[Aavso-photometry] Question RE "B" Filter Error computation

[Tim Crawford]

I did a three hour series of non filtered integrations
last night.

If weather permits tonight I was thinking of doing
some "B" filter integrations using the F chart figures
for differential reduction.

Can anyone tell me how to compute the error for the
"B" filter.

I do understand the "standard" 1/sqrt (Vcnt-Skycnt),
it would appear to me that an adjustment is also
required for the B-V error on the chart.

In addition is the B-V error data a percentage or an
absolute number?

thanks for the help and would appreicate replies
directly to me so I do not have to wait for the
digest.

Tim Crawford
Arch Cape Observatory
Oregon