Besides what you'll find in the description on the Pentax websites, hopefully superior quality to the non "*" lenses produced by Pentax.

Anyway,
- Water/dust resistant seals.
- Hypersonic motor for silent auto focusing (on K10Dand K100 super). Normal focus for everyone else.
- Quick-shift Focus System for instant switching from auto focus to manual
- A high price tag.

I would have suspected the pre-flash communications would be prior to the shutter. As a controller-only, the main flash would not be necessary as all settings regarding power and timing have been taken care of.

But you're right. It is the main flash that triggers the synchronized main flash from all the slaves. I never noticed that from the pop-up before even in reflective surfcaes because it is so extremely low power. he, he, I never photographed myself with the camera in the mirror using wireless flash, and no slaves, before.
But wouldn't ya know, a small beacon of light from the pop-up as well.

As they say... ya learn something new every day.

That is interesting. I know when in Control mode I do see reflections of the flash. I figured the flash simply did not diminish enough to be fully unnoticeable. But if it is actually performing some amount of main flash, that makes more sense with regards to what I'm seeing.
I just did not expect there to be any reason to do so.

Thanks

Slave 2 mode will cause the flash to behave as a dumb flash. In other words the flash will fire on the first light it sees.
The pop-up flash and any PTTL aware flash in the hotshoe will fire a pre-flash. This will cause the dumb slaves to fire, but no in sequence with he mirror being up.
Thee is no way to turn that off, but sometimes under certain conditions the slaves will be able to fire on both the pre-flash and on the main flash.

As Controller, the 540 in the hotshoe will fire pre-flash but will not fire a main flash. As Master, it will fire both pre-flash and main flash. So you might get lucky in Master mode.
If the 540 never even fired a pre-flash as the controller, then there is a problem. But I suspect if you step back and watch the flash you'll see it fire. (you just wont get any change in exposure on the final image.)

I have a dumb non-PTTL flash that I stick on the hotshoe and it will always fire the Slave 2 mode flashes every time. It also gives a bit quicker response since no pre-flash is done.. but of course then everything has to be set manually.


Anyway, glad that helped.
I change modes all the time, and have forgotten to switch on several occasions. Or I drop the flash in my bag while it is still on and by chance the modes get switched because something hit the buttons. It has become one of the first things I check now. Argh!!

Are all flashes set to slave mode 1? Hold the flash's backlight button for a few seconds.
Are all set to the same channel?

You say the "...2 real slaves fire... The 360's do not fire".
Do you have just the one 540 and two 360s? Or do you have other strobes?

Wow, those took a long time to load! It appeared that the links were not working. You just have to wait.

For anyone that wants to get these separately... (seem faster if you go there directly). The links are:
http://img-x.fotocommunity.com/66/1394866.jpg
http://img-x.fotocommunity.com/90/3843090.jpg


FYI, I cannot see #1 in either, but barely see #2.

That is great news! Great for me, not for my wallet!
Now, the important subject... Any ideas how I disguise the 50-135 as a kit 18-55mm lens so the wife won't suspect anything?

Yeah, depending on the distance, aperture and the lens, the difference is not noticeable. I don't remember if the lens and distance were mentioned in the article linked above, but I would have to guess that for most portrait work this is not an issue. In fact I'd be hard pressed to believe there would be a problem for the example given at that link.

I certainly have never noticed it myself (not that I have much experience in that arena, but still, I know if the final shot looks like crap)

But, for a recent photo I tried to do, I used a 50mm1.4 at about 18 inches. This gives a DOF of about .25 inches (.5 cm?). When focusing and recomposing on a point distance (on the same focal plane) 2 inches form the intended focus point you get a focal length that is about .1 inches longer.
If the physics holds true and the range of DOF is roughly 30% in front of the plane of focus and 60% in back, this .1 inch difference will cause the intended plane of focus to appear out of focus. Even at 50% either way, things may start to look unsharp.

In fact, this exactly matches what I saw in my recent attempt a couple of days ago. It took me a couple of tries to realize the arc being made during focusing and recomposing would make a difference at that level.

Unfortunately it is difficult at times for me to correctly determine the exact point of focus with the tiny view finder. I need to rely on the camera to do the work. For me, and possibly for others, it is an important issue to keep in mind when certain conditions exist.

For those with perfect vision, this is most likely an experiment in futility and would in fact be quite unnecessary.

Funny, just ran into this just the other day when trying to take a photo of some text with very small DOF (not quite Macro distances, but still close to the lense).
The slight change in angle while trying to focus and recompose just made it impossible to get a sharp image.
Took me a couple of tries before I realized what was going on. You just don't notice this with larger distances.