Shel and Steve ...
Important: this is for working with contrasty, sunlit scenes.
+0.3-0.7EV compensation in Auto modes or the same amount of
overexposure in Manual mode will net a better RAW format file for
processing. In normal to flat average lighting, just make the usual
exposure corrections based on the average scene reflectance you're
working with.
Remember that the thumbnail display on the LCD (and hotspot warning
in the DS) is derived from the standard in-camera JPEG rendering to
RGB. JPEG format rendering in-camera has approximately 5-6 stops of
latitude, similar to slide film (a bit more than most, really), but
with a hard saturation clip at the high end (slide film goes clear a
bit more gradually). RAW format data has more tonal scale bits to
work with and more adjustability, nets 7-9 stops of latitude with
appropriate processing. This is greater than most color negative
films and nearly as much as the widest latitude B&W available for
pictorial work.
I've been working with these basic concepts in mind for three years
with four cameras that can save to RAW format files (Oly C8080WZ, KM
A2, Canon 10D, Pentax *ist DS), and about 30,000 exposures all told.
It works and its consistent, although each of the four cameras render
thumbnails to the LCD somewhat differently.
Godfrey
On Oct 29, 2005, at 10:48 AM, Shel Belinkoff wrote:
Essentially, set the exposure comp to 1/3 to 2/3 stop ~over~ exposure.
You'll see fried highlights on the LCD screen, but that's just from
the low
quality JPEG. When looking at the files in the RAW converter,
little, and
most often nothing, is burnt out (I've not yet come across any
frame that
had fried highlights). The raw files have a lot more latitude than
the
viewed JPEGs. I'd say - perhaps somewhat exaggerated - working
with RAW
and JPEG is like using color neg vs slide film. Anyway, the idea
is to get
more detail and information in the darker parts of the image and
deal with
the highlights in the post processing.
Since trying this technique (and admittedly there has only been a days
worth of shooting to work with) my exposures have improved quite a
bit.
Can't say if this technique will work on the istD, or other digital
cameras, as they may be set up differently.
Care to share? Compensatory coffee available in London upon
application... ;-)
G gave me some exposure advice which ran counter to what
I'd been doing with the camera, and the results were great - much
better
than expected.
