On Oct 12, 2005, at 10:19 AM, Boris Liberman wrote:
http://homepage.mac.com/ramarren/photo/PAW5/40.htm
Lovely. Just lovely.
Thank you Boris!
Godfrey, I am surprised that you actually issued positive exposure
correction...
It's very important to understand the camera's metering system and
the difference between a digital camera and a film camera. Meter
calibration issues are one of the areas that you have to understand
carefully so you get what you are looking for.
The meter in the DS is calibrated to produce correct exposures for
JPEG images. Correct means not blasting out the highlights to
saturation. The result is that when you have contrasty lighting, the
meter will tend to underexpose to "protect" the highlights.
I save in RAW format most of the time. RAW format for this camera has
both greater dynamic range to work with (because the quantization
range is [EMAIL PROTECTED] vs [EMAIL PROTECTED]) AND I have explicit control
of the RAW conversion process ... I can change the gamma curve and
adjust the compression of highlights, expansion of shadow values with
fine control.
The result is that when I see a scene like this .. very contrasty
light, where the important details are, etc ... I can usually count
on the calibration of the meter being optimistic about exposure
because its calibrated to do a standard gamma curve adjustment to RGB
space. RAW has more overhead and I can crowd the highlights a little
further, get a bit more data into the dark areas, by adding a bit of
exposure and then setting an appropriate processing curve when I do
RAW conversion later.
In general, for contrasty daylight shooting, I find an EV +0.3-0.7
correction nets me very good results when storing in RAW format. If I
were storing exposures in JPEG format, I'd be a lot closer to the
camera's meter calibration most of the time.
Godfrey
