Silent Image: The superior fog cloud?

[Beelzebub1111]

I suppose this all depends on how you characterize "Disbelief" is the image still there for you? because if it is, would a fog cloud created with silent image still provide concealment?

[Psyren]

Your answer lies here:

A successful saving throw against an illusion reveals it to be false, but a figment or phantasm remains as a translucent outline.

A disbelieved figment is therefore not enough to obscure vision or provide concealment.

[Chen]

But then you give your opponents the ability to save versus your fog cloud.

Of course using it to block line of sight at a distance could work (until they interact with it by shooting it or something).