580EX II & 30D behaviour
Pindy
Registered Users Posts: 1,089 Major grins
Having a couple RTFM moments that I cannot figure out. Maybe somebody can help?
1) When I set CF in the 30D to "2nd-curtain sync" with the 580 attached, the flash ALWAYS fires on the first curtain. I Have to set the 2nd-curtain mode on the flash to behave properly. Why is this?
2) With the 580 off the camera, the CF applies to the built-in flash and functions as expected—rear-curtain works fine. Again, why would this apply only to the internal? Furthermore, what if you were using big strobes? Maybe the sync port is governed by this CF and maybe this only DOESN'T govern hot shoe flashes. But if you use a PocketWizard, does that use the hot shoe for sync or the PC port?
3) In Av mode, and the flash in ETTL mode, you can drag the shutter no problem. It's set for "auto" in the "Av flash sync speed" CF.
Why, then, when I switch the flash to M mode, does Av mode snap the SS to 1/250s? Doesn't anybody want to drag the shutter using manual flash?
4) Bonus problem: on page 26 on the 580EX II manual, it says when 2nd-curtain sync mode is active, you cannot set wireless flash mode. Is that because the slaves will not fire quick enough as the curtain comes down?
1) When I set CF in the 30D to "2nd-curtain sync" with the 580 attached, the flash ALWAYS fires on the first curtain. I Have to set the 2nd-curtain mode on the flash to behave properly. Why is this?
2) With the 580 off the camera, the CF applies to the built-in flash and functions as expected—rear-curtain works fine. Again, why would this apply only to the internal? Furthermore, what if you were using big strobes? Maybe the sync port is governed by this CF and maybe this only DOESN'T govern hot shoe flashes. But if you use a PocketWizard, does that use the hot shoe for sync or the PC port?
3) In Av mode, and the flash in ETTL mode, you can drag the shutter no problem. It's set for "auto" in the "Av flash sync speed" CF.
Why, then, when I switch the flash to M mode, does Av mode snap the SS to 1/250s? Doesn't anybody want to drag the shutter using manual flash?
4) Bonus problem: on page 26 on the 580EX II manual, it says when 2nd-curtain sync mode is active, you cannot set wireless flash mode. Is that because the slaves will not fire quick enough as the curtain comes down?
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Comments
The 30D is setup so that when in AV mode and using an attached speedlight (580EX for example), it wants the flash to be "fill" flash. That's why you can drag the shutter in AV mode.
When you switch the flash to manual mode, the 30D thinks you want your flash to be the "main" light source, hence the top X-sync speed of 1/250. This is no surprise as you have the option in CF to force 1/250 in AV mode.
If your in AV mode, and your not in ETTL on the flash, how would the camera/flash know how long to burn the flash tube for a proper exposure?
It wouldn't...
Camera manufactures have to make choices, and that's what was chosen here. You have other choices to accomplish your goal. -- IE: camera manual mode --
Is there some particular reason that your stuck on trying to make this happen in AV mode, even though it goes against it's programing?
Sounds like you want/need total control to do what you want.
That's a good job for camera and/or flash manual mode
Hope that helps...
Does that mean that:
A) You would never use Av in a studio lighting capacity?
I think I answered my own question. Any kind of automatic mode would give you inconsistent results. OK, OK I get it now. Manual ahoy!