Canon 5D flash sync question.

Since this subject is related to flash sync, I thought I'd ask it here.
I have been taking some product shots for a new website I will be
launching in a few weeks (it's actually up and running, but not much is
there). While taking my product shots, I noticed some shading of what
should have been an even background (different colored backdrops). I
decided to lower the shutter speed, because it looked like a sync problem.

Here are two photos that show the effect:

http://www.dyesscreek.com/hidden_pages/sync.html

On the left is a 1/200 exposure. On the right, 1/160. After some brief
research, I found that the 5D manual states that the sync for studio
strobes may be as low as 1/125 so I was relieved that it didn't
indicated any problem. My question is why the difference between the
studio strobes and a hotshoe flash? The obvious answer would seem to be
the flash duration, but on second thought, that can't be it, can it? I
am using Alien Bees B800s which supposedly have a flash duration that is
1/3200 or so and even at half that, I didn't think that slow enough to
cause a sync problem. At full power many hot shoe flashes have a flash
duration in excess of 1/1000. What gives?

Eric Miller
www.dyesscreek.com

"Eric Miller" wrote in message
.. .
Since this subject is related to flash sync, I thought I'd ask it here. I
have been taking some product shots for a new website I will be launching
in a few weeks (it's actually up and running, but not much is there).
While taking my product shots, I noticed some shading of what should have
been an even background (different colored backdrops). I decided to lower
the shutter speed, because it looked like a sync problem.

Here are two photos that show the effect:

http://www.dyesscreek.com/hidden_pages/sync.html

On the left is a 1/200 exposure. On the right, 1/160. After some brief
research, I found that the 5D manual states that the sync for studio
strobes may be as low as 1/125 so I was relieved that it didn't indicated
any problem. My question is why the difference between the studio strobes
and a hotshoe flash? The obvious answer would seem to be the flash
duration, but on second thought, that can't be it, can it? I am using
Alien Bees B800s which supposedly have a flash duration that is 1/3200 or
so and even at half that, I didn't think that slow enough to cause a sync
problem. At full power many hot shoe flashes have a flash duration in
excess of 1/1000. What gives?

Eric Miller
www.dyesscreek.com

Not about flash duration, but all about signal propagation. It's all about
timing and how long the signal to "Fire the Flash" takes to get to the
flash. You can try rear curtain sync and see if that makes the problem go
away or makes it worse. You also mention using a wireless sync system to
shoot, that just adds to the likelihood of a delay.

On a side note make sure you look at the website on someone else's computer
or force the font to be one that supports the last 2 characters in your
sauce's name. I just get little squares.

-Jim

jimkramer wrote:
"Eric Miller" wrote in message
.. .
Since this subject is related to flash sync, I thought I'd ask it here. I
have been taking some product shots for a new website I will be launching
in a few weeks (it's actually up and running, but not much is there).
While taking my product shots, I noticed some shading of what should have
been an even background (different colored backdrops). I decided to lower
the shutter speed, because it looked like a sync problem.

Here are two photos that show the effect:

http://www.dyesscreek.com/hidden_pages/sync.html

On the left is a 1/200 exposure. On the right, 1/160. After some brief
research, I found that the 5D manual states that the sync for studio
strobes may be as low as 1/125 so I was relieved that it didn't indicated
any problem. My question is why the difference between the studio strobes
and a hotshoe flash? The obvious answer would seem to be the flash
duration, but on second thought, that can't be it, can it? I am using
Alien Bees B800s which supposedly have a flash duration that is 1/3200 or
so and even at half that, I didn't think that slow enough to cause a sync
problem. At full power many hot shoe flashes have a flash duration in
excess of 1/1000. What gives?

Eric Miller
www.dyesscreek.com

Not about flash duration, but all about signal propagation. It's all about
timing and how long the signal to "Fire the Flash" takes to get to the
flash. You can try rear curtain sync and see if that makes the problem go
away or makes it worse. You also mention using a wireless sync system to
shoot, that just adds to the likelihood of a delay.

