Hi speed flash

I want to use a hi speed sync flash on my K5ii for an outdoor shoot. Reading the instruction book. It appears this can only achieved with a Pentax dedicated flash. Is this correct ? I don't want to spend £400 - £500 on a new flash. As I don't use them that much. I own the Sigma 610 ST PTTL flash unit,

Yes is the answer

A used AF360FGZ may be your cheapest option, Metz and Sigma also have some units that will do P-TTL HSS quite a bit cheaper that £400-£500, a Metz AF52-1 is around £200 and a Sigma 610 DG Super is around £160.

Also note that this is HSS will only work with the flash mounted on the camera body or off camera via a P-TTL cable, if you want to do HSS wirelessly you have to have two compatable flash units.

...and if you want a cheap AF360FGZ then there is currently one on Ebay for £70 (inc postage) - that's the cheapest I've seen for a long time.

http://www.ebay.co.uk/itm/111127198619?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1...

I've no connection or interest in the seller - just wanted to let you know it is available

Thanks Brian. I kind of guessed that was the case. We know Pentax are lacking somewhat, in the area of flash control. Not really worth it for one or two shots. I'll have to thinks of other ways to achieve the effect I'm looking for.

Stuart,

This is not a "lack" on Pentax's part

The requirement for a digital 'modern' flashgun is because HSS requires the flashgun to pepper the scene with small bursts of light. And this requirement is the same for EVERY manufacturer
(Unless you have a leaf shutter)

The highest sync speed of 1/180s is the fastest shutter speed where the two shutter curtains are completely open (ie the leading curtain has completed but the trailing curtain has not yet started its travel). Nikons support of 1/250s makes practically no difference whatsoever - it's a mere 1/3stop.

Faster shutter speeds require the trailing curtain to start moving before the leading curtain has completed. At 1/8000s the two curtains will move together, leaving a tiny slit to expose the sensor. To get HSS flash to work means that the gun has to hammer out bursts of light while this slit moves across the frame.

That's why HSS guns (for Pentax, for Nikon, and for Canon) are expensive


On the other hand, if you want to use fill-in flash outdoors then you just have to reduce the shutter speed to 1/180s or less to work with any flash. That may mean closing the aperture down (e.g. to f/16) and reducing ISO, and possibly adding an ND filter to further cut the light into the camera.

Strobist is a good place to look for techniques

HTH!
Matt

Not any more it ain't, couldn't resist at that price

One thing about HSS I don't get is, why is it not possiblle to implement HSS in live view mode as the shutter is fully open all the time?

Is it to do with the mechanics of the sensor electronics scanning the sensors diodes ?

Brian,
The shutter is open while you are viewing LV.
But when you hit the button the shutter unit primes and releases - so it's a normal process without the mirror flip.
Matt

Hi Matt

Thanks for that explanation, I knew it would be simple, I should have check LV first, I very rarely use it.