Sigma EF-430 SUPER and EF-500 SUPER Photo Flashes
A digital photo has passed the time when an internal
flash was satisfactory. Today powerful additional flashes are on
the top. But they must be synchronized with the camera. I decided
to start description with flashes from Sigma, which is known as
a manufacturer of lens and attachments to cameras from other companies
(apart the production of its own photo cameras). The flashes under
consideration have almost the maximum set of possible functions
and a moderate price ($165 and $185 respectively). They are produced
in 4 versions: for cameras of Sigma, Canon, Minolta and Nikon. The
differences are connected both with pins in a hot shoe for quick
attaching of a camera, and with operation of auto system of definite
cameras.
We have tested the flashes designed for the cameras
from Canon. The 430 SUPER was tested entirely with the EOS
D30 and EOS 50, since the box contains the manual for the 430
ST, and the site
offers only superficial description of the camera's possibilities.
But the testing of the 430 was interrupted at the most interesting
moment because of problems in high-voltage circuit (according to
the service center). The Flash Servicing Center made a conclusion
about impossibility of the repair. Since the product was quite rare,
there was nothing to replace it with, and I had to wait for the
latest 500th model to continue the tests.
Main flash modes.
TTL. These flashes work with the Canon
cameras in the ETTL mode. The ETTL is a new way of exposure metering
when working with a flash. The exposure metering is implemented
according to the light reflected from an object and passed through
the lens. But while in the TTL mode the metering is implemented
during shooting according to the light, reflected from the film,
and an impulse broken after the camera receives enough light, the
ETTL mode deals with a preliminary flash to define exposure parameters
and necessary power of the flash. This mode appeared in the Canon
EOS Elan II cameras together with Speedlight 380 EX and 220 EX flashes
in 1995. A preliminary flash is used to estimate a signal until
a mirror of the camera is lifted up. The A-TTL mode also uses a
preliminary flash. But in this mode power of the flash is controlled
according to the light reflected from the film, and a pre-flash
is used to define a distance from an object and to calculate a necessary
aperture.
X synchronization with the first or second shutter.
A flash can be synchronized with the camera when a focal curtain
shutter is open completely according to the first or the second
shutter, i.e. in the first case the synchronization is being implemented
when the first shutter reaches an end of a frame, in the second
case - when the second shutter starts moving. You can set this mode
for a built-in flash by choosing a respective item in the menu of
the camera, but when an external flash is attached, the settings
of the camera are ignored and a synchronization type must be set
from the flash's menu. The Canon EOS D30 allows using this mode
only with the exposure equal to 1/30 or more. With the shorter exposure
the synchronization will be implemented always according to the
first shutter.
1/30s. Synchronization according to the first shutter.
The wheel rotates clockwise.
1/30s. Synchronization according to the 2nd shutter.
FP. Operation of the flash at short exposure
without a complete opening of the shutter is also possible. In this
case each part of the frame is exposed for a short time, e.g. 1/2000
s, while the opposite edges of the frame are exposed at the interval
equal to the time of a complete opening of a shutter, i.e. for the
cameras like Canon EOS 50 it is 1/125, and for the D30 it is 1/200.
I.e. if you need a "frozen" shot of a fast moving object, then you
must shoot at long exposures since an impulse of the flash is very
short, and if powers of the flash and surrounding light differ much,
the exposure will depend exactly on the duration of the flash. Synchronization
of the flash with short exposures is used far not for shooting of
fast passing events. This mode should be used when an illumination
level if high, and the flash is necessary only to lighten shadows.
By reducing the exposure, you also cut a contribution of the permanent
light into the exposure of the frame. The flash thus switches a
stroboscopic mode with a very high frequency (around 50 kHz), and
when passing a slit of the shutter each part of the frame is illuminated
with the flash. As a result, the total duration of an impulse will
equal a time of travel of the shutter along the frame (e.g., 1/200
s for the EOS D30), while each unit impulse lasts less than 1/ 50000
s.
FP synchronization. 1/4000 s. It is well noticeable
that different parts of the spoke were shot not at the same time,
that is why it looks like being curved.
