Originally posted by beholder3 It is true in general. High-Speed-Sync "HSS" is a defined thing within all x-TTL systems
You can deny this but
- People and some companies use "HSS" in a broader sense, including any use of flash beyond the sync-speed. You can argue that this is "wrong" and I'd agree, but it happens. It simply isn't true that if you read "HSS" that it always means TTL-based HSS.
- It makes sense to refer to "HSS" flash photography as long as the flash issues a very fast series of light bursts in order to approximate a continuous light output. It is not essential, that the correct timing is achieved via a TTL protocol. For instance, with a Cactus V6 I can release the camera and the flashes at the "same" time (the flashes need to be delayed) and thus achieve HSS light (i.e., practically continuous) output without involving any expensive P-TTL equipment.
So yes, technically in the context of using a Pentax DSLR, "HSS" only refers to "P-TTL HSS", but you cannot depend on every occurrence of "HSS" to mean "TTL-based HSS" and while some of the deviations are examples for loose talk (as they really mean HyperSync/Supersync), others are valid as they still refer to the correct light output technology but simply do not require TTL.
Originally posted by beholder3 It can not exist without TTL.
That is only true with a narrow definition of "HSS".
If you include other forms of triggering the same light output then "HSS"-lighting is possible without TTL.
For instance, you can trigger many non-TTL RF60 in HSS mode by just using one P-TTL on-camera flash, or by triggering the camera and flashes remotely at the "same" time (thus not using any P-TTL equipment at all).
Originally posted by beholder3 Then there are a number of makeshift workarounds to simply achieve "Supersync" speeds.
SyperSync/HyperSync is not a workaround, it is a different technique.
Many lights are not capable of generating a fast series of bursts that approximate continuous light (HSS style light output). However, they can "burn" long enough with just one pulse to still illuminate the full frame.
Neither lighting technique is a replacement for the other, they are just two different ways to take the shutter speed beyond the sync speed and still get the whole frame illuminated. Since they are tied to the technology of lights, it makes sense to distinguish them independently of how the triggering works. Hence my argument to not use "HSS" only in conjunction with a certain triggering technology.
Do you have a suggestion how to call "HSS"-style light output to distinguish it from "SuperSync"-style light output without implying a triggering approach?
Originally posted by beholder3 The typical camera user with a single pocket flash unit will value the ease of use of a TTL flash system (that is why it's everywhere in the better flashes).
Whether they are "better" flashes, is debatable.
They just support exposure automation. A point and shoot camera with exposure automation is not necessarily better than a manual camera. Likewise, a manual flash could be better in terms of recycling rate, power output, additional features, and value for money.
Originally posted by beholder3 The few people who use multi (studio) strobe setups who define the individual power output personally anyway use Supersync (plus the ones who don't have the money for better pocket flashes).
There are also many who have the money for more expensive TTL solutions but simply don't want to waste it on (automatic exposure) functionality they don't need. These people know how to get the correct flash power very quickly and enjoy the much more predictable and consistent output of manual flashes instead of fighting the quirks of automatic exposure. I trust you know David Hobby (running "The Strobist") and his philosophy on flash photography.
Originally posted by beholder3 Anyhow the acon R930 is currently the most advanced flash transceiver system we can get for the Pentax system.
I dispute "most advanced".
- The Aokatec triggers achieve the same functionality and just require a more clunky setup. We probably agree that they are bulky and cumbersome to set up, but in terms of functionality they are just as "advanced".
- The P-TTL support added by Aokatec and Acon triggers is not very useful for multiple off-camera flashes. The P-TTL system is simply too outdated to be useful for any but the most simple lighting setups. The nice upshot of getting P-TTL support is HSS triggering and second-curtain sync triggering.
- There is other advanced functionality, that is not supported by the Acon triggers. For instance, the Cactus V6 support remote control of power of individual flashes and/or the whole group, they support being triggered optically, they allow delays to be configured to achieve the second-curtain sync effect, or staged multi-strobing, or releasing cameras and flashes at the "same" time, or cameras at different times ("bullet time effect"), etc. They furthermore support a relay mode that allows you to configure the flash power and remote release the camera with one and the same trigger. They support group cycling which can be used to swap between normal and background lighting quickly ("mask generation") or alternate between up to four different flashes to achieve virtually zero recycling time, etc. Moreover they support a mode in which different flashes are calibrated to achieve the same absolute power output and can make older TTL flashes emit extremely short flash pulses (shorter than they can do natively).
So no, for some reasonable definition of "advanced" I don't think the Acon triggers are the most advanced.