On a side note make sure you look at the website on someone else's computer
or force the font to be one that supports the last 2 characters in your
sauce's name. I just get little squares.

-Jim


How can that be?? The images are images - pictures, no text as such.

Colin D.
** Posted from http://www.teranews.com **

Eric Miller wrote:
Since this subject is related to flash sync, I thought I'd ask it here.
I have been taking some product shots for a new website I will be
launching in a few weeks (it's actually up and running, but not much is
there). While taking my product shots, I noticed some shading of what
should have been an even background (different colored backdrops). I
decided to lower the shutter speed, because it looked like a sync problem.

Here are two photos that show the effect:

http://www.dyesscreek.com/hidden_pages/sync.html

On the left is a 1/200 exposure. On the right, 1/160. After some brief
research, I found that the 5D manual states that the sync for studio
strobes may be as low as 1/125 so I was relieved that it didn't
indicated any problem. My question is why the difference between the
studio strobes and a hotshoe flash? The obvious answer would seem to be
the flash duration, but on second thought, that can't be it, can it? I
am using Alien Bees B800s which supposedly have a flash duration that is
1/3200 or so and even at half that, I didn't think that slow enough to
cause a sync problem. At full power many hot shoe flashes have a flash
duration in excess of 1/1000. What gives?

Eric Miller
www.dyesscreek.com

It's a sync problem. The shutter is opening before the flash gets
going. It appears the second curtain is starting to close before the
flash has started, and using a slower shutter speed has delayed the
second curtain enough to catch the flash.

This effecr may be your cheapie radio link, or it may be characteristic
of Alien Bees. You could check the specs for any trigger delay in the
units, and this may be a reason for recommended slow speeds, even though
the flash itself may go off at 1/000 or shorter.

On the image of the bottle, both lamps are clearly reflected in the neck
of the bottle. I would try to eliminate that.
Colin D.
** Posted from http://www.teranews.com **

"jimkramer" wrote:

On a side note make sure you look at the website on someone else's computer
or force the font to be one that supports the last 2 characters in your
sauce's name. I just get little squares.


I get little squares in Internet Explorer, but a white question mark
within a black diamond in Mozilla Firefox.

Something definitely isn't right.

I like the sound of the sauce, though!

"That Rich" wrote in message
...
On Tue, 8 Jul 2008 23:27:51 -0500, "jimkramer"
wrote:

supports the last 2 characters in your
sauce's name. I just get little squares.

Uh...

*el* for bechemel.
or
*ce* for demi-glace
or
*se* for bordelaise
or
*ur* for chasseur
or
*ra* for madeira

Just trying to help.

Hope all is well in LA.

I reamain,

lover of French sauces,

RP©
-
If it doesn't have garlic in it, it's dessert



I thought that you were a Mexican cuisine aficionado? And where does garlic
flavored ice cream fall? :-)

The only real problems so far (aside from the heat & humidity) are the
roads. I came from NC (The good roads state, no kidding) and in MS they
have this "Yazoo Clay" that makes the roads turn into roller coaster rides.
Driving with a beverage is difficult and driving with a hot beverage is down
right dangerous.

-Jim

On a side note make sure you look at the website on someone else's
computer or force the font to be one that supports the last 2
characters in your sauce's name. I just get little squares.

-Jim




Yes, I have been having trouble with that. My style sheets are fighting me
at the moment. I am using Arial, which should support those characters -
"í®". It will be a few weeks before I can sell through the website so I
hope to work it out before then.

Eric Miller
www.dyesscreek.com

"Colin_D" wrote in message
...
jimkramer wrote:
"Eric Miller" wrote in message
.. .
Since this subject is related to flash sync, I thought I'd ask it here.
I have been taking some product shots for a new website I will be
launching in a few weeks (it's actually up and running, but not much is
there). While taking my product shots, I noticed some shading of what
should have been an even background (different colored backdrops). I
decided to lower the shutter speed, because it looked like a sync
problem.

