[SuperAkuma]

I bought the Sigma 530DG super at the same time that I bought my K20D December of last year. The sucky thing is that I lost the manual and I never really learned how to use ANY flash. I've only used the flash a few time and I left it on auto. I don't know if I am using it right but I am able to get the job done. On auto it does a pretty good job after a few test shots.

When using the flash, I leave the Sigma on auto and put the camera on Av mode. I noticed that the shutter speed is 1/60 to 1/180 depending on the focal length the lens is. Why does it not stay at 1/180 sec? Isn't that supposed to be better if I want to stop the action? Is there anything else on the camera that I should set?

I want to take advantage of the more advance feature like being able to use it wirelessly. I am able to get my K20D to trigger the Sigma but for some reason I did not see any effect. The Sigma DOES fire but the picture looks the same as if it didn't fire.

That is all the question that I have right now.
I tried to download the manual from sigma site but they don't have the Pentax version on there. Any links to anything that tells you how to use the flash would be great.

Also can someone tell me what this is or have they used this before?
http://sacramento.craigslist.org/pho/1170616338.html

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Last edited by SuperAkuma; 05-20-2009 at 09:09 PM.

[eyou]

When using the flash, I leave the Sigma on auto and put the camera on Av mode. I noticed that the shutter speed is 1/60 to 1/180 depending on the focal length the lens is. Why does it not stay at 1/180 sec? Isn't that supposed to be better if I want to stop the action? Is there anything else on the camera that I should set?

the shutter speed does not effect stopping the motion or the flash exposure. its crazy i know. it only effects the amount of ambient light in the picture.

the flash pulse duration is so much faster than the shutter that it will have the exact same amount of light regardless of shutterspeed. to change flash exposure you change aperture/iso.

since the duration is so short it freezes the action as long as the ambient light is not overpowering the flash. check out the high speed photography group on flickr, it's pretty awesome. theres no ambient light contributed to those photos just the flash, which is why they can freeze the action at such high speeds.

if you have a shutter speed long enough that the ambient light comes to play you will see some 'blur' around the ambient light edges and the flash exposed part will start to get blurry once the ambient light overpowers the flash.

its really weird i just started experimenting with it a few weeks ago and was totally confused when changing the shutter speed did not effect the flash exposure. hope that helps

[flyer]

the shutter speed does not effect stopping the motion or the flash exposure. its crazy i know. it only effects the amount of ambient light in the picture.

That's true, but only up to a point. If the ambient light level is high enough, you can end up with a "ghost" surrounding your subject. You can always put your camera mode dial to "X" to lock it a 1/180 sec. or use your camera on Tv. On Tv, the camera wont allow you to select a shutter speed higher than 1/180 with the flash on.

You can find a copy of the manual there:http://www.sigmaphoto.com/flashes/manuals/F10EO.pdf

The 500 and 530 flashes are the same except for a slightly mor powerful head design on the 530.