A lot of unsharpnes in shooting receptions - help requested

[jsanders]

Hello everone,

Yesterday I took pictures with my Nikon D80 of an opening of a new company. It was a reception inside a company. I prepared very well. I wrote down a list of things for my camera. About the settings. Like:

-Try to shoot on F8 and A preset
-ISO 400 since it's indoors
-Raw
-Balanced lighting TTL
-I also used a flash bounce card which worked quite ok.

Then when I went home, I saw a lot of unsharpness in my pictures. It were pictures with people moving around, people eating. And then I looked at my shutter time: and then I figured they where all on about 1/15 - 1/20. My question is what the minimum shutterspeed should be for such an occaision

[RexK_Cozumel]

depends on the effect you want to achieve.

Since you are using flash you can just turn on rear curtain sync flash and use the flash to freeze the action. But you will get motion blur from the slow shutterspeed and then a sharp image from the flash. See some of Joe McNally's work he likes to do that kind of stuff during events.

If you do not want any motion blur then you can use a faster shutter speed and kill the ambient light and just use the flash to expose the subject. Try setting a shutter speed of 1/80 or faster. This will stop most casual subject motion. It will not freeze a kid running around or cars moving or people walking through the frame but if someone is just swaying or casualling mingling it should be fast enough to stop the motion.

[digirebelva]

What where you shooting on AV, TV, or M
I founf out at least on Rebel that in order to use an external flash I had to use M and set shutter speed myself otherwise the camera would consistently set a slower shutter speed.

[jdepould]

If you shoot A with slow/rear sync on, it'll do that. Anything over 1/60s should kill the kind of blur you encountered.

[OsmosisStudios]

I always shoot full on manual when I use a flash. Saves me trouble.