High Speed Flash

Can someone please give me some guidance on High Speed Flash. I have a K-5 plus a Metz 50 AF-1 flash which has a High Speed Flash mode.

Last weekend I took pictures at a mountain bike race. I used flash for the majority of pictures. I set the camera to its flash speed of 1/180sec. On viewing the pictures many of them showed some visable motion blur, obviously caused by the slowish shutter speed. Could I have used High Speed Flash, and if so what are the recommended camera settings? Thanks.

High speed flash could possibly have been used, depending upon the distance between the subject and yourself.

High speed sync flash works by sending a series of flash in close sequence with a lower power, thus greatly reducing the range of the flash.

Thanks for that. Is there a limit as to what shutter speed HSS will cope with, 1/250, 1/500, 1/1000 etc? Obviously to compensate for the reduced flash range I'd need a wider aperture and/or higher ISO setting.

Below are a few tips and possible solutions:

In order to use the Metz flash in HSS mode it will need to be in PTTL HSS mode. In other words the Metz flash will need to be in contact with the hot shoe of you camera. you will then be able to use any shutter speed and fire the flash.

Flash freezes the action, but your flash's ability to do this effectively will be determined by the power of your flash and its distance to subject.

High speed Sync will enable you to use a faster shutter speed, but you will lose a lot of power and the flash works in a very different way.

What lens are you using and a what focal length and f/ stop?

OK some solutions you could try:

Have tried putting your flash in manual mode and altering flash power and the flash's zoom focal length?
You could try panning with flash and see what you get?
From the action work I have done, I have found bouncing the flash with light modifiers can help with spreading light.
You could try using a reflector to throw some light on the subject?

Action photography is not easy, and mixing in flash and doing it effectively will require practice and a good understanding of the sport and action you are trying to capture. Knowing where to place lights in relation to where the action will be is key. Moreover you may find you can't use flash or put the lights were they need to be.

Try one of these, for metz , lens of 300mm + though
http://www.naturescapes.net/store/fx-6-better-beamer-flash-extender.html
http://www.naturescapes.net/store/better-beamer-flash-extenders/

No, with a Pentax flash you can select any shutter speed that your camera allows. I have no experience of your particular flash though so you'll need to check the instruction manual to see if it has any shutter speed limitations.

If all else fails, just try it. If it doesn't work you'll probably notice some banding where parts of the exposure are illuminated by flash and other parts not.

Thanks everyone.

this might be of help
http://www.rpphoto.com/howto/view.asp?articleID=1026

If you are not trying to create the effect/illusion of speed by using second/trailing curtain synch., you might as well leave your flash set to HSS. When your shutter speed becomes too fast for standard mode, HSS mode kicks in on the flash, indicated by an H symbol in the display. Below the cameras maximum synch speed the flash will revert to standard non-HSS mode.