Looks like another defective new AF-540FGZ flash.

If I understand it right, the Metz needs 1/120 s to fire its maximum output.

So, if you need all the power the Metz can deliver, your camera's shutter speed is limited to 1/120 s (instead of 1/180 s).

This might not be a major problem, but it's at least something you should be aware of.

mutleybird said:

pcarfan said:

mutleybird said:

to beat it in quality.

Click to expand...

Well, not too many users of it yet, and when thay do we'll know for
sure. But, who wants a max. sync. speed of 1/120 for full
power....I'd buy the Penatx 540 again.

Click to expand...

On the K10D it is 1/180 sec. The Metz also does high speed sync.

Click to expand...

--
-- Andreas --

Dreticus said:

If I understand it right, the Metz needs 1/120 s to fire its maximum
output.

So, if you need all the power the Metz can deliver, your camera's
shutter speed is limited to 1/120 s (instead of 1/180 s).

Click to expand...

Dreticus said:

Dreticus said:

Dreticus said:

Well, not too many users of it yet, and when thay do we'll know for
sure. But, who wants a max. sync. speed of 1/120 for full
power....I'd buy the Penatx 540 again.

Click to expand...

Click to expand...

Click to expand...

As per Metz technical response on this subject:

Dear Larry,

attention, the flash duration can be measured according a T10 or another T50 method. The T10 method takes the time from triggering the flash plus 10% and stop the measuring if the light cirve is decreased on 10% again after reaching the maximum. The T50 measures only in 50% leve leading to faster durations.
All of our flash units are measured according T10 method.

Is a AF540 measured according T10 as well?

If a 540 was measured according T50 method, you cannot compare the flash duration with a metz. A 58 AF-1 has a flash duration of 1/125s with a full power flash indeed.

Best Regards

Lutz Goeschel

Technical Support/ Advicer

mutleybird said:

Dreticus said:

If I understand it right, the Metz needs 1/120 s to fire its maximum
output.

So, if you need all the power the Metz can deliver, your camera's
shutter speed is limited to 1/120 s (instead of 1/180 s).

Click to expand...

mutleybird said:

mutleybird said:

mutleybird said:

Well, not too many users of it yet, and when thay do we'll know for
sure. But, who wants a max. sync. speed of 1/120 for full
power....I'd buy the Penatx 540 again.

Click to expand...

Click to expand...

Click to expand...

As per Metz technical response on this subject:

Dear Larry,
attention, the flash duration can be measured according a T10 or
another T50 method. The T10 method takes the time from triggering the
flash plus 10% and stop the measuring if the light cirve is decreased
on 10% again after reaching the maximum. The T50 measures only in 50%
leve leading to faster durations.
All of our flash units are measured according T10 method.

Is a AF540 measured according T10 as well?

If a 540 was measured according T50 method, you cannot compare the
flash duration with a metz. A 58 AF-1 has a flash duration of 1/125s
with a full power flash indeed.

Best Regards

Lutz Goeschel

Technical Support/ Advicer

Click to expand...

This is very ineteresting. Thank you for taking the time to get it sorted out. Now, the question is, how is Penatx measuring the flash duration ?

GaryDeM said:

first. it makes NO DIFFERENCE WHAT THE SHUTTER SPEED IS if the area
is so dark that you need flash to get the shot.

Click to expand...

Outch, don't shout.
I think you haven't understood the [potential] issue with the Metz.

GaryDeM said:

any subject movement
is being stopped by the duration that the flash actually fires.

Click to expand...

When the Metz flash emits full power, its burn time is 1/120.

This is longer than other flashes of similar power. I posted some comparisons a month or two back. But you can find out on your own, should you be interested.

Such a long burn time also means that when using the fastest x-sync shutter speed, part of the flash emission will not be used, because the shutter is already closed when the flash hasn't stopped yet.
Edit: This is of interest concerning burn times:
http://forums.dpreview.com/forums/read.asp?forum=1036&message=25637741

GaryDeM said:

this is a tiny fraction of a second.

Click to expand...

For a specific flash bulb, the burn time depends on the power emitted and can vary quite a lot. For example from 1/20.000 to 1/100 of a second.

Jens

--

'Well, 'Zooming with your feet' is usually a stupid thing as zoom rings are designed for hands.' (Me, 2006)
My Homepage: http://www.JensRoesner.de

pcarfan said:

This is very ineteresting. Thank you for taking the time to get it
sorted out. Now, the question is, how is Penatx measuring the flash
duration ?

Click to expand...

We could ask them

--

'Well, 'Zooming with your feet' is usually a stupid thing as zoom rings are designed for hands.' (Me, 2006)
My Homepage: http://www.JensRoesner.de