When I edit my photos in my RAW editor (Canon DPP) and then transfer them into Photoshop I have found the same image to have slightly different detail in the areas where the image may sometimes show signs of slight break up/banding say in cloud/darker areas. The image is worse in the RAW editor than it is in Photoshop??

The RAW editor is using the same colour space profile I used when I calibrated my monitor.

Any ideas as to why there is a difference in the image quality and why this may be happening?.