What is the transmission on this filter? For example, does it have a narrow band for phase contrast?
Leitz Wetzlar Gelbgrun
Leitz Wetzlar Gelbgrun Transmission
Leitz Wetzlar Gelbgrun Transmission
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Re: Leitz Wetzlar Gelbgrun Transmission
Good question !
Just my thoughts - not a direct answer.
One can check whether it is an interference filter or not, compare the reflected light to the transmitted light beam. They should be of very different colors.
This one does not look like an interference filter though, from the photo. So, it will not have a very narrow transmission band.
On the other hand, for phase contrast, an interference filter is not a must. The common and popular absorption green filters have a transmission peak at about 546nm, not narrow.
Yellow is 590nm and green is 550nm, thus "gelbgrun" = 570nm (?). If so, it is not the best for PC (theoretically).
On the other hand, Leitz probably made it for just that purpose (PC) so possibly by their dictionary, "gelbgrun" is about 546nm...
Just my thoughts - not a direct answer.
One can check whether it is an interference filter or not, compare the reflected light to the transmitted light beam. They should be of very different colors.
This one does not look like an interference filter though, from the photo. So, it will not have a very narrow transmission band.
On the other hand, for phase contrast, an interference filter is not a must. The common and popular absorption green filters have a transmission peak at about 546nm, not narrow.
Yellow is 590nm and green is 550nm, thus "gelbgrun" = 570nm (?). If so, it is not the best for PC (theoretically).
On the other hand, Leitz probably made it for just that purpose (PC) so possibly by their dictionary, "gelbgrun" is about 546nm...