1D+RAW+CWB+ACR+Tungsten or Fluorescent=Red/Mag Cast?

Michael Lindsey said:

I'm shooting basketball under Tungsten and Fluorescent lights (2
different gyms) with a 1D, RAW, Custom White Balance set with
Expodisc, converting with Adobe Camera Raw. In both cases the
images output from ACR have a noticable red or magenta color cast.
With a little tweaking the cast can be corrected for the most part,
but still a hassle. I have processed the same images with YarcPlus
with no such color cast. Any one else experienced this? What did
you do? By the way the 1D is set for Color Matrix 4, 85mm 1.8, Av
at 2.8, ISO 1000, output in ACR as Adobe workspace. Prior to the
1D I used a D60, but never experienced this phenomena.

Click to expand...

DavidP said:

I'd suggest shooting an ExpoDisc, but overexposing by 1 - 1.5
stops, and using THAT for the custom WB.

you could also take the shot used for the custom WB (assuming you
saved it, and that it's in RAW format), and do a "click gray" to
get the WB in ACR.

To get rid of the magenta cast, you can also play around a bit with
the "tint" slider.

Michael Lindsey said:

I'm shooting basketball under Tungsten and Fluorescent lights (2
different gyms) with a 1D, RAW, Custom White Balance set with
Expodisc, converting with Adobe Camera Raw. In both cases the
images output from ACR have a noticable red or magenta color cast.
With a little tweaking the cast can be corrected for the most part,
but still a hassle. I have processed the same images with YarcPlus
with no such color cast. Any one else experienced this? What did
you do? By the way the 1D is set for Color Matrix 4, 85mm 1.8, Av
at 2.8, ISO 1000, output in ACR as Adobe workspace. Prior to the
1D I used a D60, but never experienced this phenomena.

Click to expand...

--
The Unofficial Photographer of The Wilkinsons
http://thewilkinsons.crosswinds.net
Photography -- just another word for compromise

Click to expand...

Mastrianni said:

ACR doesn't "read" or "see" matrixes, so what matrix you use has no
relevence to output. Also, I wouldn't "overexpose" for white
balance. (though I would overexpose 1/3 -1/2 stop because all the
1D's I've used seem to require that...for exposure) Use the second
square over on a MacBeth chart. (next to white) After extensive
testing, it appears ACR only reads the WB color tag, and of course
the exposure off the chip. (and applies adjusted gamma to make it
non-linear) I believe Jeff Schewe said ACR's white balance is set
for 192 192 192 RGB values.

HTH
Mastrianni

Click to expand...

Mastrianni said:

ACR doesn't "read" or "see" matrixes, so what matrix you use has no
relevence to output. Also, I wouldn't "overexpose" for white
balance. (though I would overexpose 1/3 -1/2 stop because all the
1D's I've used seem to require that...for exposure) Use the second
square over on a MacBeth chart. (next to white) After extensive
testing, it appears ACR only reads the WB color tag, and of course
the exposure off the chip. (and applies adjusted gamma to make it
non-linear) I believe Jeff Schewe said ACR's white balance is set
for 192 192 192 RGB values.

Click to expand...

DavidP said:

You need to overexpose to get a luminance value that high.

Mastrianni said:

ACR doesn't "read" or "see" matrixes, so what matrix you use has no
relevence to output. Also, I wouldn't "overexpose" for white
balance. (though I would overexpose 1/3 -1/2 stop because all the
1D's I've used seem to require that...for exposure) Use the second
square over on a MacBeth chart. (next to white) After extensive
testing, it appears ACR only reads the WB color tag, and of course
the exposure off the chip. (and applies adjusted gamma to make it
non-linear) I believe Jeff Schewe said ACR's white balance is set
for 192 192 192 RGB values.

Click to expand...

--
The Unofficial Photographer of The Wilkinsons
http://thewilkinsons.crosswinds.net
Photography -- just another word for compromise

Click to expand...

DavidP said:

If you properly expose an ExpoDisc shot, you won't get 192,192,192

You need to overexpose to get a luminance value that high.

Click to expand...

Mastrianni said:

DavidP said:

If you properly expose an ExpoDisc shot, you won't get 192,192,192

You need to overexpose to get a luminance value that high.

Click to expand...

Actually, you are correct. To be clear, it needs to be established
what that overexposure is to be consistent, ( it is not 1/2
stop,...it is much more), and do not tie your actual exposure to
it. I hope this makes sense.
As I don't use an ExpoDisc, maybe you can tell Michael what that
"overexposure value" for setting WB would be using this disc.

Regards
Mastrianni

Click to expand...

Michael Lindsey said:

Overexposing the ExpoDisc frame worked like a charm. The
192,192,192 info was also very helpful. Even when the overexposure
process is a little off, buy using the eydropper in ACR and
adjusting the exposure + - until I achieve 192,192,192, I get the
best WB that I have had in quite some time. Regardless of the cast
or ambient light temperature. At least to my eyes anyway. Thanks
again to all.

Click to expand...

DavidP said:

I hadn't thought of adjusting the exposure in the RAW conversion
process to achieve the 192,192,192 for the CWB. Neat trick.

Michael Lindsey said:

Overexposing the ExpoDisc frame worked like a charm. The
192,192,192 info was also very helpful. Even when the overexposure
process is a little off, buy using the eydropper in ACR and
adjusting the exposure + - until I achieve 192,192,192, I get the
best WB that I have had in quite some time. Regardless of the cast
or ambient light temperature. At least to my eyes anyway. Thanks
again to all.

Click to expand...

--
The Unofficial Photographer of The Wilkinsons
http://thewilkinsons.crosswinds.net
Photography -- just another word for compromise

Click to expand...