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Originally posted by awaldram Given manual flashes are not capable of switching at the rate required for HSS the cactus RF60 must operate in a similar fashion
Why would the fact that a flash uses manual controls make it incapable to "
switch at the rate required for HSS"?
The Cactus RF60 has a special HSS mode in which pulses similar to P-TLL flashes in HSS mode. The RF60 HSS flash bursts are not just longish 1/1 blasts. The latter approach is better referred to as HyperSync. The RF60 can provide a long HSS burst for power levels lower than 1/1 as well.
Originally posted by awaldram Your solution to his issue cannot work , HSS is not available outside P-ttl
My solution works. Please read my posts in full.
The
part you did not quote was:
There is an unfortunate catch, though because Pentax cameras disable any flash triggering once the shutter speed goes beyond the sync speed. Hence you need an HSS-capable flash on-camera (or connect to the camera via a cable) that you can use as a trigger. You can use either the RF60 directly or the upcoming V6 radio trigger to catch the optical signal and then fire the off-camera RF60.
You are of course correct that given Pentax's limitation, it is not possible to trigger anything beyond a shutter speed of 1/180 unless an HSS-capable P-TTL flash is connected to the camera.
However, my solution includes that aspect.
Originally posted by awaldram from what I understand from your 'review' hss ala cactus style relies on fiddling with pre-trigger delay and hoping the flash will contribute during main flash period.?
Not "fiddling" and not "hoping", but it is correct that one needs to adjust a delay value so that the RF60's HSS burst contributes to the exposure.
Originally posted by awaldram failing true M-sync, FP simulation methods for delivering high shutter speeds are and will remain a klutz of a solution.
It is inconvenient that one has to find the correct delay value first -- thanks to Pentax's limitation -- but once you obtained it, you can write it down and will never have to work it out again (for a given aperture). Note that the RF60's HSS burst is long enough to provide a bit of latitude, i.e., one delay value should work for a range of f-stops (I haven't tested this though).