As you can see, this is a remote control using infrared. If your Coolpix S33 does not have an infrared interface, and according to the operating instructions it does not, then this remote control is of no use to you. According to Nikon, the Coolpix S33 is not compatible with this remote control because it does not have an infrared interface.
This infrared remote will not work for the D810 as far as I know.
I don't have a D810, but I believe there is a connector on it for a 10-pin plug. The suitable remote releases for this camera are MC-30, ML-3 and MC-36, although I have already seen the MC-36 remote release and had a good impression of it.
kann ich nicht beantworten weil ich Nikon D7200 habe. Schau Seite https://www.europe-nikon.com/en_GB/product/accessories/slr/slr-connectivity/remote-control/infrared-remote-control-ml-l3#related-products
I can't answer your question because I only have Camera Nikon D7200.
Look at this page, I mean it should work
http://www.nikon.ch/de_CH/search.page#keywords=ml-L3
Greetings KM
Officially, the camera is not on the compatibility list. However, it still works with the D7200. The reason is rather that the remote control was released in 2004 and the D7200 in 2015.