Minolta

> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf
> Of Aaron Bredon
>
> >> On Thu, Jun 25, 2009 at 2:47 PM, Chuck Cole <[EMAIL PROTECTED]> wrote:
> >> > High contrast copy is the opposite: it has a very abrupt change from
> >> > recording nothing (no matter the time) to the negative going all black.
> >>
> >> This is trivial to simulate with Photoshop or almost any other image
> >> editor.
> >
> > What you are describing certainly is, but what I was discussing isn't. The
> > transition is not a pure step,
> Which is why I also suggested Curves. Curves can add contrast in a
> controlled manner to a specific range of shades of the image.
>
> > and that is the essential
> > image physics needed. Photoshop cannot add image that simply was not
> > recorded.
>
> Unless the change in tones is <1/1000 of a stop, a good DSLR will record it
> when you take the picture in RAW mode and expose properly.
>
> > Without the actual sensor or film level physics, the tiny shades of gray in
> > this case are not captured at all. Maybe a grossly
> > underexposed DSLR image would suffice, but this is very hard because the
> > full moon is only a few stops down from the sun.
>
> Actually you would want an almost-OVERexposed DSLR RAW image (a DSLR will
> record 2048 distinct values in the highest stop recorded, 1024 values in the
> next highest stop, 512 values in the 3rd highest stop, and so forth).
> If you are trying to distinguish subtle shadings, you want to put them
> in the highest
> stop that the camera records.

What you seem to be missing  is that the function needed is to apply those 2048 
levels over about 1/2 stop range in the initial
exposure.  Having a dynamic range that is larger is totally unrelated to this 
case.

.. or am I missing what you are saying about using that 2048 bit range?


Chuck