KODAK WRATTEN -V- B+W: TMax 100

[Bruce Osgood]

I working with 4X5 TMax 100 now and noticed in the Kodak Publication F4016 the reference to KODAK WRATTEN Filter factoring and exposure. I have B+W filters.

How do the Wratten Factors compare to the B+W X factor? I cannot find any reference to Wratten at the Schneider site.

An example:
My B+W Red filter is B+W #90. It has an exposure factor (X) of 5 which means to open the shutter 2,5 stops. As I understand it.

The Wratten No. 25 (red) simply says open 3 stops.

For TMax 100 opening the lens for the B+W #90 3 stops is not the answer... I can prove it.

Thanks for for your thoughts,

 

[John Koehrer]

If you still have the data sheet from B+W it should have the Wratten equivalent on it. Well,at least their old ones had it.
Regarding the exposure factors, as they say YMMV.

 

[Jim Noel]

The difference in color sensitivity of the T-Max films and conventional grained films, may cause a difference in the factor for some colors of filters.

 

[DWThomas]

There's some potentially useful info here.

I agree with Jim Noel that spectral curves of specific films play a role in the results with filters.

DaveT