Originally Posted by Chuck Lee
Chuck, Canon has a sneaky way of embedding guide number into its product names. The 430 has a guide number of 43 (meters, at ISO 100 and f/1). The 580 has a guide number of 58 (meters, at ISO 100 and f/1). So, I guess the model number is the guide number in decimeters?(And the 580 adds full rotation head, external battery input, PC input, auto-thyristor flash, and the catchlight panel.)
We're a Canon/Profoto family: five cameras, sixteen lenses, fifteen Profoto lights, too many modifiers.
Thanks peety, That's why I always use the phrase "I think the....."
So, inorder to balance the two Mark will need to do a little calculating. So the 430 has 43/58 the power of the 580? Is that correct?
Rounded out with about a 1/3stop margin of error and I'd say 2/3 the power. Correct? So, to get a 2:1 ratioof the 430 to the 580 (that would be the 430 used as the key) Mark would need to set the 430 at full and the 580 to 1/4 power. Oh, but wait, We haven't accounted for the subject distance. Dang, this is going to get confusing.
That's what makes using Vivitars so much fun!! They're identical.
Mark, practice at home the best you can. Good Luck and God Bless you brother.....
peety?........what say you?
I think/suspect he's going to work E-TTL since he's constantly mobile. In that case, the camera meter will see the intensity of the A group (i.e. the 580 on-camera) and the intensity of the B group (i.e. the 430 off-camera), figure out how much variation is needed to achieve a 1:4 ratio, and command that in time for the actual exposure. A 1:4 ratio means the 430 will be asked to provide 4x as much (metered) light, but it might be closer to the subjects so it's all a guess.
Think of it this way: you'll wish the 430 would beep when ready again.If it's ready (the focus assist lamp will blink when in slave mode and ready) in <=2 seconds, you're probably at or below half-power, and that's a good thing.
We're a Canon/Profoto family: five cameras, sixteen lenses, fifteen Profoto lights, too many modifiers.
I laughed for a good 15 seconds straight after reading that. :-)
I laughed for a good 15 seconds straight after reading that. :-)
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Yeah, but not nearly as much as a post on POTN a few years ago.
Guy was at work, his wife as at home, and a family friend had stopped by the house. They were talking cameras, and wife wanted to show friend her hubby's camera. Wife calls hubby at work, asks where the camera bag is, he tells her.
After work, hubby gets home, and wife asks him "why do you have three cameras?!!!" Hubby thinks to himself, "sweet, she ONLY found three of the cameras!"
All those in favor, raise your right hand and say "that's me!"
We're a Canon/Profoto family: five cameras, sixteen lenses, fifteen Profoto lights, too many modifiers.
I think/suspect he's going to work E-TTL since he's constantly mobile. In that case, the camera meter will see the intensity of the A group (i.e. the 580 on-camera) and the intensity of the B group (i.e. the 430 off-camera), figure out how much variation is needed to achieve a 1:4 ratio, and command that in time for the actual exposure. A 1:4 ratio means the 430 will be asked to provide 4x as much (metered) light, but it might be closer to the subjects so it's all a guess.
Think of it this way: you'll wish the 430 would beep when ready again.
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You're right. I won't be taking too many "formal/posed" shots so I'll be moving around a lot which is why I plan on using E-TTL. Ihoping that when using E-TTL it did the math for you but does the 580 know that it's triggering a 430 as opposed to a 420 or even another 580?
The trigger doesn't know and doesn't care. You can easily have a bank of 12 flashes (or up to three, as Canon wireless supports three groups A/B/C). During the E-TTL process, the group fires a test flash at a low power (maybe 1/32, I don't know if this is public knowledge at all) and the camera meters the result. Every flash in the group fires at 1/32 for the test flash. The camera figures out what power level is needed, and commands the group to fire at that power. If the power level is 1/8th, then every flash in that group will fire at 1/8th for the picture. If you had a 580 and a 430 in that group, they'd each fire at 1/8th, so there would be less light coming from the 430 than the 580, but the camera would be happy.
This shot was two 580s above (side-by-side, into a shoot-through umbrella, gelled purpley with Rosco 59 or 358 for a moonlit look) and a third 580 off-camera-right, just above camera height, snooted with a full CTO gel for sunset look. The moonlight 580s were in group A, and the sunset 580 was group B. I couldn't get enough light for the moonlight, so I punted to a second flash.
We're a Canon/Profoto family: five cameras, sixteen lenses, fifteen Profoto lights, too many modifiers.
<p style="CLEAR: both"]Doy! I forgot about the test flash [:$]
<p style="CLEAR: both"]Cool pic by the way. I love the tone. It feels like wintery light.
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