Day to night timelapse?

[Moab Man]

I recently joined the mirrorless world with a Z6ii. I am trying to learn to do a day-to-night timelapse movie of the sun setting and the Milkyway moving through. I have watched endless videos on this and have had no luck.
I tried doing aperture priority with an auto ISO with a ceiling of 800. I set the Interval to 15 seconds. My logic is that at 15 seconds it should stop the shutter from going any longer and then the ISO ceiling would allow the image to go dark because it can't go any higher. Unfortunately, in aperture priority, the camera went right past the 15-second interval.

I can't figure out how to stop the shutter from going long. I know it can be done, but none of the videos I've watched share how they are doing it.
Thanks

 

[BF Hammer]

They may be tethered to a laptop computer and controlled by software. And "tethered" can be done with WiFi on Z-series cameras. DigiCamControl even overcomes the time-lapse limitations in Nikon Z models that prevent using Manual mode.

Nikon NX Tether
DigiCamControl - I actually use this for my own astrophotography sometimes.

 

[Moab Man]

They may be tethered to a laptop computer and controlled by software. And "tethered" can be done with WiFi on Z-series cameras. DigiCamControl even overcomes the time-lapse limitations in Nikon Z models that prevent using Manual mode.

Nikon NX Tether
DigiCamControl - I actually use this for my own astrophotography sometimes.

If you don't mind me picking your brain, I am new to Z cameras and in many respects don't know enough to know what to ask. Normally, I control everything from my ASIAIR computer and shoot with a D500, 850, or Full Spectrum D600.

What are the time-lapse limitations of a Z camera?
I haven't used DigiCam in probably 10 years or so. Are you running the time lapse from the computer then? Is it doing the auto adjustments?

 

[BF Hammer]

If you don't mind me picking your brain, I am new to Z cameras and in many respects don't know enough to know what to ask. Normally, I control everything from my ASIAIR computer and shoot with a D500, 850, or Full Spectrum D600.

What are the time-lapse limitations of a Z camera?
I haven't used DigiCam in probably 10 years or so. Are you running the time lapse from the computer then? Is it doing the auto adjustments?

It is something I unexpectedly discovered, but my Z5 will not allow shooting a time-lapse in M mode. You have to use an autoexposure mode. But my D750 will happily do the same time-lapse in M mode. Or just tether the Z5 and problem solved.

DigiCamControl has improved slowly over the years. Yes I just create the entire time-lapse sequence in the software. For the time lapse it is in full control. You can even do longer than 30 second exposures as it will hold the shutter open with Bulb mode, but timed. You also can dial in ISO, shutter, aperture without touching the camera. And the trick I really like, you can focus remotely by looking at the image on the computer screen. It's sort of a manual focus-by-wire using the AF motor. Can digitally zoom in on a star and just adjust focus to make it as small a point as possible. It works on DSLR bodies also.

However the generation of DSLR matters for the interface. You will need a USB cable to connect most of them. D850 may have the most things that can be controlled, but your D600 will be sort of limited. Specifically I think ISO can not be set remotely by D600 generation bodies.

And another another possibility is using an external intervalometer that plugs in to the remote shutter-release port. You could start the time-lapse using the camera intervalometer then stop it and start the external intervalometer for the night work.