K3 II - FPS in HSS

New member and first time poster (ever) I have a K3II and have just started learning HSS. I just perchased a Cactus V 60II trigger & RF 60X flash. Even though the camera is capable of 9 FPS when I try to use the HSS it seams to default to aproxemently 2 1/2 FPS is this normal or is there a setting that I am overlooking? Any input on this would be greatly appreciated !!
Thanks

Nigel is the one to answer, but from my understanding HSS uses a lot of power and can cause the flash unit to overheat. Are you sure it is not the flash that is the limitation? It needs to recharge.

i second that about nigel just about every one gose to him for words of wisdom

I agree with Peter (and stu!). I think he is right about the recharging being the limitation. Really, when you add flashes into the mix then you can pretty much throw quoted camera FPS numbers out of the window!

I'm no speed demon when it comes to flash, but from tests I've done with the similarly powered Pentax AF-540FGZ flash, I'd say that 2.5 secs recycling is not too bad really. And as Peter said, HSS can add to the power demands also. That was with an on-camera flash.

There might be limitations built in to the radio transmission system also, in terms of repeat triggering. The recycling will depend a lot of the power demands on the flash ..... What Aperture, ISO and shutter speed were you using for those HSS bursts?

Just had a look at the RF60 manual (I have the original model) and with alkalines it's rated to recharge from 'empty to full' in 5secs ..... That assumes fairly new batteries, so your 2.5fps (less than 0.5 sec to charge) looks good actually.

I wonder, if you want rapid flashing, perhaps you could try the 'multi-flash' mode, which fires a burst of flashes during a single exposure. You can choose the number of flashes and the gap between them. Great for moving objects.

Thank you for all the input. I had watched a YouTube video about this Cactus setup but it was with a Nikon camera (sorry didn't notice model #) and they were able to do bursts in HSS.
My limeted understanding of HSS is it can not do full power thus being able to flicker rapidly. I am only looking to get a burst of 4-5 frames.
So I am wondering if the camera has its own limitations.

Can you link to the video please

High speed sync takes a lot of flash power since the flash acts more like a strobe than a flash. Because of this, flash to subject distance will make a difference on the burst rate. The closer the subject, the less power required to illuminate the subject, then you get faster recycle time and higher burst rate. Until the flash overheats...

It's a limitation of Pentax cameras, pure and simple.

If you set your flashgun on your camera to say 1/64th power, then you should get 64 flashes before a recharge is needed.

If you do this you will still only get 2-3 fps, whether it's in manual or PTTL.

It was one of my pet peeves with the system and I never got an answer as to why the restriction was in place.

Unlocked, that's not correct, and the 'limitation' exists exactly the same on any camera system. Peter and Yves have clarified it further, as recycling is directly linked to battery state and power demand.

Photobook, I suspect you may be misinterpreting some aspects of what you saw being done .... It doesn't sound like you actually need 'HSS'. Could you explain in detail what you what to achieve with the flash, in terms of the actual images.

Thank you all!!
After hours of playing with the Cactus setup (I do love it) I have come to the same conclusions as Unlocker that it is the cameras limitation. It was very frustrating not to be able to find any info regarding this in my manual.
With the Cactus V6 II (trigger) turned off, attached to camera. Camera was able to fire 9fps.
As soon as trigger was turned on camera defaulted to 2.5fps thus bringing up my question rather I was doing something wrong or skipping a setting on the camera.

I also have a K20 and have not been able to achieve HSS. Has anyone have experience with the K20 & HSS?
THANKS FOR YOUR HELP!!!
Photobill

PS pschlute. Ill try to figure out how to attach video

I hope this is how you post a video.
Its a little long but if you want to skip to 3 min 55 sec you'll see the HSS burst.

https://www.bing.com/videos/search?q=cactus+v6+ii+video&&view=detail&mid=85C870B...

The camera detects when a flash is attached and on, or a an active trigger. When you switch it off then the camera performs as if no flash attached .... So you get the 9fps ...

With the trigger on then the recycling is limited by the trigger and flash systems. Power recycling is the main aspect, as has been explained. HSS is a technique mainly for balancing bright ambient light with flash, not for achieving rapid bursts.

Nigel, with every Pentax camera I had, I could never get the flash gun on camera to go at more than 2-3 FPS regardless of what was tried, it just wouldn't do it, it's a well known hardware limitation.

The burst you see at the end of the video is using two flashes together, there by halving the power demands so halving the recycling times. The shutter sounds you hear may not even be the actual live recording, it sounds overdubbed ..... In any case the flashes don't actually respond to every shutter sound, they only fire a few flashes, and they miss a good number of the shutter sounds, so it still looks like a 2fps or so speed of flash recycling.

If the camera is indeed able to keep firing at full burst speed in between flashes (as is implied by the sounds on the video), then there's little point id argue ..... There's no light on the subjects for those exposures, so they are wasted frames.

If this is the limitation you are referring to (ie the camera won't keep firing even though the flashes are recharging) then I don't see this as any sort of practical real limitation, apart from in the making of sexy cool promotional videos ....