Re: Nikon D300 HDR out of the camera !!

In rec.photo.digital.slr-systems Paul Furman <paul-@[EMAIL PROTECTED]
> wrote:
> John Sheehy wrote:
>> Paul Furman <paul-@[EMAIL PROTECTED]
> wrote in
>> news:Zkszj.19705$0w.4535@[EMAIL PROTECTED]
 
>> 
>>> John Sheehy wrote:
>>>> "Charles" <charlesschuler@[EMAIL PROTECTED]
> wrote in 
>>>> news:LM6dnYaD4fw8ClHanZ2dnUVZ_oSunZ2d@[EMAIL PROTECTED]
>>>>
>>>>> Reds are often blown out.  Typical of all DSLRs. 
>>>> That's typical of conversions.  The RAW data blows out very rarely in
>>>> the red channel; it is only the attempt by the converters to render
>>>> very saturated reds that blows them out. 
>>>>
>>>> Many a digital photo with red flowers has been severely under-exposed
>>>> to prevent a blow-out, unnecessarily.
>>> Odd that red & green are opposite on the color wheel but diagonal in a
>>> sensor and double the number of green pixels. <scratching head>
>> 
>> They're not exactly opposite.  Cyan is opposite red, and magenta is 
>> opposite green.
>> 
>> Part of the range between blue and red on a color wheel would be
totally 
>> invisible, if it were fully saturated, as visible light does not use a 
>> full octave.

No reason why it should, unless like Isaac Newton you're an occultist
with strong prior reasons for believing in the magic of
octaves. That's why he invented the rather subtle extra distinction at
the blue end in order to make the number of colours in the spectrun
the magic seven, when six would have been more reasonable.

> Ah so the artist's color wheel is anthropomorphisized, not a scientific 
> relation****p?

The artist's colour wheel is intended to represent the colour mixing
and complementary relation****ps in the colours we see. Since we see
colours by using three colour filters in our eyes, it appears to us
that there are three primary colours. For example, mixing yellow and
blue to produce green isn't a fact derived from the physics of the
electromagnetic spectrum, it's an optical illusion derived from the
kind of colur filtration ond processing our brains and eyes use to
distinguish colours. So in that sense the colour wheel is
anthropomorp****sed.

> I'm a landscape architect who has spent a lot of time rendering greens 
> onto drawings and I can tell you it's just amazing how many subtle 
> greens people can distinguish. We always complained there weren't enough

> shades of green colored pencils. My most recent reminder was quickly 
> choosing a green from a Pantone color chip then getting the print back I

> was astounded how wrong the choice was. We went back to the Pantone set 
> & there simply wasn't anything close to what would have been 
> appropriate. We did find something close but it took a lot of hunting.

> How about a color system that has more bits of green distinction than 
> red or blue?

The subtlety of our green perception is probably a consequence of the
fact that one of our eye colour filters is green dominated, and the
old evolutionary bargain between plants and fruit eaters that the
plants would tell us when the fruit was ripe by switching from a
camouflaged green to a red which stood out from the green leaves.

-- 
Chris Malcolm        cam@[EMAIL PROTECTED]
              DoD #205
IPAB,  Informatics,  JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]