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Westcott Digital Calibration Target

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Anonymous
February 27, 2005 5:27:51 PM

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

Can anyone tell me how to use the Westcott Digital Calibration Target to set
white balance? I got one, but without instructions. On the Westcott
website there's a page for instructions but all the links are broken.

The target is advertised as providing exposure calibration, but I've heard
that it can also be used to set white balance for high key shotos. Can
anyone share information about that?
Anonymous
February 27, 2005 5:27:52 PM

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

Mooda wrote:
>
> Can anyone tell me how to use the Westcott Digital Calibration Target to set
> white balance? I got one, but without instructions. On the Westcott
> website there's a page for instructions but all the links are broken.
>
> The target is advertised as providing exposure calibration, but I've heard
> that it can also be used to set white balance for high key shotos. Can
> anyone share information about that?

what is white balance, and how do we get it?

it is color balancing a camera, or image
so that the white in the subject is white in the image.

we point the camera at a gray or white object,
and set color balance.

ow we just set the proper balance in the camera, like daylight,
and then use our photo software to correct the resulting image
to perfection, using a gray or white part of the picture.
white shirts or cloudy skies work perfectly.
Anonymous
February 27, 2005 8:11:27 PM

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

"Crownfield" <Crownfield@cox.net> wrote:
> ow we just set the proper balance in the camera, like daylight,
> and then use our photo software to correct the resulting image
> to perfection, using a gray or white part of the picture.
> white shirts or cloudy skies work perfectly.

Thanks, but I'm looking for information about using a Westcott Digital
Calibration Target to set correct white balance when shooting a high key
set.



The procedure you describe above is for color correction after you've shot a
scene using incorrect white balance. While that procedure can remove minor
unintended color tinges, it doesn't really restore white balance. For
example if you shoot a blue blouse on a white background using a digital
camera with an incorrect color temperature setting, the white background
won't come out looking quite white. If you then "correct" the white
background using the Curves tool in Photoshop, you unfortunately also change
the color of the blue blouse. If someone then buys a blouse based upon your
picture they will be disappointed to discover that the product color doesn't
match the pictured color.



A high key set is one in which the white background is deliberately
over-exposed to the extent that it becomes indiscernible in the photo. The
subject is lit separately, and correctly exposed. When shooting a high key
set with a digital camera, if you don't set the exposure and white balance
correctly, bands of grayish-blue or pinkish-red color appear in the digital
image. Correcting those bands without altering the exposure or white
balance of the subject can be difficult, often requiring matt work.



I've heard from several sources that the Westcott Digital Calibration Target
is very helpful in setting the correct exposure and color balance. But
there's some trick to it; it's not done in quite the same way as setting
white balance off an 18% gray card, from what I've heard.



Can someone who has used the Westcott Digital Calibration Target for high
key photography please explain the technique? Thank you in advance.
Anonymous
February 27, 2005 8:19:58 PM

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

"Mooda" <pcmooda_nospam@hotmail.com> wrote in message
news:x5-dnXdP0qjOgr_fRVn-gA@ez2.net...
> Can anyone tell me how to use the Westcott Digital Calibration Target to
> set white balance? I got one, but without instructions. On the Westcott
> website there's a page for instructions but all the links are broken.
>
> The target is advertised as providing exposure calibration, but I've heard
> that it can also be used to set white balance for high key shotos. Can
> anyone share information about that?
>
>

The links look ok here.

http://www.fjwestcott.com/instructions/target.pdf downloads just fine for
me.
Anonymous
February 27, 2005 8:36:43 PM

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

Mooda wrote:
>
> "Crownfield" <Crownfield@cox.net> wrote:

<my silly noise snipped..>

> Thanks, but I'm looking for information about using a Westcott Digital
> Calibration Target to set correct white balance when shooting a high key
> set.
>
> A high key set is one in which the white background is deliberately
> over-exposed to the extent that it becomes indiscernible in the photo. The
> subject is lit separately, and correctly exposed. When shooting a high key
> set with a digital camera, if you don't set the exposure and white balance
> correctly, bands of grayish-blue or pinkish-red color appear in the digital
> image. Correcting those bands without altering the exposure or white
> balance of the subject can be difficult, often requiring matt work.
>
> I've heard from several sources that the Westcott Digital Calibration Target
> is very helpful in setting the correct exposure and color balance. But
> there's some trick to it; it's not done in quite the same way as setting
> white balance off an 18% gray card, from what I've heard.

the white balance, custom set in the camera should still hold, right?

then the only question is how much to lighten the background.
some experimentation, looking for 255's in the white,
should get you very close. I suspect those banding problems
will happen only in overexposure overloading the sensor.

I did search in both google and google groups, and found no joy.
searching for 'high key set' got more useful information.
http://www.tallyns.com/Photo_Tech_Tips/techtips.htm


also, have you considered a chroma key blue / green background?

shoot a relatively normal shot, strip the background in processing,
and then, with the digital sensor out of the way,
juggle the forground any way you want? lighting should be easy,
and the editor should show no band problems.

any changes in the forground will have no effect on the background.

>
> Can someone who has used the Westcott Digital Calibration Target for high
> key photography please explain the technique? Thank you in advance.
!