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omd:flash_ttl

using the Olympus OM-D cameras with flash

troubleshooting

flash does not fire

  • ensure the flash is connected to camera properly
    • if using hotshoe make sure it is attached properly
    • if using PC sync outlet, ensure it is attached and PC sync cable is not faulty
    • if using Olympus RC mode, ensure it is configured correctly in camera and on the flash and that there is a master flash on the camera to command the remote flash
    • if using remote radio wireless flash with the Olympus OM-D cameras, check the transceiver and remote unit are configured correctly and communicating on the same channel / group
  • ensure flash is turned on and batteries are fresh enough to get the flash ready light lit up
  • ensure the flash flash ready light is lit up
  • ensure camera flash mode is not set to OFF or AUTO - I generally use “FILL IN”
  • if not using Olympus RC mode, ensure it is turned off in the camera
  • ensure camera drive mode is not a silent shutter mode
  • if using the bundled mini flash, ensure it is mounted correctly and not tilted down

exposure is too dark

  • if using TTL flash, ensure:
    • flash exposure compensation setting in the camera is not set to a too minus value
    • flash has adequate power to light up the scene for the camera's ISO and aperture setting
      • ensure you have removed any filters such as ND or polarising as these will need more flash power
      • consider using a wider aperture
      • consider using a higher ISO
      • consider using a more powerful flash or add in other flashes
      • NOTE if using super FP flash mode at fast shutter speeds, the maximal flash output is severely reduced with each stop of faster shutter speed
      • ensure flash output is maximised on subject - decrease the flash to subject distance if possible
      • if in doubt, change flash to manual mode, full output - if it is still too dark, either not enough flash output for settings and flash-subject distance, or, flash did not fire.

photo is over-exposed

  • if using TTL flash, ensure:
    • flash exposure compensation setting in the camera is not set to a too positive a value
    • main exposure compensation setting is not set too high
    • flash is not too close to subject (flash can only drop down to 1/256th of maximal output)
    • camera exposure mode is Aperture Priority (A on the PASM dial) and the scene ambient light is too bright for the fastest shutter flash sync speed (usually 1/250th sec) and that aperture, ISO combination in which consider some or all of:
      • set ISO to 100-200
      • add a ND or polarising filter to cut down the exposure
      • stop down the aperture to let less light in (but if you want the wide aperture for shallow depth of field (DOF), then consider using super FP flash mode which will allow faster shutter speeds to reduce ambient exposure level)

electronic flash capabilities

of the E-M5

  • hot shoe and bundled tiny flash
  • manual flash output levels 1:1 down to 1/64th - very handy
  • remote TTL flash with separate slave flash units
    • this is high speed sync flash technology initially invented by Olympus in the Olympus OM system and now is used by nearly every camera manufacturer
    • it allows shutter speeds to be used faster than the x-sync shutter speed, and thereby allows wider lens apertures and shallower depth of field (DOF)
    • as with all cameras, this technology is NOT useful for overpowering sunlight as unfortunately, the maximum flash light output decreases as the shutter speed gets faster
  • +/- 3EV flash exposure compensation
  • flash sync 1/250th sec with new flashes
    • flash sync defaults to 1/200th sec for FL-36R (or 1/160th sec when using this in RC mode)
    • you can use higher shutter speeds without resorting to SuperFP modes if you use a hotshoe adapter without TTL pins, but in this case your flash cannot use TTL metering, and it cannot determine ISO, aperture, focal length for zooming, but still this may be very useful as fill-in flash in bright sunlight up to 1/400th sec flash as long as your subject is only within the bottom 2/3rds of the frame (the flash does not expose the top of the frame as the shutter speed increases beyond 1/250th sec)

of the E-M1

  • as for the E-M5 BUT:
    • PC sync outlet available
    • flash sync 1/250th sec with MOST external flashes even in RC mode or radio remote TTL
      • you can use higher shutter speeds without resorting to SuperFP modes if you use a hotshoe adapter without TTL pins or connect via PC sync outlet, but in this case your flash cannot use TTL metering, and it cannot determine ISO, aperture, focal length for zooming, but still this may be very useful as fill-in flash in bright sunlight up to 1/800th sec flash as long as your subject is only within the bottom 2/3rds of the frame (the flash does not expose the top of the frame as the shutter speed increases beyond 1/400th sec)

