Black and white dynamic range problem - selective color change?

Chris Malcolm says...

> If your camera can produce a RAW image, then this is an
> easy job for a RAW converter, and the RAW converter that
> came with the camera will probably be the easiest to use
> for the job. You want to compress the dynamic range
> between most of the darkness of the piano and most of
> the lightness of the walls. This could be done globally
> by changing the luminance translation curve, or locally
> by using some kind of local dynamic range optimiser, if
> the RAW converter offers that.

> There are some third party dynamic range converters that
> will automatically try to do that for you on that kind
> of image, and will often do quite a good job. For
> example Picasa's RAW converter (free from Google) does
> that, and if that doesn't do enough, allows you to tweak
> it a bit more with the shadow fill slider.

Well, it's a Canon A590, and CHDK can get raw files from it,
but there's no Canon processor for them, and I don't know if
things like Picassa would recognize those files either. In
fact, it's not clear how you're supposed to process those
files. Anyway, for now I'm just using 8mp super-fine jpegs.

I've been using XnView, which has a number of global options
for changes, including contrast. And others have suggested
HDR software for this. But the problem is that the piano
itself looks good, including the black case, the white keys,
and the highlights coming off the polished brass pedals,
etc. So I really don't want to compress that. I'm pretty
new at this, but I still think I just want to knock back the
walls, and leave the rest alone.

Here's an example of what I'm dealing with, if anybody is
interested:

http://drop.io/peabody

"Peabody" <waybackNO746SPAM44@yahoo.com> wrote in message
news:0052a56f$0$16912$c3e8da3@news.astraweb.com...
> Here's an example of what I'm dealing with, if anybody is
> interested:
>
> http://drop.io/peabody

If you have a tripod, taking two or three different exposures about an
f/stop apart might give you more images to play with and combine. Yes,
10-bit raw is hardly going to be better than JPEG, if at all, so I
wouldn't waste time with that.

Installing .NET should be straight-forward, just a download - a 2.7MB
starter or a 197MB full version. Hope you have a fast connection or a
friend with one. Make sure you install the correct version for Paint.NET.
Enjoy playing with the images.

Cheers,
David

On 2009-11-06 10:13:45 -0800, Peabody <waybackNO746SPAM44@yahoo.com> said:

> Here's an example of what I'm dealing with, if anybody is
> interested:
>
> http://drop.io/peabody

I see a color cast in you example. That is probably related to white
balance. I know others have suggested shooting jpg only, however RAW
will give you the best opportunity to adjust the WB.

It will probably be worth your while to create a custom WB profile for
the lighting in that room.

Anyway, I downloaded your file and tried a couple of fixes, this being
the most satisfying to my eye.

In this case I used CS4 along with the onOne Phototools plug-in set and
applied a few of their filters to make some tweeks.

Here is an A-B comparison with your image on the left;
http://homepage.mac.com/lco/filechute/Comp-A-B.jpg


--
Regards,

Savageduck

Peabody <waybackNO746SPAM44@yahoo.com> wrote:
>Here's an example of what I'm dealing with, if anybody is
>interested:
>
>http://drop.io/peabody

I'd say forget all the fancy processing tricks, and
study up on lighting.

You've got one major source of light, and hence have a
fairly deep shadow from it (there is also very clearly a
second source, otherwise the shadow would be absolutely
black, which it isn't). But the walls are being
illuminated just as much as the piano, simply because
that source of light is far away, and thus the distance to
the walls only slightly ****her, percentage wise, than the
distance to the piano.

Use more lights. With soft light it makes little
difference how far they are from different objects, the
amount of light will be the same. With harsh point
sources of light that are very close (just out of the
camera's view) the piano can be nearly twice as close to
the light as the wall is.

And focused spotlights would also reduce illumination of
the walls, which along with the above would
significantly reduce the dynamic range of the scene.

It can also make the scene more interesting too, in
terms of tonal variations. Three or four small spot
lights on the piano, and one or two diffused sources for
fill and background, might make a much more interesting
piano.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com

On Fri, 06 Nov 2009 11:41:57 -0600, Peabody <waybackNO746SPAM44@yahoo.com>
wrote:

>David J Taylor says...
>
> >> Well, I don't mean B&W in that sense. I mean I'm
> >> trying to take a picture of a black grand piano located
> >> in a fairly small room with white walls, and when the
> >> piano looks good, the walls are blazing, and you feel
> >> an urge to reach for sunglasses.
>
> > BTW: are you shooting RAW?
>
> > David
>
>No, sorry, I should have said. It's a Canon A590. CHDK
>will make it do raw, but I've never tried that, and I don't
>know if any of the raw processors could deal with those
>files. Anyway, it's only 10-bit as I understand.

Photoline has always opened any of the CHDK cameras' RAW files just fine.
With various interpolation algorithm options as well. If you don't use that
advanced editor then use CHDK's in-camera DNG conversion to save your RAW
file data (DNG4PS intermediate computer step no longer required). Then you
can open the files direct from the camera in more rudimentary adobe
products or other editors. 10-bit or 12-bit, depending on camera model.

Floyd L. Davidson says...

