating this as a "manual vs P-TTL" discussion, not as a "generic vs system-dedicated" discussion. The latter distinction would only make sense to a manufacturer trying to sell dedicated equipment; beyond that I don't see a point in this categorisation.

This could be described better, accepted. I mean that you can go online or into a shop and buy a Pentax flashgun, or a Metz or Sigma that are ‘For Pentax’, and you know that you can just put it on the camera and switch on and it all works.

A manual flash will work straight out of the box as well.
Same with a radio trigger. Most are so simple that there isn't even much to configure.

A Cactus V6 may require you to select the correct flash profile for your flash, however, that's comparable to configuring your system-dedicated flash so that it gives you the results you want.

There are only a few triggers that require a bit of attention, e.g. some older Yongnuo units, that will only sync up to 1/160s unless you employ workarounds, but these are the exception.

I'd say the non-dedicated equipment is simpler to use and works "out of the box" just the same as dedicated equipment.

It is not the same simple process for choosing a radio system. As the vast number of threads asking questions about the matter demonstrate, it requires more research and understanding of the particular requirements and features of each system – do they need hot-shoe adaptors, separate triggers, cold-shoe devices to function etc.

Again, none of what you mention as a complication applies to the vast majority of equipment. Most triggers don't need any kind of attention, just batteries, and many recent flash models have them built in already, so you don't even need batteries.

I meant in relation to the simple scenario with the built-in that it was a quick and fairly easy way to get wireless flash going, in combination with one or perhaps two off-camera dedicated flashes without having to also set up a radio trigger.

Yes, it is a quick way to get off-camera flash going, but as soon as you deviate from straightforward scenarios, the challenges start.

Would I be right in assuming that once the channels are configured on a radio system that it is all remembered and so you don’t have to make all the settings again each time?

Of course, you don't have to make all the settings again each time. And you don't have to "configure" the channels either. If you leave everything at default values, the triggers will work. Changing channels is only required if you are near a photographer using the same system (or have some kind of rare radio interference).

BTW, it is not common for beginners to ask how to synchronise the "wireless" channel on a P-TTL flash with the camera. So there may even be more effort involved when using dedicated equipment. Also, I've read that the AF 540 forgets a number of its settings when you turn it off. The RF60 and V6 don't do that and thus allow you to pick up your shoot where you left off last time.

In practice indoors the optical communication system signals will reflect and bounce around meaning that it is rare for you to need absolute direct line-of-sight.

Yes, optical triggering works in a range of scenarios, but if you start controlling your light some more so that it doesn't spill around the whole room and/or have your receiving flash units in less than ideal positions for optical triggering, things can become challenging. Joe McNally sometimes uses a dedicated flash, attached to the camera via a cable, with its own stand just as an optical trigger, to get more reach and control over the direction. That's insane effort, AFAIC, compared to putting a small transceiver on the camera.

I’m not able to agree with ClassA that dedicated wireless systems only work well with a single off-camera flash. I have found my two Pentax flashes to work very well off-camera, triggered by the built-in flash, and it is easy to control lighting ratios both with P-TTL flash compensation and full manual flash exposure mode.

What kind of lighting ratios are you able to achieve per individual exposure compensation?
How easy is it to use one flash as a key light and the other as a rim light with power levels appropriate to their purpose?
Do you really want the rim light level to change when the model turns their head, causing the key light to be adjusted automatically?

I do not dispute that a simple two light setup is easy to achieve with P-TTL but I maintain that such simple setups will give you rather boring lighting and are hence not worth bothering with. A beginner can take "correctly" exposed snaps this way, but I'm unconvinced that this is an efficient way to achieve interesting and creative lighting.

Full manual provides the same reliable and consistent exposures as manual output settings on radio triggered flashes … there’s no reason they would not.

Of course, the triggering approach does not influence the consistency of exposures.

However, any automatic exposure support (P-TTL, A-mode, ...) will respond to changes to the scene, be it ambient light changes, someone with bright clothing moving, something reflective being revealed by a moving person, etc. So automatic exposures will always imply varying exposures that are less efficient to deal with in post-processing.

Again, I don't think it makes sense to claim that a dedicated system is the best, as it gives you the manual and the automated choices. The question should be "What are the trade-offs between manual and automated flash level control?" and the fact that some (much more expensive) equipment can do both manual and automatic is secondary. Once one establishes that one has a need for automatic flash level control, one chooses a system that supports that. If one can live without such support, one can save a lot of money and may even get more convenient and efficient control over lighting (using groups and remote power level adjustments).

Look at the banks of cameras and flashes at sports events, political speeches, outside courtrooms etc …. I doubt that you would see the name Cactus or Yongnuo sitting on top of many of those professionals cameras.

