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Digital Photo Exposure Compensation, White Balance In Phot..

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December 19, 2004 1:58:35 AM

Archived from groups: rec.photo.digital (More info?)

In the latest version of Photoshop (CS), it gives controls for RAW images
where you can adjust the Exposure Compensation, White Balance, etc.

Has anyone done this in previous versions of Photoshop by adjusting curves
and levels, etc? (Although not with RAW files, but JPEG, BMP, PSD, etc).
Anonymous
December 19, 2004 2:19:41 AM

Archived from groups: rec.photo.digital (More info?)

>In the latest version of Photoshop (CS), it gives controls for RAW images
>where you can adjust the Exposure Compensation, White Balance, etc.
>
>Has anyone done this in previous versions of Photoshop by adjusting curves
>and levels, etc? (Although not with RAW files, but JPEG, BMP, PSD, etc).

Before the RAW plugin for version 7, yes you had to use curves levels etc. but
RAW converters are not the same as curves and levels.
December 19, 2004 4:30:55 PM

Archived from groups: rec.photo.digital (More info?)

Do you know what parameters the RAW converters adhere to?

For example, when you change the white balance, what this actually does to
shift the colours? When adjusting exposure, what this does to shift the
exposure?



"Savidge4" <savidge4@aol.com> wrote in message
news:20041218181941.21770.00002090@mb-m14.aol.com...
>
> Before the RAW plugin for version 7, yes you had to use curves levels etc.
but
> RAW converters are not the same as curves and levels.
Related resources
Anonymous
December 19, 2004 5:53:06 PM

Archived from groups: rec.photo.digital (More info?)

Exposure Compensation lightenes or darkens the entire image giving
essentially the same results you would get by adjusting camera exposure.
White Balance adjusts the red-yellow to cyan-blue shift, effectively
changing the color temperature. It is often necessary to also use the Tint
control to get the desired color balance. If a RAW image needs only minor
corrections they can be done just as well, sometimes better in Photoshop
after conversion. Large corrections (wrong white balance, serious
over/underexposure) are best handled in the RAW conversion.
Anonymous
December 19, 2004 6:14:17 PM

Archived from groups: rec.photo.digital (More info?)

>From: "A" nospam@nospam.com

>Do you know what parameters the RAW converters adhere to?

Yes. Get the relatively cheap book by Bruce Fraser "Camera RAW with Adobe
Photoshop CS".

>For example, when you change the white balance, what this actually does to
>shift the colours?

If you understand La*b* mode then it makes more sense ... basically
'temperature' controls the yellow-blue axis and 'tint' controls the green-red
axis. Since you're working on the ungamma corrected sensor data you can do
things with white balance in the converter that have less effect on the image
quality than if you did similar corrections on the converted tiff file
(explained in the book).

>When adjusting exposure, what this does to shift the
>exposure?

The RAW exposure controls aren't as flexible as Photoshop's Curves tool but
they do allow you to change five points on the curve ... basically 'exposure'
lets you set the white point (like in Levels with the far-right slider),
'shadows' lets you set the black point and 'brightness' lets you control the
middle point (like in Levels) ... 'contrast' is basically an S-curve which
allows you to move two points between the mid-point and the end points, giving
you five points total which you can adjust for tonal corrections.

Experiment to learn more, or read the book to learn it really well.

Bill
December 19, 2004 9:42:02 PM

Archived from groups: rec.photo.digital (More info?)

Cheers Cooter and Bill for your posts. I would be interested in reading
that book as well.

The reason I ask is because with the RAW converter you are changing the
exposure, white balance, etc, for the whole photo, and it does a good job.

But, if I could get used to changing the exposure, white balance, etc
settings in Photoshop, it would mean I could have total control over the
photo, as I could just adjust exposure, etc of certain parts of the image.
For example, a black dog on snow. It would mean you could put the dog one
one layer, and the snow covered background on another layer and get the
exposures correct for both.
Anonymous
December 20, 2004 3:59:28 AM

Archived from groups: rec.photo.digital (More info?)

>From: "A" nospam@nospam.com

>The reason I ask is because with the RAW converter you are changing the
>exposure, white balance, etc, for the whole photo, and it does a good job.
>
>But, if I could get used to changing the exposure, white balance, etc
>settings in Photoshop, it would mean I could have total control over the
>photo, as I could just adjust exposure, etc of certain parts of the image.

Learn Curves, Levels, Hue/Saturation and Shadow/Highlight commands, and learn
how to mask and use the masks with adjustment layers and you'll be able to do
pretty much anything you want.

>For example, a black dog on snow. It would mean you could put the dog one
>one layer, and the snow covered background on another layer and get the
>exposures correct for both.

If you shot this in raw mode just do two conversions, one optimal for the dog
and one for the snow. Use the one with the most information (ie, the one
needing the fewest changes) as the base image, open the other one and use the
Move tool, hold down the shift key and move it to the base image, where it will
form a new layer, but covering the base image. Now with the top layer selected
do Layer > Add Layer Mask > Hide All, which masks the top layer ... now type b
to get the brush tool and paint with white at low opacity over the part of the
top image you wish to add to the base image and you'll be in business.
December 20, 2004 6:39:57 PM

Archived from groups: rec.photo.digital (More info?)

"A" <nospam@nospam.com> wrote in news:cq2ce6$31i$1@news8.svr.pol.co.uk:

> In the latest version of Photoshop (CS), it gives controls for RAW
> images where you can adjust the Exposure Compensation, White Balance,
> etc.
>
> Has anyone done this in previous versions of Photoshop by adjusting
> curves and levels, etc? (Although not with RAW files, but JPEG, BMP,
> PSD, etc).

I have Photoshop 6; the Nikon NEF plugin has controls for exposure
compensation and white balance.

Bob
!