> You've got one major source of light, and hence have a
> fairly deep shadow from it (there is also very clearly a
> second source, otherwise the shadow would be absolutely
> black, which it isn't). But the walls are being
> illuminated just as much as the piano, simply because
> that source of light is far away, and thus the distance
> to the walls only slightly ****her, percentage wise,
> than the distance to the piano.

> Use more lights. With soft light it makes little
> difference how far they are from different objects, the
> amount of light will be the same. With harsh point
> sources of light that are very close (just out of the
> camera's view) the piano can be nearly twice as close to
> the light as the wall is.

> And focused spotlights would also reduce illumination of
> the walls, which along with the above would
> significantly reduce the dynamic range of the scene.

> It can also make the scene more interesting too, in
> terms of tonal variations. Three or four small spot
> lights on the piano, and one or two diffused sources for
> fill and background, might make a much more interesting
> piano.

Yes, this whole project has turned out to be about lighting
much more than anything else. But the close-up shots (the
under-carriage, the bridges, the dampers, the tuning pins)
so far haven't been nearly as difficult as the shots of the
whole thing. I think that's primarily because the walls are
so close in, and so white. And of course it's easier to
maneuver the lights on the closeup stuff without having to
break out the stepladder.

I will try your suggestions. Thanks very much.

More Info says...

> Photoline has always opened any of the CHDK cameras' RAW
> files just fine. With various interpolation algorithm
> options as well. If you don't use that advanced editor
> then use CHDK's in-camera DNG conversion to save your
> RAW file data (DNG4PS intermediate computer step no
> longer required). Then you can open the files direct
> from the camera in more rudimentary adobe products or
> other editors. 10-bit or 12-bit, depending on camera
> model.

Doesn't there need to be a specific profile of some kind for
each camera model? Or are you saying a DNG file will open
up in such an application no matter what camera it came
from?

I have a vague memory of reading somwhere that camera X
wasn't supported yet by Adobe Camera Raw, so that camera's
raw files couldn't be opened. (It might have been the LX3.)
So I assumed the processing software had to specifically
support the A590's raw format or I couldn't use it.

Savageduck says...

> It will probably be worth your while to create a custom
> WB profile for the lighting in that room.

Thanks, Mr. Duck, but I don't know what a white balance
profile is, or how I would create it, or where I would use
it. And if the answer in any way involves Photoshop, then
it's just not within my frame of reference right now.

> Here is an A-B comparison with your image on the left;
> http://homepage.mac.com/lco/filechute/Comp-A-B.jpg

Thanks for doing that. But I think I need to either replace
the background completely in the picture, or do something
completely different with the lighting so I don't have to do
that.

On Fri, 06 Nov 2009 16:32:14 -0600, Peabody <waybackNO746SPAM44@yahoo.com>
wrote:

>More Info says...
>
> > Photoline has always opened any of the CHDK cameras' RAW
> > files just fine. With various interpolation algorithm
> > options as well. If you don't use that advanced editor
> > then use CHDK's in-camera DNG conversion to save your
> > RAW file data (DNG4PS intermediate computer step no
> > longer required). Then you can open the files direct
> > from the camera in more rudimentary adobe products or
> > other editors. 10-bit or 12-bit, depending on camera
> > model.
>
>Doesn't there need to be a specific profile of some kind for
>each camera model? Or are you saying a DNG file will open
>up in such an application no matter what camera it came
>from?

DNG is a standardized RAW format that most editors can open and use.
Photoline's authors use some RAW file format basics, even being able to
open RAW formats that aren't on the market yet. (Surprisingly discovered
when I tested several new RAW formats before there was even an update to
Photoline to support those makes and models of cameras.) There is the more
common Import Digital Camera RAW option in Photoline for standard digital
photography, as well as the Import RAW Image Data option. The latter being
used to open any unconventional RAW file formats that are found only in
obscure digital imaging and science circles. Allowing you to select your
color-space options, bit-patterns (8/16-bit, big/little Endian, etc.), line
overflow lengths, and header-sizes on the RAW Image Data import dialogue.

If using their Import Digital Camera RAW reading feature, just be sure to
set the gamma for Camera RAW files in the setup options to reflect the
gamma of your workspace (for PCs this is typically 2.20.) If your RAW
filename's extension (user selectable in CHDK cameras) is then associated
with Photoline, it will open them up just fine from Explorer by
double-clicking on the RAW file, using the last settings you used in the
Import Digital Camera RAW panel. The Photoline authors are also quick to
update their software to open any new RAW formats that are unique. Rather
than waiting half a year or more, you usually get the latest RAW formats
supported in the next release of Photoline, which can sometimes be several
times a month. E.g. there have been 2 official updates in the last month.
10 official updates this year so far. Many intermediate updates posted more
often depending on importance, often not logged as official version
updates. Check installer filesize, if different it's an update.

>
>I have a vague memory of reading somwhere that camera X
>wasn't supported yet by Adobe Camera Raw, so that camera's
>raw files couldn't be opened. (It might have been the LX3.)
>So I assumed the processing software had to specifically
>support the A590's raw format or I couldn't use it.
>

Adobe's software does. They'd rather invent their own proprietary
conventions and make everyone dependent on them to wait for an update,
sometimes making their users and supporters pay to do so. Others editing
software authors do not. Though adobe will support all DNG files (available
as a RAW default from all CHDK compatible cameras), DNG is one of the few
things that adobe did somewhat correctly.

See above.