Hi Amin,
Perhaps I need to add a "high speed flash" section to the e-book
Glad it's started you experimenting!

As I mentioned, I doubt that even full power 1/1 is going to be a problem The duration of a full flash discharge is going to be short enough to freeze most movement. It's only if you find that 1/1 is giving blurred images will you need to reduce the flash power (and adjust aperture/setup/etc to compensate).

Also bear in mind that the recycle time is longer when you discharge fully. So, at 1/1 you'll have to wait 3 or 4 seconds between shots (or more!). As I mentioned, start with 1/2 power since that will give you shorter flash recycle time and more freedom to shoot. If you can't get what you want, try changing the setup.

For example, adding a Fresnel lens attachment to the flash head should "focus" the light on a smaller area. You could even try making a tube out of household aluminium foil to funnel and direct the light onto your subject You may need a more directed light rather than more brute force power.

Have fun!
Matt

Amin,
The "1/2", "1/4" are power outputs used when the flash is in manual ("M") mode. With a fixed setup you are always best using fully manual anyway. Each power stop is one "stop" lower. So, if you had a good exposure with 1/4 at f/8, then 1/2 at f/11 will give you the same exposure, as will 1/8 at f/5.6, and 1/16 at f/4, etc.

However, be aware that 1/1 (full power) takes time to discharge, and that "1/64" will take far less time to discharge than 1/1.

If you are taking shots of a hummingbird then you may need to be using a flash power of much less than full power - to get the really short flash duration. However, if you are taking shots of smoke then I reckon it's not going to matter at all. Try at 1/2 power first and work from there - too bright, reduce the power; too dark, increase the power to 1/1.

The -1, -0.5, 0.00 etc are exposure compensation values - usually when the flash is in P-TTL "intelligent" mode. However, for a fixed setup (like your smoke scenario) you should be on fully manual

Matt

(PS. Sounds like you might need my flash e-book... plug plug )

Well that's a bit pointless
As it's lit by the iPhone/iPod backlight and not by the ambient light I can't see what use that is at all!!

Matt

Amin,
Yes, as long as the ambient light is one or two stops under your "correct" exposure it won't matter - the duration of the flash light will freeze any action.

If you want really fast flash then make sure the flash isn't trying too hard. If the flash discharges completely then it's quite a long flash pulse. If you up the ISO and can get away with around 1/32 power then the flash duration is going to be extremely short (around 20ms perhaps) - that's an equivalent shutter speed of 1/50000 (one fifty-thousandth of a second)

Haven't actually measured the Pentax flash duration...
Matt

The K20D popup flash cannot trigger HS wireless flash
You can only do wireless HS with two flashguns.

Amin - why do you feel you need higher shutter speeds with the flash?

Matt

The best way is to examine the EXIF data on a JPG or PEF file using PhotoME
http://www.photome.de/
You'll find "Shutter Count" listed under the "Manufacturer Notes" section (around half way down)
Matt

Definitely the Pentax smc-FA 50/1.4
It's a bargain even when new at £155 from SRS
Matt

Thanks Joe
My main "work" hat is firmware design and coding - that involves a fair degree of technical writing too ( www.scannex.com ) But it's probably the analytical nature of my work that lets my head retain all this techno stuff on photography.
Photography is my artist outlet to stop the technical rot from setting in too deep! LOL!

Thanks Don That would be a nice thing to happen!

Shim - Now that's made me feel I've shortchanged myself!

Matt

As John says - that's the way it is. I have links (somewhere) of the technical side (I haven't time today to describe it!)

If you're trying to "freeze" action - the flash itself will do this anyway. The burst of light from the gun can be much, much shorter than any focal plane shutter can achieve
Matt

Thanks guys. Trouble is I've read mixed reviews about the WLED displays, and "TrueLife" displays. Some say they are a right pain to calibrate, with poor black points, uneven brightness across the screen, etc.

Having been stung with the Toshiba M200 display, I didn't want to make the same mistake again!

I'm not sure which out of the WLED display, the "TrueLife", or the "regular" LCD from Dell are going to be best for colour accuracy and Photoshop work.

Alas, much as I love the look and spec of the new MacBooks, the cost of replacing all my plugins and other software (some unavailable for Mac) would cost far more than the machine itself

Matt