saturation problem

Hello,
i´m new in fusion and today i load an exr (32bit) from maya into fusion. when i connect the color corrector node and turn the saturation to 0 the image look slightly different to the photoshop version where i open the same exr in 32 bit and turn the saturation to -100. The Original EXR Image (without modifying the saturation) looks 100% the same in fusion and photoshop. Perhaps someone in this forum can help me ? That would be great. Thanx.

Probably a difference in the algorithm equalizing the RGB values between the two softwares?

Are you using a wide gamut monitor?

Most probably different luminance math as Ivan also pointed out.

If you need to match Photoshop's exact results, you can use the BW mode of a Color Space node to choose custom weighting.