Basic Minolta flash questions
 

Hi -

If the camera (Maxxum 7) is set to f/8 in A-mode, does setting the
flash (5600 HS) compensation dial to +1 change the flash output to
f/5.6 or f/11? (My guess is the former). Flash is in TTL-mode.

Why does the flash range (as shown on the flash's display panel)
decrease when setting flash compensation to +1? If the flash is
putting out more light, shouldn't the range increase rather than
decrease? To put it another way, if the flash output is changed to
f/5.6, dividing the GN by 5.6 results in a bigger number (distance)
than does dividing by 8.

Thanks for any help in advance.

Dave

Basic Minolta flash questions
 

Dave Yuhas wrote:

Hi -

If the camera (Maxxum 7) is set to f/8 in A-mode, does setting the
flash (5600 HS) compensation dial to +1 change the flash output to
f/5.6 or f/11? (My guess is the former). Flash is in TTL-mode.

Neither. When shooting TTL flash you are asking the TTL flash
meter to decide when to shut off the flash. By setting +1 you
are telling the meter to flash-expose 1 stop more than if the
flash were reflecting off of an 18% grey target.

If 18% grey, aperture f/8 and flash comp +1, then the flash
output would be as if for f/11.

If the scene were 18% grey, and your aperture were f/8, 0 flash
comp then the flash output would be f/8.

Without compensation, if the target was black, the flash would
tend to run about 2 stops too long; if white, about 2 stops too
short. Flash comp allows the photog to compensate for these
scene differences. It is of course harder when the scene is
composed of mixed elements.

[Note that when manually setting a flash using a flash incident
meter, you ignore the reflectivity of the scene and set the
flashes according to the aperture desired, with the lights, at,
below or above that setting according to the desired effect.]


Why does the flash range (as shown on the flash's display panel)
decrease when setting flash compensation to +1? If the flash is
putting out more light, shouldn't the range increase rather than
decrease? To put it another way, if the flash output is changed to
f/5.6, dividing the GN by 5.6 results in a bigger number (distance)
than does dividing by 8.

The max range displayed on the flash is based on the GN of the
flash and the selected aperture. the min range on the ability of
the flash to stop flashing when signalled to do so by the
TTL-flash meter.

The camera assumes that you are increasing/decreasing flash comp
in order to correct for the meter misreading the returned light.
The assumption is that the target is 18% grey.

If you are increasing the flash comp, it is because you believe
the scene is so light as to fool the flash-meter into
underexposure. So if you need to increase the compensation v.
the meter, the effective range of the flash is LESS for the
current scene, not more.

Remember that TTL-flash works on the reflectivity of the scene
during exposure to decide whan to stop the flash. This is
opposite to how you set studio lights with an incident meter.

Hope the above makes sense and helps.
Cheers,
Alan

--
--e-meil: there's no such thing as a FreeLunch.--

Basic Minolta flash questions
 

Alan -

First of all, thanks for the lucid explanation. If I may, let me ask
one, make that two, more questions to make sure I've got this
right...

1 - With TTL, If I'm photographing a bride in a white dress, and the
dress takes up a major proportion of the frame, I should increase
flash compensation to insure the dress looks white in the final print?

2 - If I place a diffuser on the flash, flash compensation is not
necessary because TTL will compensate (as long as I'm not pushing the
outer limit of the flash range)?

Dave

On Sat, 26 Jun 2004 11:11:13 -0400, Alan Browne
wrote:

Dave Yuhas wrote:

Hi -

If the camera (Maxxum 7) is set to f/8 in A-mode, does setting the
flash (5600 HS) compensation dial to +1 change the flash output to
f/5.6 or f/11? (My guess is the former). Flash is in TTL-mode.

Neither. When shooting TTL flash you are asking the TTL flash
meter to decide when to shut off the flash. By setting +1 you
are telling the meter to flash-expose 1 stop more than if the
flash were reflecting off of an 18% grey target.

If 18% grey, aperture f/8 and flash comp +1, then the flash
output would be as if for f/11.

If the scene were 18% grey, and your aperture were f/8, 0 flash
comp then the flash output would be f/8.

Without compensation, if the target was black, the flash would
tend to run about 2 stops too long; if white, about 2 stops too
short. Flash comp allows the photog to compensate for these
scene differences. It is of course harder when the scene is
composed of mixed elements.

