[Aavso-photometry] Cluster Photometry

[Arne Henden]

On 5/24/07, Eric Broens <Eric.Broens at skynet.be> wrote:
> Hi Arne,
>
> Isn't NGC6811 a candidate?
> I don't know if you could observe it on a sufficient number of
> photometric nights from SRO during the campaign.
> If so wouldn't these observations be suitable for determining the
> transformation coefficients?
>
There are lots of potential candidates for "standard" fields.
I've observed many fields on hundreds of nights, for example.
Such fields are good for rought calculation of transformation
coefficients, but the problem is how well do they actually
match the Landolt standard system.  There are a number of
tests that need to be made before you can trust the absolute
quality of the data.  I haven't done all of the tests to satisfy me
for more than a few such fields.
Arne