Various areas of renderings turn black upon completion

[PatrickGSR94]

I'm trying to do an interior rendering where various parts of the image turn black upon rendering completion.  It doesn't happen at all on 75 DPI, but at 150 one-fourth of the image turns black.  At 300 DPI a different odd-shaped area turns black.  The rendering looks great otherwise, all the interior lights look good, etc.  What could be causing this?  I have 2 different 3D perspective views and both are doing the same thing.

[barthbradley]

Render appearances may be missing.

https://knowledge.autodesk.com/support/revit-products/learn-explore/caas/CloudHelp/cloudhelp/2015/EN...

[PatrickGSR94]

No, all the appearance images work fine.  Lights are all fine.  The rendering looks fine until the process finishes at which point the black area appears.  Running Raytrace works fine, but I can't get a high-res image out of that, apparently.

[barthbradley]

Which Rendering Engine are you using? 

[PatrickGSR94]

Whatever Revit 2019 uses.

[PatrickGSR94]

If I shrink the view down to a really narrow field of view it works fine.  But when I pull it out to a wider field of view it makes this black rectangle nonsense.  It seems I'll have to settle for a really low-res low quality output from a saved Raytrace view to send to our client, which is really embarrassing on our part.

[barthbradley]

Have you fooled around with your Exposure settings?  

[PatrickGSR94]

Well apparently if I open Exposure Settings, adjust one slider and hit Apply, the black area disappears.  Bizarre.