[theraven871]

I'll be brief.
I need off camera HSS that will work with a Pentax K5. What are my options?
I'm frequently shooting in bright sunlight and need to overpower the sun to fill in some facial shadows.

[bmw]

Two AF540FGZ's will do the trick: on on-camera, one remote. That much I know for sure as I've done it. Even with the remote one inside a small softbox, as long as it can see the on-camera one.

But if you are just doing fill you don't need HSS to do it. A regular reasonably high guide number flash, bare, especially if zoomed, and especially especially if not too far away, has enough guts to do that. And two of them ganged up in a softbox will do it with nicer light.

Folks get far too hung up on this HSS feature. I've not found it to be all that useful for normal shooting. It actually sucks up more power than just using the flash in a regular mode.

[theraven871]

I've had times when I've needed to shoot at F2.8 (ISO 100) and the pushed me up to over 1/180.
Its not that I WANT HSS, its that there are times I need it to shoot outdoors and under F5.6

[MPrince]

The price of HSS is reduced flash power. I would suggest you'd be better off using an ND filter.

[theraven871]

The price of HSS is reduced flash power. I would suggest you'd be better off using an ND filter.

I don't need strong flash power when shooting below F2.8.

I already have a set of ND filters. Yes they work.
But they destroy my entire work flow to have to bring them out and set the exposure correctly.
Off camera HSS would be a much simpler (and faster) route to take.

[mattb123]

Doesn't the new Cactus v6 support this with certain flashes? I'm not 100% sure but I think it may.

[manacho2005]

A $10 reflector will do the trick, also...

[theraven871]

A $10 reflector will do the trick, also...

Reflectors cause people to squint.


---------- Post added 07-14-14 at 04:30 PM ----------

I'm interested in the cactus V6. Can a cactus in the hotshoe trigger an off camera Cactus? (While leaving the on camera out of the exposure?)

Otherwise, are there any wireless transmitters/receivers for the K5 that support HSS?

[mattb123]

A cactus in the hot shoe can definitely trigger an off-camera Cactus. That is the primary function of these devices. I have v5 triggers and they do a great job triggering the flash, but the v5 is just a trigger. The v6 has more smarts and I think I read it will support HSS for certain flashes. I don't know the details offhand but I think there was a review on this site somewhere that might help.

[tuco]

... I would suggest you'd be better off using an ND filter.

How does a ND filter solve the problem?

[mattb123]

How does a ND filter solve the problem?

If done properly, it would let you shoot at the relatively slow 1/180 without overexposing when otherwise there would be too much light to do so.

[bmw]

How does a ND filter solve the problem?

It cuts down the amount of ambient light reaching the sensor by a few stops thus letting you use a wider aperture for a given shutter speed.

But it also creates a couple of new problems: the view is now really dark and focussing can be a big issue; and your flash needs to be pretty powerful to cut through.

However it can work and is a tried and proven solution.

[tuco]

If done properly, it would let you shoot at the relatively slow 1/180 without overexposing when otherwise there would be too much light to do so.

It cuts down the amount of ambient light reaching the sensor by a few stops thus letting you use a wider aperture for a given shutter speed.

But it also creates a couple of new problems: the view is now really dark and focussing can be a big issue; and your flash needs to be pretty powerful to cut through.

However it can work and is a tried and proven solution.

The ND also cuts down the flash strength. So I guess if you have flash power in terms of excess stops more to spare it could work.

[stevebrot]

I don't know the details offhand but I think there was a review on this site somewhere that might help.

IIRC, the Cactus units emulate HSS when used with a Pentax camera. There is no P-TTL exposure automation. Here are the pertinent reviews:

Cactus V6 Review - Introduction - In-Depth Reviews

Cactus RF60 Review - Introduction - In-Depth Reviews

A full read-through should be done to understand what these products will and will not do when used with a Pentax camera.


Steve

[Class A]

What the Cactus V6 will not do:

• Fake the presence of an HSS-capable P-TTL flash.

Unfortunately that means that one needs one P-TTL flash that is HSS-capable connected to the camera in order to get a trigger signal out of a Pentax camera if the shutter speed is beyond the sync speed (1/180s).

What the V6 will do:

• Optically trigger from either the main flash of the HSS-flash (worked fine up to 1/2000s for me) OR
  trigger from the pre-flash of the HSS-flash (works at any shutter speed, but requires manually dialling in a delay time -- something like 80ms -- to make sure the V6 does not trigger off-camera flashes too early).
• Trigger off-camera flashes with remote power control (no automatic exposure, though, flash power is selected manually on the V6).

The off-camera flashes need to have an HSS mode that can be engaged even if the flash is not mounted to a camera.

The Cactus RF60 is such a flash, and I believe the Godox V850 can do this trick as well. The latter won't support remote power control with the V6, though. The Godox V860C (for Canon) does, but I'm not sure whether it can be put into HSS mode manually.

Alternatively, one can -- as pointed out by bmw -- use Pentax's wireless (i.e., optical) triggering between P-TTL flashes. Drawbacks:

• Optical triggering is not ideal in bright sunlight.
• Line of sight required outdoors (ruling out putting flashes in softboxes; at least I cannot imagine this to work in any reasonable distance to the camera).
• High price for P-TTL HSS flashes.
• Very limited power control over multiple P-TTL flashes.