Switch this in the User Preferences to one single frame:

- Bildschirmfoto 2023-10-19 um 08.51.20.png (63.34 KiB) Viewed 7087 times
Switch your project to DaVinci YRGB Color Managed.
Drop those 500 frames into the timeline, but before importing them switch this in case some of them are numbered sequentially:

- Bildschirmfoto 2023-10-19 um 08.53.54.png (113.87 KiB) Viewed 7087 times
You can do some color grading at this point, but you don't need to.
Go to Deliver and choose a stills format to your liking. Unfortunately no DNG, I'd suggest this:

- Bildschirmfoto 2023-10-19 um 08.56.24.png (44.82 KiB) Viewed 7087 times
If all of your stills are numbered sequentially, you can forget step one and just drop them onto the timeline like a video.