Most of these location shoots do not involve off-camera lighting because it is not feasible, so trigger systems are not required.

Consider Academy Awards or similar, though, and you'll find professional photographers using off-camera flash, almost invariably using radio triggering. Whether the trigger brand is PocketWizard, Cactus, or Yongnuo, does not matter. They all do the job. BTW, the PocketWizard company, a traditional "professional choice", has been in financial trouble for a while now. They did not innovate enough for the very high prices they were charging. Expect to see more professionals to use Phottix, Cactus, etc. in the future.

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Last edited by Class A; 09-15-2015 at 01:22 AM.

[awaldram]

Well, some cameras only offer -2 to +1 EV of flash exposure compensation. Even if it is a bit more, it will often be not enough.

Worst, the compensation is always with respect to a global level that can be influenced by anything in the scene, such as a bride with a white dress moving forward a bit. Do you really want your background light level change because of that?

That is 'on' camera nothing todo with 'on' flash
On camera offers flash compensation for the 'global scene' 'on' flash gives ratio control for each individual flash

---------- Post added 15-09-15 at 10:13 AM ----------

Not true. I wonder why you believe that, given that you own Cactus V6 units.

Simply turn the dial with any number of groups being active. They will all change by the same amount. There's your global control. Picking out one group is easy by turning the dial while keeping that group's button pressed (or by permanently making it selected with a long-press on the group button).

Ooops thats usage over reality sorry.

---------- Post added 15-09-15 at 10:19 AM ----------

Most of these location shoots do not involve off-camera lighting because it is not feasible, so trigger systems are not required.

Consider Academy Awards or similar, though, and you'll find professional photographers using off-camera flash, almost invariably using radio triggering. Whether the trigger brand is PocketWizard, Cactus, or Yongnuo, does not matter. They all do the job. BTW, the PocketWizard company, a traditional "professional choice", has been in financial trouble for a while now. They did not innovate enough for the very high prices they were charging. Expect to see more professionals to use Phottix, Cactus, etc. in the future.

One excellent use of groups in a very simple function is when you have multiple venues with short time frames (say wedding + register signing) you can pre-set up your falashes say zones A+B for wedding then C+D additional unit for the register signing.

So on the shoot you can enable A and B during the wedding then C and D for the book signing.

This could also be done under Nikon CLS but not Pentax P-ttl wireless system.

One other issue I've had with P-ttl optical firing is random firing when in group situation with other non-pentax camera flashes specifically in my case Olympus dslr's

[mcgregni]

Thanks again ClassA and awaldram for that feedback, which is contributing to a most constructive discussion. A lot of what you say will help me to remove even more possible bias in the facts and features that I will end up describing in the guide. I think I will start to draft up a few passages that I intend for the guide and float them up here for you all to consider .....

[Class A]

May I add that I just had a browse through the "Pentax Flash Guide - 1st Development Thread" thread and came away with the thought that "works out of the box" does not really apply to P-TTL in general.

There are many camera bodies that have P-TTL bugs and while A lenses will mostly work OK for some bodies (but not without issues for the K-3), for full P-TTL accuracy at least F-lenses are required, but even then there is no guarantee.

I'm not saying that P-TTL compatibility is a minefield, but there are some issues to be aware of and some potential incompatibilities one would not expect.

[mcgregni]

This issue of what works 'out the box' seems to come into the personal individual needs category. I will avoid making any suggestions that technically and connection-wise any one system works more easily than the other, and I will be guided by your points, ClassA, that the radio manual systems are generic and don't require any more "configurations" than a dedicated flash set-up.

My own thinking on this is that in reality, shopping for and then starting to use a dedicated system flash, is not dissimilar to buying a DA lens ..... You know it will fit on and communicate automatically with the camera. A modern dedicated flash is the same .... It fits on and is electronically coupled to the camera, and by extension through the mechanical aperture coupler to the lens as well. This means that camera/lens/flashgun combo communicate and work as one, in many respects. It is this connecting of items into one that gives the auto-exposure feature and the range/distance indications, as the flash 'knows' the camera settings.

A radio manual system works differently, in that it does not communicate and connect to the camera in this way and does not use the camera aperture and ISO information (plus shutter for HSS) .... It remains contacted in a more basic manner and functions mostly as a standalone system working in tandem with the camera.

Now this extra connectivity and communication in a dedicated flash is used mostly for P-TTL working, plus the auto-flash head zooming, but it is also used in Manual exposure mode to continuously update the flash to subject distance indicator. There is a workflow description for manual mode shooting using the distance indicator already in the guide, so I see this is a distinct advantage of the dedicated flash, even in manual mode when you can be harnessing the consistency and reliability of manual flash exposure, BUT with the added guidance of a constant references to correct subject distance which responds to every aperture, ISO, flash power and flash head zoom input! It's really great .. Best of both worlds .... And not available on a third party radio system.

