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.
--
What if the Hokey Pokey *IS* what it's all about?
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