Olympus-OM
[Top] [All Lists]

Re: [OM] E system metering was Dpreview Challenges beta: First winners

Subject: Re: [OM] E system metering was Dpreview Challenges beta: First winners
From: "Ken Norton" <ken@xxxxxxxxxxx>
Date: Tue, 13 Jan 2009 11:59:04 -0600
Yes, the E-system will tend to "under-expose" very slightly--but that's
because of the design intent to protect the highlights.  However, unlike
some other brands of digital cameras, the E-system files can be pulled back
up with nasty artifacts in the shadows.  Specifically my E-1 has enough bits
assigned to the lower registers to provide boostability without solarization
and awkward noise patterns.

I'm quite leary of dialing in exposure-compensation on the E-1 to counter
this underexposure as I almost always run into two issues when I do:

1. The highlights will get weird out-of-gammut color shifts.

2. The midtones don't have the right tonal separations.

Each camera manufacturer takes the A/D data from the sensor and maps it to a
"response-curve".  This response-curve is essentially the "type of film"
being shot.  This is PRE-RAW and a vital part of the secret-sauce that
separates one brand from another.

Olympus apparently maps more bit depth into the mid-range than Canon does.
The "common wisdom" that 1/2 of the bits are associated with the top stop is
actually quite false.  That would only be true of the bits were totally
mapped in a linear fashion with no bit-bending going on.

When I meter for mid-tones, my mid-tones are more naturally saturated and
smoother than if I "expose to the right" and have to pull exposure during
RAW Conversion.

I also suspect, and this is based on studying Kodak's published response
curves of their sensors, that the sensor itself is not a linear device and
in the case of the E-1, E-300 and E-500, there is a actually a similar
hockey-stick shaped toe and shoulder.

AG
-- 
_________________________________________________________________
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