David Irisarri Vila wrote:
> Then, How can OM3Ti system work with OTF in manual mode (mechanical
> shutter)???
First, we where talking about the OM-4Ti which is a different camera
than the OM-3Ti.
> How can my OM4Ti meter the flash light comming from the
> F280 in manual mode, bacause there is no thyristor sensor?
Normaly it shouldn´t be able to do this, that´s was the manual says and
experience with my camera has teached me.
How the F280 works in AUTO full sync mode is not completly researched by
this list, but we have an theory I´ll quote later.
> If you have to work with slow shutter speeds with OM3Ti(with flash),
> Olympus brochure says OTF metering will work, giving you a high
> precision metering.
Yes, the OM-3Ti is a much smarter camera for fill-in-flash.
> No, in Manual mode is no OTF flash metering
>
> But Exposure compensation can reduce F280 power? Because I´ve taken
> five photographs from one subject with a strong backlit; I used 0
> comp, -1, -2, +1, and +2, asd the results were very impressive. You
> can see how is reduced f280 emission in -1 and how overflashes in +1.
> (I took them in AUTO mode with normal OTF)
True, as you said, in AUTO mode the exposure comp ring will afect
exposure, my answer was a bit short.
> exp. comp dial has no connection to the flash.
This was to short, I have to add, that there is an indirect connection
via the exposure electronics inside the camera, which controls the flash
output in AUTO mode.
> Then why OM3Ti uses exposure compensation if there isn´t any
> aperture priority program??? I´ve readed into a spanish magazine
> that exposure compensation in OM3Ti is coupled with F280.
You can use exp. comp. on every OTF capable cameras, but this will afect
overall exposure not only the flash, like in the OM-3Ti, where exposure
time and aperture is set by the user (it´s a full mechanical camera).
> > 3. With daylight, using SuperFP mode in order to take portrait with
> > short focal lenght (50mm) with wide apertures is nearly impossible
> > to avoid overflashing with slides; would it be possible to use,
> > exposure compensation in order to reduce flash emission, like with
> > normal OTF in AUTO mode?
>
> like above no connection, choose a larger distance, stop down, don´t
> use the 50mm/1.2 but the 100mm/2.0 ;-)
Maybe your problem was, that the fill in efect of the flash was not
strong enough, so you backlight has overpowered your exposure? In this
case an exp. comp. towards negative values might be helpfull.
> With the Metz a flash meter is not necessary, you can dial in every
> aperture
>
> Metz MZ-3 will work with f2 f4 and f8 apertures, but if you work with
> daylight is very difficult to know if you select some GN-value won´t
> overflash your picture. Do you think if I use this MZ-3 with OTF
> adapter will work properly with daylight???
Are you talking of the Metz 32 MZ-3? This flash has only 3 apertures to
choose in contrary to the Metz 40 MZ-3 (the flash I was thinking of)
which has 12 apertures to choose, sorry for the misunderstanding.
Richard
Now our preliminary results of our discusion how full sync flash works
in AUTO mode.
Any further information is appreciated. Is there someone from Olympus on
the list who could verify our theories or shed some more light on this
subject?
> Subject: Re: [OM] OTF light metering w / 280 Flash
> Date: Wed, 15 Apr 1998 22:02:56 EDT
> From: ONLYOLY BW <ONLYOLYBW@xxxxxxx>
>
> In a message dated 98-04-13 14:17:07 EDT,
> Richard you write:<< > << the image projected on the shutter curtain patern.
> Does the OM-3Ti have a pattern on the shutter curtain?
> Does it? If I remember right, there is no patern on the shutter.
> Snip!
> Well, I've got film in my 3Ti so I'll check the curtain in a few days and let
> you know.
> > Is there someone who knows how the FP exposure is calculated? >>
>
> OM-4Ti catalog says, that the flash time selection is coupled with the
> aperture.
> Snip!
> Yes, this is in the 4T 1984 catalog as well.
>
> Additionaly there is no way to change the FP flash output after the
> shutter has started.
> Snip! I Agree. I think??
>
> The conection with the aperture is necesary because otherwise there
> would be the danger of over flashing if the object is near, the aperture
> wide open and the shutter time relativly long (for expl. 1/80 in a dark
> stuation). The catch is, that the camera has no info of the aperture,
> just a relative info how many stops the lens will close.
> Snip! OK, I'm with you so far! So if I really want to screw this flash up,
> just shoot at close range with a wide open aperture?
>
> The FP flash time is always longer than the sync time, that sugest, that
> the flash starts before the shutter in Auto mode.
> An posibility for adjusting the FP flash output would be, that the flash
> starts after the mirror is up and the aperture has closed, mixing the
> flash light with ambient light.
> Snip!
> So the OTF meter would choose the power (20 ~40 milliseconds)of the flash?
> That would explain why the new 3Ti does not have this feature. It has to be
> set manually by using a guide# chart because it does not have OTF metering and
> probably fires at full (40 milliseconds) power?
>
> The OM-4Ti (OM-77AF and OM-707 too?) is now able to chose an shutter time
> which avoids overexposure. If the OM would measure the ambient light before
> the flash starts, it could balance flash light to ambient light.
>
> Snip!
> Am I right?
> YES, It is starting to make a little since.
> So, the OTF meter controls two(2) functions. 1) The power output of the flash
> (20~40 milliseconds) after the shutter opens and the aperture stops down. 2)
> The shutter speed will balance the ambient + flash light for proper exposure.
> Therefore, at close-up ranges (18 inches to 48 inches) the flash output can
> very according to the f stop chosen and ambient light controled by the OTF
> meter and a shutter speed will be chosen to balance exposure. This shutter
> speed could INCREASE(1/500 sec) or even DECREASE(1/60th sec) depending on the
> f stop, balance of the ambient + flash light and distance from lens.
> So, I should consider this Super FP mode with camera in Auto as a fill-in
> flash with scync speeds in the 1/60th to what ever, 1/125 or so. If I want to
> use higher shutter speeds ie. 1/1,000 or 1/2,000 second, then I will need to
> work out guide #'s distance/ f stop combinations for short close-up ranges
> with the camera in manual mode.
>
> Richard, Thanks alot for helping me "see the light " a little better. I owe
> you.
> The Not so Dummy Now!
> BW
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