Most of the negative points that have been raised here about Dedicated system flash are in fact really about the P-TTL flash exposure mode. Of course I am going to respond to that and describe in the guide where there are inconsistencies and variables with P-TTL exposures ....all the work on the other thread is exactly about that. But beyond that the other aspects of dedication, the added connectivity and communication to the camera and lens, are mostly positives, and offer a clear advantage to the issue of how to take advantage of the fully reliable and consistent manual exposure mode, but in more dynamic situations or where P-TTL can be too inconsistent. The distance indication is key to that practical workflow.

P-TTL is just one useful feature on the multi-purpose versatile dedicated system flashgun, and the purpose of the guide is to help users understand all the choices and options available and to pick the best combinations in the right situations .... This extends to the camera custom settings as well and the miscellaneous features, all of which are covered. The newest flashguns add in the LED light for catchlight, front fill, video and AF assist, all of which will be added into the next edition of the guide.

At the same time as summarising all of the dedicated system features I will also be describing the significant features of radio manual alternatives, including of course their better value (that's much cheaper!) and advantages for multi-unit and more complex set-ups with easy power control in groups and in total. The dedicated flashes are more multi-featured units, more expensive as a result, but great value for many photographers who need to switch from one type of flash work to another.

The other day I had my two AF540s off -camera, one in a softbox and the other on a stand, shooting portraits with a black background and a little front fill from the diffused pop-up flash .... In manual exposure mode and manual flash exposures ..all totally consistent and perfectly balanced and reliable, as manual mode always is.

Then, one daughter wanted to jump on the trampoline in bright sunshine, so straight away the AF540FGZII was off the stand, onto the hotshoe and into HSS mode .... Shutter speed to around 1/1000sec in M mode, click flash and I was getting lovely ambient and flash balanced shots with her caught frozen suspended in mid air! Great flash versatility and functioning in a single great value flashgun!

[Class A]

There is a workflow description for manual mode shooting using the distance indicator already in the guide, so I see this is a distinct advantage of the dedicated flash, even in manual mode when you can be harnessing the consistency and reliability of manual flash exposure, BUT with the added guidance of a constant references to correct subject distance which responds to every aperture, ISO, flash power and flash head zoom input!

Note that all this only works if the flash head points forward and you do not use bouncing or a light modifier. Hence, this functionality is only supporting the most horrible of all flash usages, i.e., direct flash. The unflattering highlights and hard shadows that result from this way of using a flash should be avoided if in any way possible.

[mcgregni]

, But the usual mental adjustments would be made for diffusers where the light loss would be known in advance, and quick bounce allowances can easily be factored in, like ' plus 1.5 stops' Again, this is another example of the dedicated flash being used on - camera for faster changing situations, and is an extra source of guidance to the intelligent use of manual mode.


Just because the feature only works when the flash head is straight and direct doesn't mean it only supports flash without bounce or diffusers ... It is one more piece of information to aid quick and efficient manual flash operation. Just point the head at the subject, note the power needed, then flick to the bounce position and dial in your bounce factor.

[CarlJF]

But I agree with awaldram that the camera-set flash compensation amount is applied to the entire exposure value for the whole scene, and that any flash compensation settings on the flash units are then added or deducted (in stops) to that total EV. So we have a nice easy means to control overall flash brightness from the camera.

This remind me that the interactions between EV, on camera flash EV and on flash EV is something that I would really like to see clearly explained somewhere. Official informations from Pentax on these seem scarce and hard to find, supposing they even exist... For example, if I set +1 flash EV on the camera body and +1 on the flash, would I get +1 or +2 from the flash?

Also, it seems that at least some of these settings will behave differently if the flash is on camera (or off with a cable) or in wireless mode. Which is quite puzzling when you're trying to figure out what can be wrong with your flash setup. For example, EV compensation will affect the flash when use on camera but not in wireless mode. At least, this is what I observe with 360 and K-500...

So, it would really be useful to put these information somewhere in your guides. Which settings (EV, on camera flash EV, on flash EV) affect what, are they additive or not, and do they work the same on camera and wireless.

[mcgregni]

Thanks for raising that aspect of it. I'll take a closer look and try and add more clarification. There is only brief reference to the separate camera and flash compensations at present, so you're right that it could do with some expansion. I'll look at a section in the Flash and Ambient exposures part.

At its simplest then yes, the camera set and flash set compensations will accumulate mathematically, but the wireless combinations need more exploration. In master mode the on-camera FC will apply only to the on-camera unit, but in control mode then it applies to the global flash exposure. I will look into this further as I also want to deal with the contrast control sync mode for proportional output control. It will be interesting to see how this interacts with the camera flash compensation in control mode ....