Archived posting to the Leica Users Group, 2006/12/26

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Subject: [Leica] Best flash for M8?
From: telyt at earthlink.net (Douglas Herr)
Date: Tue Dec 26 19:49:05 2006
References: <015201c72967$575447e0$6401a8c0@FrankDell2>

Frank, it would make no sense to limit flash sync to 1/250 sec if the 
shutter isn't providing the exposure timing.  If the shutter were 
functioning only as a dust cover and the exposure duration were 
determined only by an electronic signal control a flash sync could be 
provided at 1/8000 sec.  Of course there are contrarians on this list 
who might claim the 1/250 sec limit is another example of Leica's 
engineering incompetence when 1/8000 sec is possible.

Doug Herr
Birdman of Sacramento
http://www.wildlightphoto.com


On Dec 26, 2006, at 7:30 PM, Frank Filippone wrote:

> OK.. I went there and read the following under M8 tech specs at the 
> Leica USA site....
> ---------------------
> To  quote.......
> Shutter:
> Micro-processor controlled metal-blade slotted shutter with vertical 
> movement.
> Shutter Speeds
> In automatic mode (A) steplessly from 32 s to 1/8000 s. Using manual 
> setting 4 s to 1/8000 s in half steps.
> B for long exposures of any duration.
> Shutter action optimized for minimum noise. Driven by an electric motor
> --------------------
> Having read that, I will repeat that the shutter in the M8 is only for 
> a dust ( and overload) sensor cover.  It does nothing for the
> exposure.  Let me explain.....
>
> The sensor is gated fully under electronic digital control.  It has 
> nothing to do with a mechanical part anywhere in, round or under
> the camera.  It is both easier to do it this way, it works, it needs 
> no calibration, and it is cheap to make.  It is totally
> electronic.
>
> The shutter COVER, or what you might call a shutter, does not do 
> anything to the exposures.  If it did, Leica would have to make an
> infinitely variable shutter accurate to 1/8000 of a second, and keep 
> it in calibration.  Ain't going to happen.  Nikon proved that
> in the 8008 and other cameras.
>
> I think it is important that users know what they are getting in an M8 
> or other digital camera  ... this mechanical shutter is
> probably ( maybe, maybe not) timed to open and close in some 
> relationship with the exposure.  It does not matter how long the
> shutter is open; as long as it is long enough for an exposure to be 
> recorded.  It can be a LOT longer    the light is gated by a
> digital signal, not a mechanical device.  Very similar to the baffle 
> shutter in a Hasselblad 500 series.
>
> Notice carefully that Leica never claims that the shutter speed is 
> mechanical nor do they claim the shutter is timed for any time
> duration...   They claim the shutter is a vertically moving metal 
> blade slotted shutter.  The shutter speeds are the ones that are
> timed with specs on them.  There is a big difference between the 
> shutter speeds that affect the exposure, and the shutter that only
> covers the sensor.  What I called a baffle.
>
> dPreview does not add any information.  I am sure they are nice guys, 
> but technically,  anyone that claims the reason a M8 can have
> higher synch speed than a M7 is because of a different shutter is just 
> plain not correct.   The synch is digitally controlled as are
> the gating functions of the sensor.  There is no mechanical 
> association in a M8.  There is in any previous film oriented M ( or
> LTM)..
>
> BTW, if you owned a M8, you could easily prove me wrong....   Try the 
> shutter at different speeds with no lens.  You should see the
> light baffle open and close faster with increasing speed, like a real 
> shutter does.  You do not have to be 100% accurate, you only
> need to note if the thing stays open longer with increasing exposure 
> time....  It should be pretty obvious.
>
> If there is some evidence that the M8 has a mechanically timed 
> exposure, I still have not seen it......If you, or someone else on
> this list,  own a M8, check out the shutter /baffle/ whatever you want 
> to call the thing that moves out of the way to allow the
> light to hit the sensor. Then we have some form of data that is not 
> marketing speak.....
>
> I would promise to eat a bug if I am wrong, but Cal Worthington has 
> already done that one.....
>
> Frank Filippone
> red735i@earthlink.net
>
>
>
>
>
> _______________________________________________
> Leica Users Group.
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>
>


Replies: Reply from red735i at earthlink.net (Frank Filippone) ([Leica] Best flash for M8?)
In reply to: Message from red735i at earthlink.net (Frank Filippone) ([Leica] Best flash for M8?)