Does Canon 30D Pre-fire Speedlight?

Hi, all. I'm an old-time A2 user and I always hated the pre-fire of
the Speedlight flash when tilted upwards (bounce-flash) in order for
the metering to work correctly. Does this still happen with the 30D
and new 580EX2 flashes? A pre-flash is not only annoying but it also
triggers slave units waiting for the real flash!
Thanks for the info!

On 14 May, 22:55, geek wrote:
Hi, all. I'm an old-time A2 user and I always hated the pre-fire of
the Speedlight flash when tilted upwards (bounce-flash) in order for
the metering to work correctly. Does this still happen with the 30D
and new 580EX2 flashes? A pre-flash is not only annoying but it also
triggers slave units waiting for the real flash!
Thanks for the info!

I had a look in the manual of my 580EX (not 2). I cannot find an
option to disable the preflash. There is a custom option to disable
the modelling flash but I think that this is something else.

A while ago, Gisle Hannemyr responded to one of my Canon flash
questions with this useful link. It has a section on the subject but
I have not read it carefully since it is not relevant to me (I only
own one flash).

http://hannemyr.com/photo/flash.html

--
Seán O'Leathlóbhair

geek wrote:
Hi, all. I'm an old-time A2 user and I always hated the pre-fire of
the Speedlight flash when tilted upwards (bounce-flash) in order for
the metering to work correctly. Does this still happen with the 30D
and new 580EX2 flashes? A pre-flash is not only annoying but it also
triggers slave units waiting for the real flash!
Thanks for the info!

Yes. Canon uses E-TTL or E-TTL II systems for their digital slrs, in
conjunction with all EX-type flash speedlites. But the pre-flash is
very quick, most people don't see the double flash.

I believe there are slave units that ignore the pre-flash, and Canon of
course has their radiocontrolled system for firing EX units as slaves.

Colin D.

--
Posted via a free Usenet account from http://www.teranews.com

That stinks... I have a bunch of regular slave studio lights... I used
to use my old 430EZ Speedlight stopped down really low to add a
sparkle to the eye and trigger the slaves. Now, this new Speedlight
will trigger the slaves too early!

geek wrote:
That stinks... I have a bunch of regular slave studio lights... I used
to use my old 430EZ Speedlight stopped down really low to add a
sparkle to the eye and trigger the slaves. Now, this new Speedlight
will trigger the slaves too early!

yep, 'fraid so. The reason is that film cameras used the reflected
light from the film surface to decide the exposure, and to quench the
flash at the appropriate time. Digital cameras do not give the same
reflection from the anti-aliasing filter in front of the sensor, so that
method doesn't work. Instead, the regular meter sensor is used, which
means the mirror has to be down when the exposure measurement is made,
hence the double flash. First flash, mirror down, measurement made,
mirror up, exposure with second flash made.

The price of progress sometimes means obsoleting earlier systems.
Commiserations.

Colin D.

--
Posted via a free Usenet account from http://www.teranews.com

Seán O'Leathlóbhair writes:
On 14 May, 22:55, geek wrote:

Hi, all. I'm an old-time A2 user and I always hated the pre-fire of
the Speedlight flash when tilted upwards (bounce-flash) in order for
the metering to work correctly. Does this still happen with the 30D
and new 580EX2 flashes? A pre-flash is not only annoying but it also
triggers slave units waiting for the real flash!
Thanks for the info!

I had a look in the manual of my 580EX (not 2). I cannot find an
option to disable the preflash. There is a custom option to disable
the modelling flash but I think that this is something else.

You can shut down the 580EX (and 550EX and 430EX) pre-flash by setting
it to Manual. You will of course also lose its main feature, the
E-TTL (II) exposure control, if you do this, since it depends on the
pre-flash.

You can't shut down the pre-flash on the 30D (or any other Canon
DSLR), nor the 420EX.

A while ago, Gisle Hannemyr responded to one of my Canon flash
questions with this useful link. It has a section on the subject but
I have not read it carefully since it is not relevant to me (I only
own one flash).

http://hannemyr.com/photo/flash.html

--
- gisle hannemyr [ gisle{at}hannemyr.no - http://hannemyr.com/photo/ ]
------------------------------------------------------------------------
Sigma SD10, Kodak DCS460, Canon Powershot G5, Olympus 2020Z
------------------------------------------------------------------------

On 21 May, 14:43, Gisle Hannemyr wrote:
Seán O'Leathlóbhair writes:
On 14 May, 22:55, geek wrote:
Hi, all. I'm an old-time A2 user and I always hated the pre-fire of
the Speedlight flash when tilted upwards (bounce-flash) in order for
the metering to work correctly. Does this still happen with the 30D
and new 580EX2 flashes? A pre-flash is not only annoying but it also
triggers slave units waiting for the real flash!
Thanks for the info!
I had a look in the manual of my 580EX (not 2). I cannot find an
option to disable the preflash. There is a custom option to disable
the modelling flash but I think that this is something else.

You can shut down the 580EX (and 550EX and 430EX) pre-flash by setting
it to Manual. You will of course also lose its main feature, the
E-TTL (II) exposure control, if you do this, since it depends on the
pre-flash.

Of course, I had missed that possibility because after paying so much
for the flash, I didn't want to give up E-TTL. However, I expect that
there are circumstances in which it is necessary or useful to do so.

You can't shut down the pre-flash on the 30D (or any other Canon
DSLR), nor the 420EX.

A while ago, Gisle Hannemyr responded to one of my Canon flash
questions with this useful link. It has a section on the subject but
I have not read it carefully since it is not relevant to me (I only
own one flash).

http://hannemyr.com/photo/flash.html

--
- gisle hannemyr [ gisle{at}hannemyr.no -http://hannemyr.com/photo/]
------------------------------------------------------------------------
Sigma SD10, Kodak DCS460, Canon Powershot G5, Olympus 2020Z
------------------------------------------------------------------------

--
Seán O'Leathlóbhair