Illustration, art and graphic design.
Are these vectors or rasters? They're bloody well done if you're painting them by hand.
This is raster - in Photoshop. So easy Alex. Just create a circle with the Marquee tool, grab a big soft brush, lower the opacity and off you go. You don't run over the edges because the Marquee tool will only allow you to shade in the circle - which becomes a sphere as you shade. The lowered opacity lets you build up the shading slowly. Do you want the link to the tutorial or is this enough detail?
Thanks, but no, I get how it's done.I thought there was a chance you were doing these "freehand" (without a mask/marquee/clipping-patch/etc), and I found that possibility quite astonishing.It's still very nice shading work.