@simonbethke this is an old set of pictures and the lighting was direct instead of being indirect and the cams where too close to the subject so I did capture the back. for the whole bodies, I usually use wide angles to be able to capture all type of poses during a photoshoot, hence body are small on the images. then postshot reduces the image size giving even less details. This is my guess for the reason of the noise.
I am new to gaussian splats, so any tip is welcomed