ND filter to reduce shutter time?

[Heroique]

Watch out for color shifts too.

Here’s an example:

— The first shot is w/o filtration, Astia-100F, 1/30th @ f/22.
— The second shot is also Astia-100F, w/ B+W’s 10-stop ND filter, 34 seconds @ f/22. This was taken moments later in the same light.

Based on my experience w/ Astia-100F w/o filtration, this color change is not caused by the film’s reciprocity failure. The B+W filter is responsible for it.

I’m amused that B+W would call this a “neutral” filter. Be this as it may, an 80d (blue) filter “corrects” its color influence to my satisfaction.

Tachi 4x5
Schneider XL 110mm/5.6
Astia-100F (both shots)
Epson 4990/Epson Scan

[Preston]

I have shot a lot of Astia 100F and can confirm that the color shift is not due to reciprocity failure. it is surprising that a B&W filter, that is purported to be neutral, would induce such a color shift.

--P

[Sevo]

I’m amused that B+W would call this a “neutral” filter.

B+W (and Heliopan) explicitly warn that any glass ND filter past three stop has colour shift. And while high density gelatin filters had better properties to start with, they aged rapidly - IIRC the ten stop Tiffen had a shelf life of something like two years, and was to be used within very limited humidity range.

[Heroique]

That’s interesting – I bet B+W decided that “neutral” should, nonetheless, stay in the filter’s title for marketing purposes.

I remember investigating this filter’s color shift in an earlier thread, and sharing some of the revealing data.

Down at my local Glazer’s shop, we used a sophisticated Sekonic color meter, and the B+W 10-stop filter caused a 970° K drop in temperature (more red, just as the photo shows). This was even more than I (and the Glazer’s experts) suspected – I’d even call it significantly un-neutral. A handy chart equated this change w/ a +40 nm shift.

For comparison, we also had a Nikon 2-stop and Tiffen 3-stop ND filter, and we measured these, too. The Nikon produced a 160° K rise in temperature (more blue). The Tiffen produced a 340° K rise (also more blue). These smaller changes, of course, would not be as noticeable to the naked eye (if at all). Much more “neutral,” especially the Nikon.