Flash Meter w/Ortho Film?

[bvy]

I'd like to use strobes with Artista ortho lith film, which is (as the name implies) orthochromatic. The bulbs in my strobes are probably UV-coated. Even so, I'm only interested in the light that the film is sensitive to -- something in the green-blue spectrum. Does it make sense to hold a filter in front of my light meter? If so, what kind? Looking for ideas. Thanks.

 

[alanrockwood]

No filter. Just do some testing to find the appropriate exposure index for white light.

 

[Doremus Scudder]

Although ortho film is not sensitive to the entire visible spectrum, light meters are. The manufacturer of the film is fully aware of this and likely takes this into consideration when publishing the film speed. IOW, you shouldn't need to worry. However, as with all films, you should do a test for personal E.I.

Doremus

 

[bvy]

I meant to follow up on this. What I was hoping to do was calculate the effective speed of the film. Outdoors, it seems to between 3 and 6. In the studio with strobes, it's more like 0.75...

 

[Jim Noel]

I meant to follow up on this. What I was hoping to do was calculate the effective speed of the film. Outdoors, it seems to between 3 and 6. In the studio with strobes, it's more like 0.75...

That sounds about right depending on the color of the light emitted by your strobes. Many strobes are more toward the blue end of the spectrum, but some are not. It sounds as if yours contain a lot of red.