An illustration of what AG is talking about. This is what OMs (except
the 3Ti) can't do... manual exposure to capture and control the ambient
lighting of the background (calculated here to be a stop down) with TTL
flash taking care of the foreground (at correct exposure level). AG's
description of using multiple lights in the background doesn't change
anything in this equation except that he is controlling the background
ambient level (and the color temperature) to be more to his liking. Of
course, if you don't have TTL flash you can still do the same. You can
use flash auto mode or you can meter the subject under flash and control
the flash power manually.
<http://www.shootsmarter.com/index.php?option=com_content&task=view&id=175&acat=16>
Note that you may have to sign up on the smartshooter website to gain
access to this blurb. But that just gets you weekly blurbs like this
one and they don't sell your email address. Recommended if you do
people photography.
Finally, note that, even though the OM-2 will continue the exposure
beyond the flash if necessary, that's no guarantee that one will end up
with a good ratio of flash and ambient and the flash will be totally
ineffective at filling the far background due to the inverse square law.
Chuck Norcutt
Ken Norton wrote:
> Carlos, your assessment is very good. I agree with your technical notes.
>
> To a couple specific points: My OM-2S is particularily moody when it comes
> to TTL flash in Aperture-Priority Auto mode. If the ambient is 1/60 the
> flash may fire, but if it registers faster than 1/60 the flash will not
> fire. If I stop down the lens to drop the non-flash exposure to 1/60 or
> slower I am unfortunately reducing the effective flash-to-subject distance.
>
> I will specifically use flash with the ambient overexposing. This is common
> with outdoor portraiture where my subject is shaded, but the background is
> in bright sunlight. I'll usually overexpose the background by around a stop
> and let the flash properly expose the subject. With the original OM-2, this
> worked correctly because it could care less about the presence of a flash or
> not. However, the original OM-2 had another flawed characteristic--indoor
> shots.
>
> When shooting indoor weddings, for example, I like my room exposure to be
> one or two stops underexposed. If I was running everything manually, I'd set
> the aperture, for example at F5.6, and with ISO 400 film a PROPER ambient
> exposure would be 1/15. But with the OM-2n, OM-2S, OM-4(Ti), when shot in
> Auto-mode, the camera will override shutterspeed and force a 1/60 thus
> putting the background (ambient) two stops under exposed. The flash will
> fire, exposing the subject and the shutter-speed and aperture will
> effectively be fixed which keeps the background down. But with the OM-2, it
> is possible that not enough reflected light from the flash occured and the
> camera will drag the shutter longer which brings the background up AND ends
> up giving your subject too much mixed (flash + ambient) lighting and throws
> your colorcasts off.
>
> Why not forgo auto exposure and just use manual exposure you ask? Because
> if the flash does not fire, the auto-exposure will compensate and will still
> properly expose the image.
>
> The above description points to one of the most incredible usability
> features of the OM series. In Aperture-Priority, the exposure scale ALWAYS
> indicates what the exposure would be if the flash did not fire. Knowing that
> the camera will fire at 1/60 means that you just watch the scale and adjust
> aperture to put the needle or bargraph at the desired speed in relation to
> 1/60.
>
> I had an additional twist recently and it was something where the OM-3Ti
> gave me a capability I never had before with TTL-flash. I used the T45
> on-camera (or is it that the camera was on-flash?) and also used wireless
> triggers to fire monolight strobes up in the balcony. Because of the film
> used and the specific stage lighting, I was set at F4-5.6 and the shutter
> speed was 1/15 and 1/30 depending on the special effects of the lighting.
> The TTL flash (T45) was taking care of the subject, the strobes were filling
> in the rest of the stage about 1/2 stop down and the room/background
> lighting was either a stop high or a stop low depending on effects lighting.
> So, in essence I had THREE different sources of light I was working with and
> only one was TTL--which was quite important as my camera-to-subject distance
> varied from 5 feet to 50 feet. The results met and exceeded my expectations.
> Not a single exposure was off.
>
> As a side-note, the in-flash auto-exposure of the T45 works as well, if not
> better than OTF, except when under 10 feet from the subject. Olympus got the
> in-flash auto correct.
>
> AG
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|