I'm not sure whether I have created the polygons correctly but I can't seem to get a smooth surface when subdividing. Prior to this I also reduced the complexity of the mesh by reducing the number of polygons, but less polygons made it even worse when subdividing. I've also deleted doubles, converted to tris to quads but with no real success. Can anyone help? thanks
I took a default sphere with 32 segments
Into edit mode and select a single vertex. When selected then bevel it ctrlshiftb
with the faces still selected right click and select loop tools. If you do not have them then they are in the add ons (google how to use add ons from preferences). Select circle
this will give you a nice circle shape to work from.
Add knife cuts as shown or alternatively select the two verticies you want to join and press j
Select the circle edges and ctrlshiftr to offset the edge loop you have selected. This will give you 2 new edge loops.
Select the inner faces and extrude inwards three times using the normal orientation
You will end up with this topology
Add a subdivision surface modifier x 2 and set the auto smooth to 60
You can put it into a circular array and tweak the depth/scale of the hole