Velvia 50 - reciprocity failure

[alvin]

Hi!
I need some help on reciprocity failure.... According to Fuji's Velvia 50 datasheet if I'm shooting for 4 seconds, apart from the CC filter I need to add 1/3 stop increase in the aperture. Must this be the case or can I extend the shutter speed? Both ways can get the same amount of light to the film right?

Ilford Delta 400 (B&W film) lists it purely as an increase in shutter speed only. Or am I comparing apples to oranges here?

BTW, reason to not want to increase 1/3 stop in the aperture side is the need for the DOF @ F22.

Thanks!

Alvin

 

[newtoforums]

Hi Alvin,

I believe you can keep your DOF n drag d shutter by 1/3 stop..

 

[sriram]

The CC filter is because Velvia turns greenish when exposed beyond 4 sec. I have had ugly green looking shots of Sentosa at night

Add 1/3 stop can be done by opening the aperture or increasing the exposure by lowering shutter speed. Both will work. I usually bracket a little (1/2 stop up and down).

 

[alvin]

Thanks mates i'll try that!

Alvin