"David Bindle" wrote in message
...
I was just reading what Bob Atkins had to say about the "digital" flash
mode
on the HP945.
He demonstrates with a mountain scene. It doesn't actually fire the flash
at
all, but it lightens up darker parts of the scene. For some purposes, it
looks like a good idea to me.

I wonder, could this technique effectively replace the split neutral
density
filters that are commonly used in mountain scenics where the valleys are
so
much darker than the white capped mountains? (Of course, only in digital
cameras...)

Can you achieve this with basically all digital cameras by just reducing
the
contrast settings?

Are there any other cameras besides the HP945 that has a similar flash, or
program setting?

I wonder how well this would work for flashless portraits near full
telephoto (~300mm equiv.) to bring out shadow detail in the eyes on a
sunny
day.

Thanks for any help or info you can provide.

David



David, while it's neat that the HP-945 provides this function in-camera, the
same sort of "digital flash" can be applied out of the camera using any
fairly sophisticated photo editor such as Photoshop or Photoshop Elements.
The technique is called "constrast masking" and is used to selectively
brighten darker portions of an image while leaving the brighter parts
relatively untouched. Actually, "contrast masking" is a bit of a misnomer;
"luminance enhancement" would probably be a better term.

Here's how it's done in Photoshop Elements. With an image loaded into the
program,

1) Duplicate the image layer and make the duplicate layer the active layer
2) De-saturate the layer (ctrl-shift-U)
3) Invert the layer (ctrl-I)
4) Set the blending mode of the layer to "Overlay" or "Soft Light". Overlay
provides greater contrast.
5) Set the layer transparency to around 80%.
6) Apply a Gaussian blur to the layer. Start with something around 50 and
work up/down from there. The purpose of this blurring step is to reduce the
severity of the transitions between light and dark areas in the photo to
avoid that awful cut-and-paste look.
7) Optional--Play around with steps 4, 5 and 6 to get the most pleasing
result.
8) Flatten the image (ctrl-E)
9) Optional--Adjust Levels or Brightness/Contrast, if desired
10) Save the picture under a different name.

If you've never done this before, it might sound complicated, but it really
isn't in practice. Just a few keystrokes/button-presses and you've got an
amazingly enhanced picture in many cases and you can often even turn
throw-away shots into real keepers using this technique. ("Yes--now you can
turn TRASH into CASH!" as an infomercial might put it.) Also, if you're
using full Photoshop, not Elements, you can turn this process into an
action. Finally, to answer your other question, enhancing
brightness/contrast on a digital camera simply can't duplicate the
digital-flash/contrast-masking effect.

I'd rather do my "digital flashing" outside the camera anyway since I have
far more control over the finished result, though as I said above, it *is*
an interesting feature to include in a digital camera. BTW,
www.steves-digicams.com has an HP-945 review with a couple of digital-flash
examples along with their normally-shot counterparts so you can try out
contrast masking on your own to see how it compares to HP's implementation.

Hope this helps.