Ekos seems to have no problem talking to the D500, and I *do* have the shutter preset to Bulb and exposure controls to M(anual). But although I have the exposure settings set to say 0.001s (for lunar) I am seeing 11s or 23s exposures when I 'Capture a preview' or run a sequence.
In the INDI Control panel for the D500, in Image Settings I have ISO 800, In Main Control I can set the Presets to 1/1000... can set the exposure to 0.001s, click Set... again, it does not seem to use the configured settings.
Hey that was it! I turned off "Force BULB" on the INDI Control Panel > Options tab and I can get fast shutter speeds for lunar and solar now!
I was only using the BULB setting because in reading the FAQs it said: Cannot connect to DSLR camera?
The following is a list of checks you need to verify before contacting support regarding DSLR connectivity issues:
...
Make sure the camera is set to Bulb/Manual mode. In some models you need to rotate the dial first to Manual then change the setttings to make it Bulb.
that made it seem like it was totally essential :/