X synchronization with the shutter being open entirely.
1/60 s.
This mode has become widespread not so long ago,
and many companies look at it as at some technical breakthrough.
But the history of synchronization on short exposures goes back
to 50s. The Zeiss Ikon Contax II A camera, released in 1954, had
an M-synchronization for a shutter speed equal to 1/30; X - for
1/50 and FP for 1/100 and shorter.
The flashes adjust a beam of light with a visual
angle of the lens with respect to its focal length within the
range of 28-105 mm. The flash shifts a source of light automatically
relatively to the Frensel lens in order to change an angle of the
beam of light. We can also set a split of the beam of light manually.
For operation with superwide-angle lenses the 430 flash is supplied
with an additional diffuser. The 500th model has it built in in
the case, and when you moves it out, a focal length equal to 17
mm is induced.
Shift of the lamp's head in a vertical plane
is implemented in both flashes. In the 500th model it is possible
in a horizontal plane as well. This way an object is illuminated
with the light reflected from a ceiling or a wall.
Flash power can be varied in the range up
to 1/16 of the full power of the 430 model and up to 1/128 of the
500.
A stroboscopic mode allows tracking phases
of motion of an object, the 430 model makes a series of flashes
at intervals of 0.1; 0.2; 0.5 and 1 s. This flash has a separate
stroboscopic mode for sports shooting. In this mode we have 18 flashes
at the interval of 0.02 s. This model allows setting the frequency
in the range from 1 to 199 Hz in 1 Hz steps.
Remote control. The flashes can be synchronized
with the camera without being connected with it with cables. In
this case the synchronization is implemented according to a light
pulse from the flash attached to the camera. If exactly the same
flash is attached to the camera, then the synchronization is implemented
not only in time but also in the power of the impulse. Data are
exchanged between the flashes via an IR channel (you can set 4 independent
channels). The system allows using up to three slave flashes in
an automatic synchronized mode and setting a ratio of energies of
their impulses. The absolute values of energies will be defined
by the auto system according to the exposure metering after a preliminary
flash.
If a built-in flash is used as master, we can watch
just a synchronous flash, the power of which can be set manually
up to 1/16(430) or 1/128 (500). The camera is equipped with a calculator
which shows at what distance and at what aperture an object will
be illuminated the required way. If a built-in flash works in the
ETTL mode, be careful since the Sigma flash may work from a preliminary
impulse. That is why I recommend you to use the AE-lock mode (a
button marked with an asterisk on the EOS cameras) to have a pre-flash
and to fix exposure parameters; when pressing a release button a
preliminary impulse won't take place any more.
One can also use the flash with cameras which have
only a standard 2-pin connector; in this case you should set the
mode of a distantly controlled slave flash, like in the case of
synchronization according to a light pulse.
Apart from the possibilities mentioned above, the
flash can be used for backlighting of an auto-focus in case of lack
of light. But there are some problems: the EOS D30 uses only its
own backlight for auto focus in all cases. It may be connected with
the color of the backlight: the Sigma and EOS 50 have it red, the
D30 has it white.
Besides, there is backlight for an LC-display to
control the flash in the complete dark.
Conclusion
These are super-automatic flashes at the attractive
price. They can be used in an automatic, camera-synchronized mode,
with the flash attached to the camera being capable of controlling
distantly of 3 more synchronized flashes. If necessary you can use
the flashes in a non-auto mode with the synchronization according
to the light pulse from a built-in flash of any camera, or connect
to a standard synchronizer of camera which do not support an auto
mode. But you must forget a stroboscopic mode in this case. The
flashes differ in power of an impulse. The leading number for the
430 is 43, for the 500 is 50.
The leading number makes possible to calculate
aperture which is necessary to be installed for the right exposure
when shooting on a film of 100 ISO. You must divide the leading
number by the distance to an object.
The second difference consists in a stroboscopic
mode. The 500 model allows setting the frequency from 1 to 199 Hz
in 1 Hz steps, and the 430 - 1, 2, 5, 10 and 50 Hz.
The third difference consists in a possibility
of rotation in a horizontal plane which is realized only in the
500 model.