To convert a color image to black and white in Adobe Photoshop, you can use the Black & White adjustment layer. First, open your color image in Photoshop. Then, click on the Window menu and select Adjustments or press Ctrl+Shift+A (Windows) or Command+Shift+A (Mac). In the Adjustments panel, click on the Black & White icon. This will open the Black & White adjustment layer. In the Properties panel, you can adjust the sliders to fine-tune the conversion. You can adjust the brightness, contrast, and individual color channels to achieve the desired look.
Alternatively, you can also convert a color image to black and white by changing the color mode of your Photoshop document. To do this, go to Image > Mode > Grayscale. This will discard all the color information in the photo and convert it to grayscale. You can then adjust the brightness and contrast of the image using the Levels adjustment layer or the Curves adjustment layer. Another method is to use the Black & White adjustment layer and adjust the sliders to fine-tune the conversion. This method allows for more control over the conversion process and can produce high-quality black and white images.