When I use the upload wizard, it correctly identifies the filter. But when I upload 20 images, they are all listed as V.
Images taken and calibrated with MaxIm DL Pro 5.
Have you checked what the header keyword is for the filter (and whether or not it exists?) VPHOT does allow you to define a new telescope and its particular set of header keywords.
Put Your Logo Here ...
Donate to the AAVSO via Amazon.com