re: What ever fits the tool
My baseball cap style bill is about 3†long which allows me told the bino’s with my index fingers and I turn the focusing knob which just fits at the end of the bill with my middle finger.
If the bill was any longer it would be in the way of the focusing knob. I guess with Raoul’s longer bino’s a longer bill would work OK.
I first started using this technique on the boat in foul weather trying to find a channel marker while navigating to the Petaluma River. Then it dawned on me that it would work for the cosmos.