[Note that when manually setting a flash using a flash incident
meter, you ignore the reflectivity of the scene and set the
flashes according to the aperture desired, with the lights, at,
below or above that setting according to the desired effect.]


Why does the flash range (as shown on the flash's display panel)
decrease when setting flash compensation to +1? If the flash is
putting out more light, shouldn't the range increase rather than
decrease? To put it another way, if the flash output is changed to
f/5.6, dividing the GN by 5.6 results in a bigger number (distance)
than does dividing by 8.

The max range displayed on the flash is based on the GN of the
flash and the selected aperture. the min range on the ability of
the flash to stop flashing when signalled to do so by the
TTL-flash meter.

The camera assumes that you are increasing/decreasing flash comp
in order to correct for the meter misreading the returned light.
The assumption is that the target is 18% grey.

If you are increasing the flash comp, it is because you believe
the scene is so light as to fool the flash-meter into
underexposure. So if you need to increase the compensation v.
the meter, the effective range of the flash is LESS for the
current scene, not more.

Remember that TTL-flash works on the reflectivity of the scene
during exposure to decide whan to stop the flash. This is
opposite to how you set studio lights with an incident meter.

Hope the above makes sense and helps.
Cheers,
Alan

Basic Minolta flash questions
 

Dave Yuhas wrote:

Alan -

First of all, thanks for the lucid explanation. If I may, let me ask
one, make that two, more questions to make sure I've got this
right...

1 - With TTL, If I'm photographing a bride in a white dress, and the
dress takes up a major proportion of the frame, I should increase
flash compensation to insure the dress looks white in the final print?

Yes. Depending on the proportion in the image frame, +1 to
+1.5. If the groom (charcoal) and the bride are together, it may
or may not be quite a wash ... it's always hard to outguess the
flash exposure system... incident meter when you can.

note: read your camera manual regarding metering with flash; esp
if you have mixed elements in the scene and you are using only
the center AF spot depsite subject being to the side. On my
Maxxum 9, flash metering is weighted to flash-meter element
corresponding to to the AF selector. You can force scene-average
by holding the DOF preview button (on the Max-9, anyway). A
custom function can also force even weighting.

Assuming negative film and that you may be 'rating' it 2/3 over,
you might want to knock half a stop off the flash comp to
maintain details in the whites.


2 - If I place a diffuser on the flash, flash compensation is not
necessary because TTL will compensate (as long as I'm not pushing the
outer limit of the flash range)?

Precisely so; and to help out (avoid the upper limit) 'give' the
flash another 1.5 stops of aperture if appropriate... about a
wash for a small difuser (if you have an incident flash meter you
can quickly determine how many stops are lost... if you mean a
sto-fen then this factor is a bit variable depending on the room
you're in)

Note, for critical work, and when I have the time, I make flash
incident readings and control the flash manually (5600HS, 5400HS)
which can be done wireless as well as on camera.

Cheers,
Alan

--
--e-meil: there's no such thing as a FreeLunch.--

Basic Minolta flash questions
 

Note, for critical work, and when I have the time, I make flash
incident readings and control the flash manually (5600HS, 5400HS)
which can be done wireless as well as on camera.

Please tell me which flash meter you use. I have the 5600HS(D); to
date I've found no way to use it with a flash meter. I can't, for
example, connect it to my Minolta Spotmeter F. The flash does not
have a standard sync connecter.

Thanks for your help.

Dave

Basic Minolta flash questions
 

Dave Yuhas wrote:

Note, for critical work, and when I have the time, I make flash
incident readings and control the flash manually (5600HS, 5400HS)
which can be done wireless as well as on camera.


Please tell me which flash meter you use. I have the 5600HS(D); to
date I've found no way to use it with a flash meter. I can't, for
example, connect it to my Minolta Spotmeter F. The flash does not
have a standard sync connecter.


You have to use a flash meter that has an auto (or non-cord) mode
that detects the flash going off. Thence set the flash manually
as needed, using the TEST button to fire and check the meter
reading. The Spotmeter F does not have this non-cord
capability... (See my replies to you of June 16).

I use the Minolta Auto Meter VF meter, which I don't reccomend as
the non-CORD mode requires that you reset it by hand each time
which is a pain when setting lights. (It can also be used with a
sync cable of course) A real "auto" flash meter that detects and
reports each occurance of flash would be much better. (I still
regret selling the Sekonic 508L, sigh).

Cheers,
Alan



--
--e-meil: there's no such thing as a FreeLunch.--