New flash or prime?

[4g63photo]

Hello. I have been doing family events for the past year. I have been pretty successful so far. I was thinking of buying either another flash like the Canon 430II or the Sigma 30mm. The flash would be good incase the first one dies. The lens would be great for those creative insane DOF shots. The problem with the prime is that I would hate the hassle of re-calibration. My current gear includes.....
Canon 40D
1D mark 2n
24-105 f4 IS
17-55 2.8 IS
70-200 2.8 non IS
85mm 1.8
300mm 2.8
Canon 580 Ver II
thank you sooo much for reading. Any suggestions would be greatly appreciated.
Rereading my thread I suppose I answered my own question.... a second flash in case the first one dies.

[sapearl]

Hi Fernando, and Happy New Year. If you are doing a lot of heavy duty family and group events that require flash use I would certainly buy another strobe as your backup. This would be essential insurance. You've got a nice lens lineup - I shoot weddings and actually have fewer lenses than you.

I don't understand your comment about re-calibration. What does that involve and why the necessity?

[4g63photo]

Hello. Happy new year to you too.
I was reading reviews of the Sigma lens. It seems to be a great lens but it from what I read a majority of people have to send their lens to Sigma to get the focus re-calibrated because its not spot on.
You are right in regards to the flash. I will pick one up in the next few days. Im looking into the 430.

[tim]

Flash. I love my Sigma 30 F1.4, but i'd get the flash first. The first 30 I tried wasn't accurate to focus, the 2nd was great.