Olympus-OM
[Top] [All Lists]

Re: [OM] Panasonic, EFC and flash (or lack therof), was: Now THIS is ne

Subject: Re: [OM] Panasonic, EFC and flash (or lack therof), was: Now THIS is news!
From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
Date: Mon, 18 Aug 2014 15:39:08 -0400
I also thought about the rolling aspect of the shutter curtains but don't think an instantaneous EFC combined with a mechanical and rolling second shutter is the problem you think it might be. Since the E-M1 has a 1/8,000 second shutter speed I think the curtains can move at a speed that is fast relative to the 1/320 maximum sync speed. Granted, the 1/8,000 speed is formed by a narrow moving slit but that slit has to be moving very fast.

Fast sync speed is required for daylight fill flash. Even 1/320 may not be speedy enough to avoid ND filters or the use of sputtering flash units. (Oly's "FP" flash mode).

Chuck Norcutt


On 8/18/2014 12:50 AM, Moose wrote:
On 8/17/2014 3:10 PM, Chuck Norcutt wrote:
I didn't ask Panasonic but did do a Google search and found this
thread on DPReview. <http://www.dpreview.com/forums/post/53437183>

In a nutshell, Panasonic's implementation of Electronic First Curtain
is a "rolling" implementation... as though the curtain is moving
across the sensor.  It is unlike the E-M1's implementation which is
apparently nearly instantaneous.

This post doesn't seem to me to be entirely accurate.

This stuff is a bit obscure as yet, so tricky. Doesn't first curtain
have to be rolling? Above the highest speed at which both curtains are
fully open at once, roughly flash sync speed, exposure with a mechanical
shutter is with a moving slit.

If an electronic shutter EFC is instantaneous, and the second curtain is
mechanical, exposure will vary widely across the frame, no? I think the
E-M1 may have a much quicker second curtain than the tiny, stepper motor
driven, single curtain of the GM1, but first curtain would still need to
'roll'. And that rolling must be pretty well the same speed as the
second curtain moves, for even exposure.

The net is that the E-M1's EFC shutter is fully open for all flash
sync speeds up to 1/320.  The Panasonic EFC shutters are only open
during the long end of the sync speeds... 1/10 to 1/25 depending on body.

1/50 sec. on the GM1. I think he is talking about earlier bodies. As
that function isn't available on the GX7, there's no spec. :-)   I don't
know anything about other EFC Pannys.


But wait.  Sounds good but doesn't explain why there is no flash at
all with your Panasonic's EFC on

I was less than precise. True of the GX7. The GM1 has flash, sync speed
1/50, with EFC, in fact, there is no mechanical first curtain. In Silent
Mode, flash is forced off.

This link from Mike's post is very useful on this subject.
<http://www.imaging-resource.com/PRODS/panasonic-gm1/panasonic-gm1TECH.HTM>

... unless you haven't tried flash at those less useful... umm, slow
speeds.

I just don't require the same things from flash that you do. I can't
recall the last time I used outdoor fill, probably automatic with T32 in
OTF/TTL over 25 years ago.

For static things and relatively slow moving people posing, 1/50 is just
fine.

Dr. No Flash*

* Well, HARDLY ever.

--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz