Chip's off-list request for clarification prompts correction of a follow-on
posting for a different effect using similar methods. This is the
*corrected* set of instructions giving the proper direction to turn the EV
compensation ring. An apology for any confusion the original may have caused:
------------------------------------
There is another effect you can achieve with dedicated flash and TTL OTF
metering outdoors. It takes slightly more work and unlike "fill" flash
this would be better classified as "overfill" flash as it seeks the
opposite ratio of ambient to flash than fill flash would.
Given a frontlit subject significantly closer than an equally lit distant
background you can highlight the subject and reduce the background
brightness with flash. This can be used to reduce the distraction of the
background in the photograph or achieve a darker background if one is
desired, but the subject cannot be positioned in front of one.
1. Set the camera for *twice* to *four times* the ASA rating of the film
and Auto mode.
2. Bolt the flash unit on to the camera and leave it OFF.
3. Aim at the subject, focus, and with the flash *off* set the aperture
ring until you get a shutter speed of 1/60th.
4. Turn on the flash unit on (in TTL auto mode).
5. Turn the compensation ring in the *PLUS* direction until you have
compensated for the "push" you set the camera to in #1. (for twice the
ASA, use +1; for four times the ASA, use +2; etc.)
6. Shoot the photograph(s) and repeat 3 - 5 if lighting changes.
7. Remember to reset the EV compensation ring and ASA dial when you're
finished!
This does the *opposite* of a fill ratio by setting up for more of the
light coming from the flash and less from ambient sources. What you have
done is set the exposure for ambient lighting one to two stops underexposed
at 1/60th second. Since the flash locks the shutter speed to 1/60th the
background, especially if it is significantly farther away, will remain
underexposed (darker). Recorrecting using the compensation ring allows the
TTL metering to provide correct flash exposure for the closer subject.
This is a bit trickier than using the flash for fill and may require more
experimentation with a victim, uhhhh subject, to get a feel for what the
results will be and/or some "bracketing" with several exposures when
wanting to achieve this effect with a real subject. It also may be *very*
difficult (impossible?) if you use faster films as you can easily run out
of stops when closing down the aperture to get a 1/60 shutter speed. [Oh
goody, this is the excuse I've been needing to justify buying those ND
filters!] It also requires the subject to be significantly closer than the
background or you will end up with everything more or less equally exposed.
---------------
Additional notes not in the original.
a. Ensure your subject fills a sufficient part of the frame to be the
greatest influence on the center-weighted metering. Otherwise you can end
up with the same washed-out subject as a normal flash photograph (in Normal
Auto or TTL Auto) with a small subject and an infinitely far background
that does not reflect enough light back to the camera/flash.
b. You can use less than twice the ASA, although the effect will be
diminshed accordingly. Twice the ASA will underexpose the background by up
to one stop and four times the ASA will underexpose the background by up to
two stops (depending on how close the backgound is to your subject and
therefore how much light it receives from the flash). The latitude of the
film you use may affect your choice in this also.
-- John
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