Close Up Smoke

[Stargate]

I've been trying to get the camera to move through or even close to smoke and no matter what I do I can't get a good clean edge to the smoke. It always looks blurry. I've experimented, I think, with all the settings and while I can get great looking smoke at distance I can't seem to get as sharp a close up as I would expect.

I know this is incredibly vague but I've tried to many different options to really post anything specific. I've included an example.

Any advice would be appreciated.