Mike thanks for:
Raw refine: Improved the (multiple) refine feature to include the warm-cool slider setting when copying white balance parameters to multiple raw photos.
Out of interest I took some test shots which included a grey card, made copies of them and adjusted the WB using Spot Dropper on one set and the Slider on the other set.
Copying from one image to the remainder in each set worked perfectly.
However setting the WB with the slider gave a slightly different result from using the dropper, rather than the RGB values being equal, The G value was up to 5% higher when the slider was used. This may not be significant but could it create a slight green cast which would be noticeable in some situations?
Terry
That slider was meant to add or remove slight warm or cool tints from images. You can't expect a white balance slider to match a spot reading perfectly. The spot reading can match RGB channels of an arbitrary object to arbitrary lighting whereas a WB slider can only "tip the balance" between red and blue on a single generalized curve. That curve may not match how the lighting behaves in any given shot that can have complex lighting and even multi-source lighting. Not even sunlight is predictable with time of day, cloud density, reflection from surrounding objects, and many other factors at play.
Always use click-to-WB. Use of that slider should be reserved for two situations: (1) when there is absolutely nothing neutral in the frame to click WB and the photo looks too cool or too warm, or (2) you want to add a touch of warmth or a cooler look for creative effect.
Regards,
Mike