Hi!
I have this problem, didn’t find any clues about it. The smoke renders fine, but when the camera gets real close to the smoke, it disappears. Is this a feature or a bug? I’d like to do a camera-run “through the smoke” but it doesn’t happen now as the smoke disappears when inside it… Any workarounds…?
I tried to change camera near clipping plane to .001 but it didn’t affect.
Show us what you have - screenshots and your blend file.
You say “real close” which makes me think the problem might be with the camera’s clipping limits (Camera data -> lens -> clipping -> start) It seems to be set to 0.1 for me, and I was just now able to render something inside a flame with the smoke still visible. Is the start-clipping value for you comparable to the size of the smoke?
Solvent, yes, as I mentioned, I tried to change the near clipping to .001, no effect. 
Actually I solved at least some of the case. I use cycles for everything else but smoke(as it’s not supported yet) and use the same geometry etc. for masking, and add these 2 scenes together in compositor nodes. What I’ve been doing is to just make a full copy of cycles scene, then change the rendering engine to internal, and run the smoke simulation. Then just render. That way the cyclematerials don’t render at all, but gives automatic masking for the smoke. Unless the camera is inside the smoke domain, then this bug occurs.
Would I be correct if I make the smoke sim, and then move all the geometry in the smoke scene to another layer, use that layer as a mask layer, and it will mask out the smoke?
I have had the same issue…
As the camera location gets very close to the boundary of the smoke domain the smoke fully or partially disappears. the smoke also looks different rendered from a camera positioned within the smoke domain to one outside.
Its been a real pain when I have used dynamic smoke domains and or moving cameras but to be honest I haven’t found a solution yet