using flash

manual flash

  • where possible, try using manual flash exposure instead of TTL flash as this has several advantages:
    • having your camera exposure mode set to Manual allows you to control the contribution of ambient light by adjusting the shutter speed (with the potential for going faster than the x-sync if the camera cannot detect a TTL-compliant flash)
    • having the flash mode set to manual allows:
      • avoidance of that really annoying pre-flash which can also delay the shutter release by a fraction of a second, cause subjects to blink or fly away
      • ensure you have consistent flash output from one shot to the next unlike with TTL flash which can give variable exposures - if your scene is stable in terms of flash to subject distance, etc, then once you have determined the correct flash output, you can just leave it and know it will be working fine
      • use of non-compliant flashes which you may have from other systems or from the old film days
      • use of radio remotely controlled flash with non-TTL radio remotes
      • teaches you about light intensity and how it changes with distance or bouncing off walls, etc
      • makes it easier to trouble shoot - too dark, just turn up flash output, camera ISO, or widen the aperture, do the opposite if too much flash
      • you can still use SuperFP mode in manual if you need to

normal fill-in flash

  • set camera flash mode to fill in flash
  • set camera PASM dial to Manual (you could use other modes but I like the full control over ambient exposure)
  • set flash to TTL
  • set aperture to your desired aperture for depth of field (DOF)
  • set ISO to 200 (or perhaps higher if you wish to get further flash reach or faster flash recycle times)
  • set WB to flash (or perhaps create a custom WB if bouncing the flash off a non-neutral surface)
  • adjust shutter speed to give you your desired ambient light exposure (must be slower than flash sync for the camera)
  • just set flash exposure compensation to a negative value depending on how little fill-in flash you want (eg. -0.7EV)
  • you can do this via the Super Control Panel (activate by pressing OK button, then use the arrow keys to get to flash +/- item, then OK again to select it)
  • if you are shooting in bright sunlight, you may wish to use a ND8 filter to allow wider aperture, or resort to SuperFP mode and a fast shutter speed

maximum output fill-in flash in bright sunlight

  • whilst you can use flash as is, at flash sync of 1/200th sec for older flashes or 1/250th sec for newer flashes such as the FL-600R, and you can use SuperFP mode to get faster flash sync (but at significant loss of flash output), there is a way to use your full flash output at fast shutter speeds if you are willing for a few compromises such as:
    • no TTL flash metering
    • no communication of ISO, aperture or focal length to the flash
    • the top part of the frame being increasingly unexposed by flash as shutter speed increases (half of the frame may be unexposed by flash at 1/640th sec)
  • the secret is just to put a flash adapter in the hotshoe which does not have TTL contacts, the camera will then allow you to set a shutter speed above the flash sync speed.
  • you will of course need to adjust the flash settings manually for the exposure you need.
  • don't forget if you want to shoot at wide aperture in bright sunlight with flash (not in SuperFP mode), you will need a ND filter to avoid over-exposure even at lowest ISO of 200 (or perhaps even at the “LOW” ISO setting of 100).
    • remember “sunny 16 rule” bright sunlight exposure at ISO 200, f/16 = 1/200th sec, at this speed, a ND8 3 stop filter will allow f/5.6
      • ND8 filter plus bump shutter to 1/400th sec as above, and you can use f/4 aperture and full output of the flash for fill-in

flash as main light with underexposed bright outdoor ambience

technique 1 - TTL independent compensation (default)

  • go to Menu, Custom Menu, Custom Flash and set flash (+/-) + (+/-) to OFF so that your flash exposure compensation is INDEPENDENT of ambient exposure compensation
  • set Exposure Compensation to a negative value (eg minus 1EV) to underexpose the background ambient light
  • set Flash exposure compensation to zero to give flash exposure of a normal exposure level

technique 2 - TTL flash, additive compensation

  • go to Menu, Custom Menu, Custom Flash and set flash (+/-) + (+/-) to ON so that your flash exposure compensation takes into account ambient exposure compensation
  • set Exposure Compensation to a negative value (eg minus 1EV) to underexpose the background ambient light
  • set Flash exposure compensation to a positive value opposite that of ambient compensation (eg. + 1EV) to return flash exposure to normal exposure level
omd/flash_ttl.txt · Last modified: 2018/12/13 21:21 by gary1

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