Canon wireless and ratio setting: 580EX master, 420EX slave (and an umbrealla ...)

[taner]

Hi there

 

I just finished two intense days of shooting with this set up (got

paid too!):

 

Master 580EX off camera with off-shoe cord mostly direct use as fill,

Slave 420EX on a stand with Manfrotto umbrealla adapter and umbrella

as key, XT/350D.

 

Being an absolute beginner with anything other than hotshoe flash

usage, I obviously cannot report/speak with any authority here, but I

think that the A:B ratio settings were rather inconsistent - and

certainly less than 'convenient' than what Canon's promo literature

would have you believe. The 580EX manual provide lots of

three-580EX-and-one-ST-E2 diagrams...

 

The rental place people attributed this to the shortcomings of the

420EX vis-a-vis the 580EX. Another photographer who happenned to

listen to all this thought that the umbrealla set-up was responsible

for the inconsistency, and argued that the Canon wireless E-TTL system

was not even precise enough for ceiling-bounce 'complications'...

 

I would appreciate your comments/suggestions. Thank You.

[uhshopeonuhrope]

i used a 550ex as master to two 420's for about 15 senior portrait clients and two weddings. i was also very dissappointed with the set up. on lots of occasions the lights didn't seem powerful enough, and on most others they just weren't taht easy to set up. using ratios or increasing stops or whatnot. fortunatly i just had the set stolen so now i'm researching a new portable lighting scenario for uner 600. any ideas??

[oofoto]

Hi, any chance of posting some of the shots? I'm interested in seeing what this setup is capable of. Thankyou.

[jim_leonard]

I find that canon wireless system works fairly consistantly if it's used consistantly and assuming that none of the groups are underpowered.

 

First off, I would guess that your 420ex was running at full power most of the time, you fired your weaker flash into an umbrella and unless the umbrella is fairly close and/or you were using ISO 400 or higher you probably needed more light.

 

Secondly (and this is just an extention of the same problem that most people with flash consistancy problems with canon flashes have), all of the flash metering is basically spot metered off of the current autofocus sensor. This is especially touchy with a multiflash system because if the metered surface reflects light from group A into the camera light meter better than light from group B (due the angle of the surface for instance) then group B will get an excessive power level (and group A a similarly reduced power level) than what you would expect if the spot under the AF sensor isn't representative. This situation can be exagerated further if the area under AF spot can't see group B's flash at all (then group B will fire at full power regardless of what it'll do to the rest of the exposure).

[taner]

Shooting Mode Program AE

Tv( Shutter Speed ) 1/60

Av( Aperture Value ) 4.0

Metering Mode Evaluative Metering

Exposure Compensation 0

ISO Speed 100

Lens 50.0mm

Image Size 3456x2304

Image Quality Fine

Flash On

Flash Type External E-TTL

Flash Exposure Compensation 0

Red-eye Reduction Off

 

Thanks for your responses. I am afraid I am not able to post any images from the 'paid job' yet - but there are some shots I took at home playing around with the set up, partially, and fully.

 

I can say this right away; as long as the shooting distance is reasonable (like in a small to mid size room), an umbrealla - 580EX - off-shoe cord (dedicated Canon cable) combo gives some good results. Not necessarily without playing around with FEC though. Add a reflector to the equation (which I did not), you might be able to get great results (in comparison to either direct flash or bounce flash) for such a simple set up.<div></div>

[taner]

the same shot with a bit of levels tweaking.

[taner]

here it is<div></div>

[taner]

so probably 1/2 or 1 stop FEC would have been just right for my taste.

[taner]

Jim, thanks for your input; I am afraid your third paragraph is a bit difficult for me without sample shots or a diagram... As I mentioned earlier, I am new to this.

 

this shot is with the same settings as the one above, plus +2 FEC (obviously too much...)<div></div>

[taner]

<div></div>

[taner]

again same settings, but +1 FEC this time.

[taner]

here it is - no post processing other than USM<div></div>

[taner]

and with a bit of levels tweaking<div></div>

[taner]

two final notes my stupid EF 50/1.8 lens front-focuses consistently, and my monitor is not calibrated. Cheers.

[taner]

again all of the above: umbrella, 580EX, off shoe cord - NO 420EX here.

[peterlee]

I just bought a 580EX this past weekend and have been playing with it. So far I've only used the automatic setting and have found the results to be varied. Most of my ceiling bounce shots have been under exposed.

 

My shot with bright back lighting caused the subject to be very under exposed. I was hoping it would do a nice fill.

 

I'm not ready to blame the flash unit just yet since my experience level is really low with flashes but I have been considering the same setup with the 420ex as a slave so I'd be interested in hearing from anyone else who has experience with this setup.

 

Any success stories or tips?

[nello]

I think the Canon flash system is great, but like everything in life good results take practice! In this case, the Strength of the system is also its Weakness: TTL metering (E-TTL etc.)

 

Readings via TTL will vary from shot to shot (as per slight changes in camera position, model adjustment, outside lightsources, change in the way shadows fall, etc.) Accordingly, flash output will vary as the camera sees fit to adjust. Rather, a system based on a changing variable will give you variable results.

 

You could set the flash to manual, on the other hand. You'd loose the convenience of multi-flash TTL but you'd gain consistency in flash output. (Yet still have the portability and easy setup vs.

"heavier duty equipment").

[taner]

Thank you all for your responses, cheers.