What to do when you are asked to edit images that have a high ISO such as 6400, which is high; the lowest setting is usually 100. ISO in basic terms is the sensitivity of your camera to available light. Normally you would crank the ISO up in low light conditions to photograph without the use of flash. Some photographers leave the ISO on auto so it will adjust according to your aperture and shutter speed settings, which I think is what happened with these particular images. The result being noise is added to the image and reduces the detail.
We have to be realistic as to what to expect here. The photographer in this instance supplies his images in a digital format to his customers who may print up to 10”x8” in size and possibly on to canvas at a larger size, which in my experience, will be good enough to be printed on a dye sublimation printer.
To try and keep the detail I used the frequency separation technique making two layers one for the detail and the other for smoothing out the tones. In camera raw I also had to use a lot of noise reduction particularly in the couple’s plain background which I eventually masked out to replace it with a new background. Masking out the hair is always tricky to get a natural affect the noise in this instance made it difficult to separate it from the hair, so a few added steps were needed including duplicating the masked layer and setting the layer blend to multiply. The end result satisfied the photographer and his customers.