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warhammer
09-12-2010, 1:24pm
i was taking a few shots of this lizard the other night using a 580ex2 flash in one hand and my camera in the other, half the shots turned out ok and the other half had half of black strip on them.
does any one know what could be happening here?
i checked to make sure it was not a object in front of the flash and camera, the only thing i can think is it is one of my shutters.
any help would be good..
cheers warhammer.......

kiwi
09-12-2010, 1:25pm
your shutter speed was higher than your maximum flash sync speed

BLWNHR
09-12-2010, 2:22pm
your shutter speed was higher than your maximum flash sync speed

This.

EXIF says SS was 1/500.

kiwi
09-12-2010, 2:27pm
...and the 7d's maximum flash sync speed is 1/250s, so effectively the shutter is frozen by the flash as it works

Im not familar whether Canon camera match the brilliance of Nikon allowing you to have a high speed flash sync

warhammer
09-12-2010, 7:08pm
thanx for the info kiwi and blwnhr.
so i guess that means that no matter what the situation i cant go over 1/250s yer.....?

kiwi
09-12-2010, 7:27pm
Not necessarily, the 7d might have a feature called high speed sync, read your manual or call a friend here

Cadnium
09-12-2010, 10:16pm
warhammer,

What was said above is almost definately the case. From your exif, it says there was no flash fire. I assume you are getting off-camera using a third party product? If you want to high speed sync, i am pretty sure you will need a proper sync cord (don't quote me on that though).

You will need to set high speed sync in the 580exII. Check out page 17 of the manual.

warhammer
10-12-2010, 12:06am
cheers all, i was using pocket wizards plus 2. and it says 1/250 was max for focal plane shutters and 1/500 for leaf shutters, im guessing my 7D is focal plane shutter.
its all a learning curve, maybe i should read manuals in more detail more often though....

how do you read exif, were is it on here..?

MarkChap
10-12-2010, 12:11am
Warhammer,
Using pocket wizards, or any other non TTL, flash trigger on the 7D will only allow a maximum of 1/250 sync speed, if you use the built in speedlite controller on the 7D, you can still only achieve 1/250, but if you use a 580EXII on camera as a master and another Canon flash off camera as a remote, you can then achieve high speed sync, up to the max shutter speed of 1/8000

And yes your 7D has a focal plane shutter

Boo53
10-12-2010, 12:35am
how do you read exif, were is it on here..?

Warhammer

you can get an add-on for firefox to read exif https://addons.mozilla.org/en-US/firefox/addon/3905/

warhammer
10-12-2010, 12:57am
cheers markchap and boo53..
im getting a new mac next week so i will put that on the list of must have stuff installed.

jeffde
11-12-2010, 5:57pm
Hi

The high sync speed is on the flash - press the flash / H button until fl;ash symbol / H appears next to ETTL
The set your sperture - Then you shutter speed can be more than 1/250 th sec.
Google - 580ex high speed sync - for more info...

warhammer
12-12-2010, 8:41pm
cheers jeffde...