580EX - prefers TTL...

[les]

Just had the 580EX delivered. I hoped that the strange behaviour described in

some posts on PN regarding the flash reverting to TTL mode would not manifest

itself - but no such luck...I switched it on before putting it on camera - E-TTL

mode was displayed. OK, switched it off, on the camera, switch on...E-TTL. One

shot (properly exposed - and, all of a sudden - TTL mode displayed. Cycling MODE

button did not help - E-TTL simply disappeared. After couple of switch on/off

cycles, however, it fixed itself, and (so far) the problem disappeared.

When in TTL mode, it appeared firing at full power - the images were blown by a

large number of stops (basically a whiteout).

 

My 550EX - no problem. I guess there is something funny going on with the

flagship Speedlite...

[les]

BTW - I am not impressed with the new locking device on the shoe. I mean - it looks cool, makes a very satisfactory click when I lock it - but the lock is far from being as positive as with 550EX. Maybe Canon engineers should be reminded: if it is not broken - do not fix it...

[rainer_t]

I had this behaviour (flash showing TTL (rather than ETTL) and flash firing full load) with my 430ex. Carefull cleaning of all contacts on the flash and on the camera hotshoe cure it.

[pete_c1]

Same thing happened to me over the weekend with my 430 firing on TTL and most shots

almost completely washed out. Just as Rainer described, a quick cleaning of the contact

points did the trick.

[colinsouthern]

It does this if there's poor communication between the flash and the camera.

 

PS: I know what you mean about the new locking mechanism, but it is something I quickly got used to. One of the issues I had with the conventional mechanism is that I could never remember which way to turn the ring to undo it - and if it was already tight to start with it jot to be quite an exercise.

[jeffreyc]

I also had this issue with my 580 EX. Unfortunately there was a physical problem with the flash and had to be sent back to Canon. The upside was it was under warranty. I would still definitely try cleaning the contacts out and maybe tighten the hot shoe on the camera before sending it in.

[les]

Well, things seem to be OK now (but for how long...?). I do not think that the problem is with the contacts/hot shoe. 550EX never missed a beat - and still doesn't. Considering the number of posts describing the same behaviour in 580EX - I think that it may be some kind of design bug - maybe directly related to the new locking mechanism.

 

OTOH - only during the first couple of shots the 580EX could not decide whether it is E-TTL, or TTL - afterwards all seems to work OK.

[bmeister]

It is LIKELY a simple contact problem. I've experienced the same issue if a flash is not perfectly seated on my 1D, 1DmkII and 1DmkIII with the 550EX and 580EX. This also happened on my Nikon system with the SB-26 and SB-28 flash units. Some contacts connect and the flash just fires full power until I re-seat it and then all is normal. I agree with the "if it isn't broken don't fix it" comment wholeheartedly. This is not to say there may not be a real problem, but make sure that all contacts are clean and the flash is always seated completely.