if you had to choose only one

I am new into wedding photography and i am trying to widden my tools but of course i am on short budget (old new)
so i am now stuck between a choice
i can get a Flash 580EX speedlite
or
a prime lens like the EF 50mm f/1.4 or EF 85 f/1.8
so which is most important???
can you help

That depends. your sig says you already have a 580. So does this mean you are getting a second 580EX?

The flash. You also need a second body and backup equipment.

Another camera.

Assuming you've arranged or have a plan for a backup body, my completely unqualified opinion is that you should get a used 50 or 85 AND either a used 580 or I would recommend the Sigma 530 Super as well. I'm quite happy with it, but I've never used a Canon flash.

EDIT: I guess that actually depends on what your shotting style is. There is really no reason to have a second flash if you can't see yourself setting up off-camera lighting (since you can only fit one on the camera).

liza wrote in post #4162353
The flash. You also need a second body and backup equipment.

Dear Liza, thank yuo for your reply...

getting the flash is a good step, but does that mean that the kit lens i have now can help me for a while???? or the lens is a must too.

amonline wrote in post #4162374
Another camera.

HeyAmonline.... i can't afford anything but the 350D now and i think i need to get more lens and equiepment before i change the body LOL...
but thank you for the help

amironsi wrote in post #4162553
HeyAmonline.... i can't afford anything but the 350D now and i think i need to get more lens and equiepment before i change the body LOL...
but thank you for the help

Amonline wasn't saying get a different camera, just get another so that you have 2, in case one dies during your shoot!!!

sm1rf wrote in post #4162630
Amonline wasn't saying get a different camera, just get another so that you have 2, in case one dies during your shoot!!!

Amonline, my apologizies.... can anyone give to me as a gift?

if i were you, i'll just get a 24/28 - 70/75ish lens since you already have a lens for your wide end. but if you really want to get any from the choices you gave i'll just get the 85 1.8 since again you have the kit lens which covers 18 - 55. getting a 50 1.4 just overlaps your existing lens and for me is not adviseable since your on the process of building your lens line up. hope these helps ...

EDIT:

i think getting a flash should be your last concern as of now since you already have one. your money will be better more spent in getting a lens

amironsi wrote in post #4162546
Dear Liza, thank yuo for your reply...

getting the flash is a good step, but does that mean that the kit lens i have now can help me for a while???? or the lens is a must too.

The kit lens really isn't a good one for weddings, which tend to occur in dimly lit settings. I'd recommend a prime or an f/2.8 zoom.

Like many shooters just getting started or in the first couple years of shooting weddings (myself included!) there are alot of areas that you want to upgrade your gear. I do find everyone says the same thing : you need XXX lens, and another flash, and another body, and this and that oh and get 2 of everything for backup. I do agree with that advice but for some it really needs to be done a piece or two at a time.

It looks like you already have a 580EX flash, unless you are setting up off camera lighting I would skip the 2nd flash at this time (definitely get it down the road though!). I would look at replacing your 18-55 kit lens first - get something decent that you will use for the bulk of your wedding shooting - I opted for a Tamron 17-50 F/2.8 over the Canon 17-55 F/2.8 IS for financial constraints. I would then look at getting a fast prime such as the 50 1.4 or 85 1.8 for when the lights get really dim. Lastly, beg, borrow, buy, or steal a 2nd camera body for your weddings.

Like everyone says.... two cameras... at minimum!

Reasons: You don't have to switch lenses all the time.. I usually have two, sometimes three cameras on the go all with something different... that way you're always ready for the shot. AND if you have a camera that decides to not behave.. that's fine, you have another.

If you're shooting weddings, and you're serious, just buy the gear. Any wedding photog can have the gear paid for in no time. Shooting with sub-par lenses will make your job 100 times harder.

get a Sigma 24-70mm/2.8 and get rid of that kit lens. I bought mine used for about $350