Ok, just checked the G-40 spec., seems that it is not a TTL flash.
Based on what I have read from ESIF, I try to explain a bit more:
G40 has four mode, IVP, Auto, Fixed GNs, Multi-strob.
IVP- The camera set the flash power according to the aperture, focus
distance and ambient light. Something like flashmatic.
Auto - Aperture information is sent to the flash by the camera, the
flash control output by the built-in sensor. Just like normal auto
flash you can buy everywhere, the different is you are no need to dial
in the aperture info on the flash itself.
Fixed GN is very simple, no need to explain and Multi-strob is non
related to the discussion.
FL40
TTL auto - A pre-flash is issued and the CCD detect the light
intensity, the camera calculate the power required and issue command
to the flash.
Normal auto - Aperture is set on the flash like all common auto
flashes. Output power is control by the flash built-in sensor.
Fixed GN - Same as above.
May be it still make no different to a users as they just know they
will get accurate flash every time.
I can only say if you want to design a flash that can be used on a
1990 designed film camera and a 2001 designed digital camera it can be
done. Although both G-40 and FL-40 are computer flashes but they are
totally different.
C.H.Ling
"George M. Anderson, Photographer" wrote:
>
> What I'm saying is (and I'm comparing to IS-3/G-40, not T series) is that
> the camera signals the flash to fire, whether it's preflash or real flash.
> There's no reason it can't use the same hot shoe contact and signal level to
> do that on the G-40 and the FL-40. It doesn't matter for this whether
> there's a CCD or film receiving the light. Or so it seems to me.
>
> George
>
> > -----Original Message-----
> > From: owner-olympus@xxxxxxxxxxxxxxx
> > [mailto:owner-olympus@xxxxxxxxxxxxxxx]On Behalf Of C.H.Ling
> > Sent: Wednesday, January 15, 2003 7:17 PM
> > To: olympus@xxxxxxxxxxxxxxx
> > Subject: Re: [OM] E-20 and G-40
> >
> >
> > Sorry, in T-series flash there is no preflash, the flash just fire and
> > the camera tell it to stop when light is enough. It may make no
> > different to most people but to a electronics engineer it makes big
> > different.
> >
> > C.H.Ling
> >
> > "George M. Anderson, Photographer" wrote:
> > >
> > > Thanks, Dave. and C.H.
> > >
> > > The G-40 zooms with the IS-3 lens too.
> > >
> > > According to C.H. there's a preflash done with the FL-40 so CCD can
> > > determine exposure. Again though, I don't see why you'd need different
> > > electronics - same principle: tell the flash to fire, measure
> > the light. Who
> > > cares if it's FL or G ?
> > >
> > > George
> > >
> > > >
> > > >
> > > > I have an E-20 and the FL-40 flash. The G-40 might work, I don't
> > > > know. But
> > > > the FL-40 not only does TTL and other standard functions as you would
> > > > expect, it zooms in and out as you zoom the lens on the E-20.
> > I am very
> > > > happy with the results using the FL-40 in conjuntion with the
> > > > built-in flash
> > > > on the E-20.
> > > >
> > > > If you have a G-40 and an E-20 you can readily try it out as
> > the result
> > > > will be evident on the LCD.
> > > >
> > > > Dave Dougherty
> > > >
> > > > If you
> > > >
> >
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