Reciprocity failure with digital?

I undertand that reciprocity failure does not occur with digital capture. If this is the case, can I safely assume that shutter speeds slower than 30 seconds follow the same pattern as the faster speeds? That is, they run 30secs,1min, 2mins, 4mins, etc.

Paul

Yes, you can safely assume that an exposure time of 2 minutes will provide twice the exposure of a similar 1 minute exposure, etc. The only asymmetry is that longer exposure times are generally more susceptible to fixed pattern noise (unsightly speckles which look very different from and are harder to remove than typical random noise from a high ISO).

Thanks for your help

Paul