[Romanator21]

We know with the 2 second fuse that the 10m option is a no go. But the others,
we can use bombsight table 2 to back into the required IAS. 280 kph seems to be the magic number for the rest. I haven't tested yet.

The problem is that I was dropping bombs short when going 300 kph.

EDIT: I see you've reached that conclusion too.

Just as a thought, you drop on targets, that are at true 0m ?

The targets were at sea level, yes.

That bottom angle is a little distorted with 2DOF, so you have to take that into account.

Yes. However each of those plates is pretty long, so the distortion is quite small. You can "correct" for it: If you press shift+F1, the lowest plate lines up perfectly, but is now off-center. Pause the game. You can see where it indicates on the terrain (a tree for instance). Going back to normal view you can see that the same tree/object is now just on top of the windscreen frame.

So, rather than dropping where the distorted 4th angle indicates, I've been dropping when the targets disappear under my nose.

Even so, the bombs fly far short.

I can hit targets at 100 meters only by dropping in an area between the 3rd and 4th indicators.

At 50 meters, the second indicator works perfectly.