Ilford SFX 200 reciprocity characteristics

[dogzbum]

After some severe Googling I am none the wiser...
Anyone want to suggest when to start making allowances for reciprocity?
Start at 1/2sec or 1sec? Double, triple times?

 

[David H. Bebbington]

Ilford of course offers film data sheets at
www.ilford.com
Strangely the sheet for SFX200 has no reciprocity-failure chart. Try the one in the data sheet for, say, HP5 Plus.

Regards,

David