Using a slave flash with a S2SI

[padylyn]

I have a Canon S2IS camera. I also have a UNOMAT B24CT automatic flash unit. I would like to use this flash unit as a slave flash. I have a small slave unit which successfuly fires the flash. However, I am having problems arriving at the best camera settings.
Could anybody gives me some guidance, please,
Padylyn

[MaxZoom]

I'm not familiar with your flash unit, Google has lots of hits but I can't tell if they are in Mandarin or Cantonese well the pages are mainly from Taiwan anway.:oops:
Unless the flash is specifically a digital slave flash you will probably not find good settings for the S2.
Nearly all digital cameras set off a short pre-flash to check how much energy will be needed for the main flash. This has nothing to do with red-eye reduction. You can buy slave sensors which are 'digital aware' they won't fire until the pre-flash has gone off so when the camera makes the exposure the slave flash (your unit) will be triggered.

See http://photography-on-the.net/forum/archive/index.php/t-140083.html for a discussion of digital flash triggers.