The sizwill worked really well in this one.
Im not sure what type of tree it is, maybe some kind of aspen. It was harder timber than poplar but not as hard as ash.
It was leaning hard away from the camera and leaning back too. I had to double stack wedges to move it.
My back cut was s bit high but it was hard to line up my cuts at all as the tree was a weird shape.
I re-watched guilty of treesons famous "how to fell a try video" again recently. What i took away from it this time is that theoretically a sizwill should work better with a humboldt.
Their thinking is that when the face closes the hinge would normally break off but when you use a sizwill it allows the hinge to keep working and peel off down into the stump.
It won't work as well in a conventional face cut as the face won't fully close before the hinge breaks unless you make an awful narrow face cut.
If you watch a conventional face cut closing you'll see how the hinge tends to snap off rather than pull fibres where as when a humboldt closes it forces the tree up off the stump thus forcing fibres to pull rather than break off. Obviously variables such as hinge thickness, timber quality, etc can affect how this works out.
Sizwills have worked for me with conventional face cuts but only with naturally hingey timber like spruce or willow. Its been hit or miss with more brittle timber like ash, beech or cedar.
Food for thought. I wish id taken more photos.