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Manual Mode Questions 580EX II


I am trying to understand manual mode on my 580EX II flash.  I use this with a 5D Mark III.

1. In M mode, I can set the power rating from 1/1 to 1/128.

2. In Ext M mode, I see the ISO and F-stop and effective flash range.

3. In reading Bryan Peterson's Understanding Flash photography, he describes how on his Nikon SB900 flash, he sets it in manual mode, sets the ISO and aperature and the flash gives him a ideal subject to flash distance. He then changes the power setting and the distance changes.  

4. I don't see anything like that on the Canon 580EX II.  Is there a better description of capability than the manual?




Rising Star

I don't know of any automated way of doing this with the Canon sytem. Nikon just uses the basic guide system but figures it out for you. It is not very hard to figure out though. Just look under guide number in your manual. It will tell you flash output required. Pro wedding photographers relied on this in the film days. 


There are a few easier techniques you can use to nail exposure when your flash is in manual.  



With the 580EX II (also most of the other flashes with and LCD display too) using manual lets you set the power level as you said. If the flash is mounted on the camera and the camera is switched on and the meter is active then there is a set of distance indicators visible on the rear of the flash display to show the distance.


Here's what I did...

  • Put the flash on the camera
  • Switch on the flash and put it in manual (M) and set a power level - 1/8 power in my case
  • Switch on the camera and put it in manual mode (other modes also work the same)
  • Press the shutter button to activate the camera metering, this also sends the aperture and ISO info to the flash
  • The flash display now shows the distance

I just tried with my 600EX-RT and it shows the actual distance in meters on the flash. If you have the flash head bounced then the distance is not shown.


If you put the flash in Ext.M mode then you need to set the ISO and aperture on the flash itself, then the flash will display the distance range. In the Ext.M mode the flash is using a sensor on the front of the flash body to do the metering. Once the flash thinks the subject has received enough light then it quenches it's output - the distance range displayed takes account of the flash head zoom, and user entered aperture and ISO values. Again if you bounce or twist the flash head then the values are not displayed.




EOS specialist trainer, photographer and author
-- Note: my spell checker is set for EN-GB, not EN-US --



Your response was helpful. from everything I have read, it seems that Canon may be a bit behind Nikon when it comes to flash technology. I read in Field Guide for Speedlites that I could use the formula GN / Distance = Aperture but that is way to much manual work in my head. Canon obviously knows the GN number, ISO, and Aperture. It would seem like an easy thing for the flash to display a distance rather than the large effective range.


And then I add another wrinkle in that I am trying to learn how to effectively use Phottix Odin radio triggers. They support putting the flashes in manual mode and setting the power level from 1/1 to 1/128. It seems the only way to figure out what is the proper power setting is trial and error shooting. With all the sophistication built in these days, this seems a little clunky. I want to fully understand manual mode before I rely on ETTL.


I had Syl Arena's Speedliter Handbook and a couple others. I am still searching for a good book that really does a good job of describing manual mode.



For Nikon to do this the flash needs to be on the camera and pointed forward. No camara system is going to be able to provide correct power output for OCF especially using 3rd party triggers.


If you need that type of accuracy I suggest a meter.  The Sekonic L-358 in an excellent, reasonably priced tool for this.   

Hi Kent,


In manual - certainly on the 600EX-RT it does display the distance. On the 580EX II there's just a bar over the distance scale to indicate the distance rather than a range. (page 22 of the 580EX II manual)


If you want to really get a handle on manual then some of the elements in the lighting 101 on is a good start and also Don Giannatti uses a "peice of string method" which actually is a really neat way to think about flash power. Also since manual is your intention then a light meter may be good for you.


The way to figure out the proper lighting is practice, and plenty of it. Over time you get a sense of the amount of power you need for a particular distance with a specific light modifier. Then you kind of extrapolate from there. I find that when using manual I tend to move lights in an arc around my subject, keeping them the same distance from the subject. This ensures that if the light was the right amount it keeps being the right amount.


Two weeks ago I was shooting in a night club, I was using a softbox upfront with an E-TTL controlled flash to light the model. In the background of the club - 50 to 60 feet back - I also had two speedlites in manual mode set for 1/32 power. I had coloured gels on them and grids to control the beams of light. 1/32 power for each was a figure I pulled as a starting point just based on experience.

One thing is that if you fire Speedlites at a camera, best put them in manual mode else the E-TTL II gets a bit confused.


If you are using the Odins then manual is just manual, you set the power of the flash and it gives that power all the time. So if it's too bright - turn it down or move the light back from the subject etc. I'd also suggest you put the camera in manual exposure mode too and use a set ISO not AUTO ISO.

I tend to start in manual at 1/125s f/5.6 ISO 400 and work from there. You may find that working in a dimly lit environment helps you to see the effect of each flash adjustment. 


Syl Arena's book is good, you can also learn plenty from David Hobby aka the Strobist, Joe McNally and Frank Doorhof too. 



EOS specialist trainer, photographer and author
-- Note: my spell checker is set for EN-GB, not EN-US --

Thanks very much for the information.  Greatly appreciated. 

It's too bad Chuck Garners website is down. Got some good infor on the white towel method. You don't need a towel. A white sheet of paper would work. I really on this method even shooting in ETTL. Weddings are easy because most of the time the bride is in white. 


GIve your subject something white if they do not have anything white on. Even a shirt collar when in a suit works. Just be sure there is nothing else in the back/foreground so you misinterpret the histogram.


Take the shot and look at the histogram. The toght side is your whites. This should be almost touching the right wall. Adjust flash power until that is achieved and the rest of yoru exposure falls into place.


Here is another link. My flash guru.

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