Does white balance adjustment in ACR replicate what the camera settings would have been?

[Mark37430984r9lw]

The title could be cleaner, but I ran out of allowed characeters.  😊

Not sure if my camera make and model makes a difference to the answer, but I shoot in RAW with a Nikon P1000 which produces NRW files.  So, if I adjust the white balance of a photo in Adove Camera RAW, is that file in the same state as if the camera had shot the pic with the adjusted white balance?

[Stephen Marsh]

You can easily test this yourself. Replicate? Approximate?

[D Fosse]

With ACR set to white balance "As Shot", the visual appearance of white balance will be equivalent.

The numbers won't match! They will be in the same region, but you can easily get up to a few 100K discrepancy with the same visually neutral white balance.

ACR and the Nikon camera firmware are two different raw processing engines, and they won't work the same way. To produce roughly the same visual result, very different algorithms will be used, and different input values to produce the same result.

With the "As Shot" setting, ACR prioritizes visual appearance over numbers.

[Mark37430984r9lw]

I appreciate the reply, but you haven't addressed the inquiry. So, I'll be specific.  If the camera makes a RAW file at 6500 WB with a tint of 35, and I go ahead and lower WB to 5850 and keep the tint at 35, will the state of this RAW file be exactly the same as if the camera had shot it at 5850 35?

[davescm]

Simple answer - no.

As explained above - the raw file convertors are different and the images do not match when set to the same numerics.

Dave

[D Fosse]

Keep in mind that there is nothing in the camera that actually measures the color of the incoming light - that wouldn't work with all the mixed lighting you get in a practical situation.

The white balance doesn't refer to the light; it's just an amount of compensation. It tweaks a few dials in the processing pipeline until it looks visually neutral - or with a certain amount of blue or yellow color cast. Which dials to tweak in which proportion will vary with the processing engine.

Don't expect these numbers to have any particular accuracy to a standard reference.