These are looking great overall and are great fundamental practice! It's awesome seeing you limit your values so the subjects clearly stand out as light shapes against the dark background, that goes a long way towards clarity in finished pieces. Two small suggestions: 1) Some of your form edges are a bit too hard. Remember shadows happen as planes turn away from the light, so a form with sharp plane changes (like a cube) will have hard edged shadows, but a form where the planes gradually turn away from the light source (like a sphere) will have softer edged shadows. You're doing this on some of these, but there's a lot of spheres and softer forms in these with hard-edged core shadows that should be soft. 2) Watch out for your reflected lights becoming too bright. In most of these the reflected light is getting close to the value of the midtones, which starts to break apart the shadow shape and hurt the illusion of form. There are situations where this can happen, but in most cases it's best to be sure that *all* the values on the shadow side are darker than any of the values on the light side. Overall fantastic studies, keep up the good work! :D