> Date: Wed, 09 May 2001 23:12:33 -0400
> From: "Mr. Bill" <[EMAIL PROTECTED]>
> Subject: Re: EOS Evaluative metering versus center-weighted
> 
> First there were averaging meters, they gave equal 
> emphasis to every part of the frame.  They were very 
> susceptible to giving poor exposure in backlit and 
> other non-even lighting situations.

Right, but you always knew exactly what the 
camera did and why. No hidden tricks.

> Then came center-weighted meters.  The gave much 
> more emphasis to the center of the frame and very 
> little to the edges and corners.  They were considered 
> a HUGE advance over the averaging meter for most situations.

For untrained newbies and AE modes, that is.
In manual mode the exact characteristics do
make a strong difference, and without precise
documentation may lead to misjudgings.

> Evaluative metering can vary the emphasis on different 
> parts of the frame depending on what the meter sees.  

And depending on what it is programmed to think.

> A set of parameters is stored in the cameras 
> memory to make these decisions.  

But nobody can say what the camera will do in a 
given situation. You only find out after the shot.

> For example, the top two segments see much more 
> light than the bottom two.  The camera assumes
> that this is a landscape (top two segments see sky) 
> and changes the emphasis to pay more attention to 
> the bottom two segments.  This is a simple example, 
> but a good one.  

Yes, and if the top two segments are the edge of 
a table from precious wood with the darker part 
being the shade from the table, the camera f***s
up when you try to take a picture of the wood 
structure with the table edge at the top of the 
frame.

I prefer to decide for myself if I want my table 
to turn into bright sky. Simple example, but as 
you say: A good one.

> The more segments, the more patterns that can 
> be saved.

The more segments, the more lottery.

> This is the current state of the art, with more 
> segments/patterns being assumed as better.  

Unfortunately, yes.

> One advantage to having more segments is that the
> metering can be weighted on the focusing point so 
> that you don't even need to reposition the camera 
> to meter.

And the disadvantage of this are the horrifying 
results from the D30 flash pictures, using exactly 
this scheme.

> Date: Wed, 09 May 2001 23:22:33 -0400
> From: "Mr. Bill" <[EMAIL PROTECTED]>
> Subject: Re: Canon EOS-3DV
> 
> CreoScitex has announced a 6 megapixel 
> 24mm x 36mm CMOS (C-MOST)

That is not developped or made by CreoScitex, it was
in the portfolio of CreoScitex, but engineered by a 
contractor. A sign of failure is that this contractor 
did not mention the C-most on worlds most important 
exhibition for sensors in Munich, Germany.

They had lots of press material before, but suddenly
nothing anymore.
 
> I don't believe any cameras have been sold yet, 
> based around the C-MOST chip.

And I think none will ever.

-- 
Michael Quack <[EMAIL PROTECTED]>
http://www.photoquack.de
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