Is 65 lumens brighter than 80?

[kelmo]

Sure if its 65 metric lumens!!!

 

[Bullzeyebill]

Now, sure, Bill, that I understand, but I think the original poster of the question
may now regret having asked it.

LOL.

Bill

 

[Coop57]

I try to enjoy my flashlights. This hurts my head.

You just need a 10 vs 9 degree beam angle

80 >enter lumens
Divide by 4Pi to get candlepower in all directions, CPALL.
6.4 =CPALL
If you have lamp cp in all directions CPALL and you know beam angle BA
then the multiplier to find beam cp BECP is
MULT
so CPALL x MULT = BECP
a = sin(BA/2), b = sqrt(4-4(a^2)),
then MULT = 4/(2-b)
then CPALL x MULT = BECP
6.4 >enter CPALL
10 >enter BA in degrees
0.087155743 =calc'd a
1.992389396 =calc'd b
525.5824763 =calc'd MULT
3346 =calc'd BECP

for 65 at 9 degrees it's
3356 =calc'd BECP