White Balance - Possible to get two different readings?

[Dinarius]

I shoot medium format to a laptop that runs on Windows XP.

I then process on a desktop that's Vista X64.

The laptop has Hasselblad Flexcolor (16bit) installed.

The desktop has Flexcolor X64bit.

For white balance, I use a basICColor grey card.

During capture, I take a white balance so that any obvious cast is removed - purely for convenience really.

Back on the desktop, I take another during processing as a matter of course.

I'm pretty sure that I'm clicking on the same place on the card and the card is spotless. But, I do get slight differences in the reading. e.g. the Temp/Tint might be 5950/7 on the laptop and then change to 5850/4 on the desktop.

Does the OS have any say in the White Balance achieved?

Thanks.

D.

[thierrylegros396]

I shoot medium format to a laptop that runs on Windows XP.

I then process on a desktop that's Vista X64.

The laptop has Hasselblad Flexcolor (16bit) installed.

The desktop has Flexcolor X64bit.

For white balance, I use a basICColor grey card.

During capture, I take a white balance so that any obvious cast is removed - purely for convenience really.

Back on the desktop, I take another during processing as a matter of course.

I'm pretty sure that I'm clicking on the same place on the card and the card is spotless. But, I do get slight differences in the reading. e.g. the Temp/Tint might be 5950/7 on the laptop and then change to 5850/4 on the desktop.

Does the OS have any say in the White Balance achieved?

Thanks.

D.

I don't think it's an OS issue.

Perhaps a diference in the ICC Profiles.

Does the 2 measurement systems use the same matrix (2x2, 3x3 or 4x4) ?

That can explain the diferences bcause the gray card is not perfectly uniform.

Have a Nice Day.

Thierry

[Panopeeper]

I'm pretty sure that I'm clicking on the same place on the card and the card is spotless

For the case you are talking about LR/ACR: when picking, have you displayed the image in the same magnification on both systems? IIRC the size of the spot ACR uses for averaging depends on the actual magnification (the program does not work with a single pixel).

[Jack Flesher]

Are you using the exact same input profile and output colorspace with each computer system?  I'd first suspect different input -- camera -- profiles are being used as mentioned above...

[Dinarius]

For the case you are talking about LR/ACR: when picking, have you displayed the image in the same magnification on both systems? IIRC the size of the spot ACR uses for averaging depends on the actual magnification (the program does not work with a single pixel).

That could be it. Flexcolor doesn't have a very high res preview.

Thanks to all.

D.