Here are two photos that show the effect:

http://www.dyesscreek.com/hidden_pages/sync.html

On the left is a 1/200 exposure. On the right, 1/160. After some brief
research, I found that the 5D manual states that the sync for studio
strobes may be as low as 1/125 so I was relieved that it didn't
indicated any problem. My question is why the difference between the
studio strobes and a hotshoe flash? The obvious answer would seem to be
the flash duration, but on second thought, that can't be it, can it? I
am using Alien Bees B800s which supposedly have a flash duration that is
1/3200 or so and even at half that, I didn't think that slow enough to
cause a sync problem. At full power many hot shoe flashes have a flash
duration in excess of 1/1000. What gives?

Eric Miller
www.dyesscreek.com

Not about flash duration, but all about signal propagation. It's all
about timing and how long the signal to "Fire the Flash" takes to get to
the flash. You can try rear curtain sync and see if that makes the
problem go away or makes it worse. You also mention using a wireless
sync system to shoot, that just adds to the likelihood of a delay.

On a side note make sure you look at the website on someone else's
computer or force the font to be one that supports the last 2 characters
in your sauce's name. I just get little squares.

-Jim
How can that be?? The images are images - pictures, no text as such.

Colin D.
** Posted from http://www.teranews.com **

Near the bottom is the website address that he was taking the pictures for.
That site is where the font issue pops up.
-Jim

It's a sync problem. The shutter is opening before the flash gets going.
It appears the second curtain is starting to close before the flash has
started, and using a slower shutter speed has delayed the second curtain
enough to catch the flash.

This effecr may be your cheapie radio link, or it may be characteristic of
Alien Bees. You could check the specs for any trigger delay in the units,
and this may be a reason for recommended slow speeds, even though the
flash itself may go off at 1/000 or shorter.

The recommendation for slow speeds with studio flash comes from Canon,
though it may related to some triggering issue with the flash units. In any
event, I've never noticed the problem with hotshoe units triggered by the
same cheapie radio link (which seems to work flawlessly).


On the image of the bottle, both lamps are clearly reflected in the neck
of the bottle. I would try to eliminate that.

I initially had trouble with glossy labels that were reflecting the flash
units and used a light tent before just printing my own on plain paper for
photography purposes. The neck reflections are a little more troublesome
because of the curve at the bottom. I can remove the higher reflections by
raising the lights but the lower ones will still be there. I'll likely end
up shooting with the lights in multiple positions and then stitching
together a bottle with no reflections. Here is the current image as it
appears on the hot sauce website:

http://www.colibrihotsauce.com/

Eric Miller
www.dyesscreek.com

Eric Miller wrote:
Since this subject is related to flash sync, I thought I'd ask it here.
I have been taking some product shots for a new website I will be
launching in a few weeks (it's actually up and running, but not much is
there). While taking my product shots, I noticed some shading of what
should have been an even background (different colored backdrops). I
decided to lower the shutter speed, because it looked like a sync problem.

Here are two photos that show the effect:

http://www.dyesscreek.com/hidden_pages/sync.html

On the left is a 1/200 exposure. On the right, 1/160. After some brief
research, I found that the 5D manual states that the sync for studio
strobes may be as low as 1/125 so I was relieved that it didn't
indicated any problem. My question is why the difference between the
studio strobes and a hotshoe flash? The obvious answer would seem to be
the flash duration, but on second thought, that can't be it, can it? I
am using Alien Bees B800s which supposedly have a flash duration that is
1/3200 or so and even at half that, I didn't think that slow enough to
cause a sync problem. At full power many hot shoe flashes have a flash
duration in excess of 1/1000. What gives?

It's the trigger time from front-curtain open to the time the flash
actually firing.

I think the caption you put: "cheap wireless sync" is the problem.
Please DO name the brand.

The 'bees are not the problem.

Get PocketWizards. I've used them at 1/300 with no problem at all and I
would bet they would work well at 1/500 as well.

You can also get a pocketwizard compatible module for Sekonic meters (my
meter has the capability, but I haven't bought the module.

By the way, "Hummingbird" does not seem like a great name for a hot
sauce. Reddy-woodpecker would do it.




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