I tried getting a my Sigma EF - 500 DG Super to work as a remote Slave unit on with my K100D the other day, and it always fired a moment too late.
For the K100 owners out there whom aren't aware our cameras do not have remote flash triggers, although I believe that the K10 does.
This is the best K100D photo I could come up with compared to a similar photo with my Sigma
Well last night I worked at it some more, with some success. Sorry I don't have any fruit at the moment, so I used a couple of other props I have.
I had to manually program the flash, which took a little bit of figuring out. But at least I know that it's possible now.
So I guess that if you want to do something similar with your K100 don't loose hope.
It just takes the right flash and some patience.