Testing a used flash?

[Leopard Lupus]

Hello there!

I am in the market for a used 580ex ll flash to join my first 580ex ll and 430 model.
I was able to find one on CL for $410 with the Canon cable included.
As I have never purchased a used flash, what all am I looking for? How should I be testing such an item?
Thanks in advance!

[briansquibb]

Dont be frightened to buy a 580EX - in the UK they are selling for the same price as a new 430EXII. With flash the bigger the better.

There is very little functionality difference between the 580EX and the 580EX2 - the main practical on is that the 580EXII has better weather sealing on the hotshoe.

I have a 580EXII, 5 580EX and a 430EXII and they all work happily together (also have the STE-2 as the on camera controller). I fire them with PW mini and flex.

Personally I adjust the power output through different distances of the flashfrom the subject - and the same with controlling the ambient. I find this approach is simple, quick to do - and intuitive.

One of the reasons that I use 580s is that they recycle faster than the 430 - and using multiple flash takes less power from each, improving recycle time. When taking pictures of dogs with 3 flash they recycle fast enough for me to take about 5 images at 5fps on the 1Ds3. I always shoot using eTTL.

[Flake]

As you already own a 580EX II you should be pretty familiar with it.

First set the power to max and fire off a couple of pops with the test button (take fresh charged batteries with you for this).  Make sure it charges quickly & silently, obviously if it doesn't fire there's a problem.
Make sure the zoom function works by manually changing it, you should hear the motor & see it move if you look through the lens.
Check the wide angle diffuser and bounce card are both there and that they come out and go back smoothly, the diffuser should cause the zoom to move.  Watch for the spring at the back being in one piece they can & do break.
Attach the flash to the camera in ETTL mode and check it reads the info properly, fire off the odd shot to check it does communicate correctly and then the histogram to make sure it's not wildly out.
Other than that the only other thing is the physical condition which should be obvious, other than the battery compartment for battery leakage.
I think that just about covers everything, no doubt if I missed something someone will point it out, although I think that most flashes will be in pretty good order.

[Penn Jennings]

I don't know where you are located but B&H has the imported 580 EX II for $424.  It might be worth looking into.  At least it will be new and you will have a 30 day return period if nothing else. 

http://www.bhphotovideo.com/c/product/486706-GREY/Canon_1946B002_Speedlite_580EX_II.html

[neuroanatomist]

I am in the market for a used 580ex ll ... I was able to find one on CL for $410 with the Canon cable included.

Do you need the cable?  A brand new 580EX II is $420 on Amazon.com right now, full warranty.  Personally, that's what I'd do.  The off-camera cord is nice, and if you do need it, that makes the deal reasonable - but I'd confirm it's the OC-E3, which is better than the older Canon cord (e.g. same lock lever as on the 580EX II, maintains the weather sealing of the 580EX II when used with a sealed camera body).

[D.Sim]

As you already own a 580EX II you should be pretty familiar with it.

First set the power to max and fire off a couple of pops with the test button (take fresh charged batteries with you for this).  Make sure it charges quickly & silently, obviously if it doesn't fire there's a problem.
Make sure the zoom function works by manually changing it, you should hear the motor & see it move if you look through the lens.

Just... don't accidentally fire the test flash when you're looking through the lens... 

That said though, is there any way to know (or is it even possible) if the power of the flash has decreased? Would, over time, the capacitor lose some of its "capacity", and if it did... Is there any way to know?