Using flash outdoors
- see also:
- on the net:
- triggering flashes:
- Quantum wireless-enabled flashes for Nikon/Canon/Olympus/etc:
- Metz flash
- flash photography with Canon EOS cameras:
- flash light meters:
- safety of legacy flash units - the issue of high trigger voltages
potentially damaging your camera:
- using Nikon SB800 flash wirelessly:
- natural looking flash:
Using flash outdoors:
- unless you have a battery operated studio flash, you will need to resort
to electronic flash units either on camera or off-camera.
- if using multiple flash units or remote off-camera, then you have several
options of how to trigger and control them:
- infrared wireless TTL control:
- most camera manufacturers now have systems that allow their TTL
exposure control to work wirelessly via infrared messaging from
either the camera's inbuilt flash/messaging system (eg. Olympus) or
more usually via a master flash unit attached to the camera hotshoe
(directly or via a TTL cord) or a IR wireless transmitter that sits
in the hotshoe (eg. Canon, Nikon).
- such systems can make life much easier in controlling a number of
flashes and usually allow flashes to be grouped into any one of
three groups (A,B,C) and to avoid interfering with other
photographer's systems, can be assigned to one of four IR channels.
- the major downside to these systems is the requirement that the
flashes' sensors are in a line of sight from the transmitter, which
usually mean they must be in front of the camera within an arc of
+/- 30deg (50deg for Olympus) with this arc becoming narrower the
further away the flash unit is.
- there is a new product coming out that converts the IR signals
into radio signals to get around these limitations, I am not sure
why the camera manufacturers did not create it this way in the first
place.
- radio wireless TTL control:
- as for infrared but uses radio waves and thus more distance and no
need for line of sight
- Quantum flash
- QF5d-r flash unit (~$A1265) + QTTL on-camera module specific
for camera (~$A235)
- remote wireless TTL only for supported Canon/Nikon dSLRs, not
yet for Olympus remote TTL.
- RadioPopper:
- non-TTL optical triggering:
- just purchase a optical trigger and connect it to each remote
flash and they will fire the flash when they detect a flash firing -
thus you must be able to trigger one of the flashes directly for
this to work.
- exposure control is via each flash unit's own sensor or using
manual output settings.
- non-TTL radio triggering:
- as for non-TTL optical triggering but requires a radio transmitter
on the camera hotshoe (can usually select one of four or eight
channels depending on model to avoid interfering with other
photographers), and radio receivers which attach to each flash.
- exposure as for non-TTL optical triggering.
- advantage is no need for line of sight and much further distances
between flash and transmitter possible.
-
wireless radio slaves:
- consider options to soften the light by diffusing it through a white
umbrella held close to the subject, or bouncing the light off large white
reflectors.
- consider options to give spot effect using snoots or honeycomb grids.
Outdoor portraits with flash:
- flash as a fill-in only for ambient lighting:
- TTL auto methods:
- set camera flash mode to appropriate setting:
- Nikon - balanced fill TTL
- Canon - ETTL then set flash exposure compensation to - 1/3EV
to -2/3EV according to desired fill
- Olympus - TTL then set flash exposure compensation to - 1/3EV
to -2/3EV according to desired fill
- expose for ambient light as usual
- high speed sync (FP) TTL flash methods:
- in bright sunlit subjects, there are times when you want to use a
wide aperture to give shallow depth of field, but this means you
will end up with needing ISO 100 and a fast shutter speed, too fast
for normal flash sync (which is usually 1/180-1/250th sec depending
on camera).
- Olympus invented a system to address this issue which allowed
flash to sync at almost any shutter speed BUT at the expense of much
reduced flash output. This capability is now supported by most
manufacturers.
- set camera flash mode to appropriate setting:
- Nikon - balanced fill TTL
- Canon - ETTL then set flash exposure compensation to - 1/3EV
to -2/3EV according to desired fill
- Olympus - TTL then set flash exposure compensation to - 1/3EV
to -2/3EV according to desired fill
- expose for ambient light as usual - aperture priority or manual
with wide aperture set +/- ND or pola filter
- flash as main light with ambient background exposed to effect:
- TTL auto methods:
- set camera flash mode to appropriate setting & ensuring
flash exposure compensation set to 0 EV:
- Nikon - i-TTL
- Canon - ETTL
- Olympus - TTL
- expose for ambient light for desired effect, either by:
- aperture priority auto exposure:
- set exposure compensation (not flash exp. comp) to
whatever level you desire for effect, eg. -1EV will
underexpose the background by 1 stop to give emphasis on the
subject who will be lit by the flash.
- manual exposure:
- this ensures you have full control over aperture and
shutter speed
- set shutter speed to flash sync speed or slower
- adjust aperture so that ambient scene will be
under-exposed
- Manual method:
- set camera and flash to manual exposure modes, set camera shutter
to flash sync speed (eg. 1/180thsec)
- if you don't have access to a flash meter, and you are using
digital then trial and error is a useful technique.
- start off with a guesstimate setting for your flash output,
distance to subject, ISO, aperture
- take a series of photos and check results, each time getting
closer to your desired main light exposure until you have it exactly
right (check your dSLR histogram on the LCD).
- then adjust the shutter speed slower than the sync speed to give
the ambient background effect you are looking for, if at the sync
speed the ambient is too bright you need to try one of the
following:
- use high speed sync (FP) if available and flash output
sufficient
- close down the aperture and increase output of flash or move
it closer.
- now for more efficiency, you might first start with getting your
ambient exposure to what you need within your flash sync shutter
speed range then deal with the flash exposure by adjusting its
output or distance to subject.
Creative techniques:
- use an orange gel on your flash outdoors or even indoors lit by
daylight:
- this gives you ways to deal with poor lighting or when your sunset
doesn't eventuate or disappears.
- set camera WB to tungsten, underexpose for ambience and you have a
cool blue saturated ambient background which contrasts nicely with a
warm to neutral subject.
- set camera WB to daylight, and you get warm, sunset effect
highlights from your flash.
- see: