Olympus-OM
[Top] [All Lists]

[Fwd: [OM] Why Oly is in a hole / screens & 280 flash]

Subject: [Fwd: [OM] Why Oly is in a hole / screens & 280 flash]
From: John Hermanson <omtech@xxxxxxxxx>
Date: Sun, 19 Jul 1998 12:10:45 -0400
Resent
--- Begin Message ---
Subject: Re: [OM] Why Oly is in a hole / screens & 280 flash
From: John Hermanson <omtech@xxxxxxxxx>
Date: Fri, 17 Jul 1998 14:49:25 -0400
Since the flash in Super FP mode is actually a number of short burst, lasting a
period of time long enough for the curtains to complete their travel, the camera
would have to control each short burst individually, during the exposure (which 
it
can't).

John

Shawn Wright wrote:

> On 17 Jul 98 at 11:17, ONLYOLYBW@xxxxxxx wrote:
>
> >  Hans wrote;
> >  The support for Super FP, using the F280 flash is a feature of the 3Ti,
> >  next to TTL flash support, but it works differently compared to the
> >  4Ti, since the camera can only control (cut off) the flash (which can
> >  be done both in TTL and in Super FP mode),
> >
> > SNIP!
> > Hans, I believe you are incorrect here.  In my experience the 3Ti will not
> >  "cut off the flash" in Super FP mode, only in TTL mode.  If it did, Olympus
> >  would not tell us on page 43 of the 3Ti instruction manual to "Select the
> >  shutter speed between 1/2000 and 1/60 sec. and aperture according to the 
> > chart
> >  on the left".
> >
> Speaking as one who's never even *seen* either a 3Ti or a 280, I'd have to say
> that Hans view doesn't *sound* correct either, according to my understanding 
> of
> the F280. If the 3-Ti could turn off the flash in FP mode, as it does in TTL
> mode at 1/60 or less, this would result in part of the frame receiving *no*
> flash exposure if the shutter is above 1/60 (why else would one use FP mode).
> It's my understanding that the whole point of FP is that the flash consists of
> many short bursts such that they appear as a continuous light source to the
> film, even at 1/2000 sec. Cutting off the flash (as TTL does) would reduce the
> FP mode to TTL-equivalent, and its inherent limitation of approx 1/60 max
> shutter speed.
>
> That said, I suppose this must mean that the 4-Ti /F-280 must calculate the
> required FP flash intensity/shutter speed prior to exposure, since varying
> *either* of these values during exposure would also result in uneven exposure
> across the film plane. (again assuming shutter speed above 1/60)
> Which explains why the 4Ti *cannot* vary the shutter speed during exposure.
> (although the ability to adjust exposure compensation on the 4T with and
> without flash compensation sure would be nice, for adjusting fill ratios. It 
> is
> also my understanding that the F280 does nothing to help us easily adjust fill
> ratios; this is the main reason I haven't sought one out).
>
> Any corrections to my above thoughts appreciated...
>
> ========================
> Shawn Wright
> Computer Systems Manager
> Shawnigan Lake School
> 250-743-6240
> swright@xxxxxxxxx
>
> < This message was delivered via the Olympus Mailing List >
> < For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
> < Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >




--- End Message ---
<Prev in Thread] Current Thread [Next in Thread>
  • [Fwd: [OM] Why Oly is in a hole / screens & 280 flash], John Hermanson <=
Sponsored by Tako
Impressum | Datenschutz