Andy
HI
maybe I can help. I have a nikon D810 and a micrphone only works in video mode to clarify one of your questions. So if you are wanting a microphone for video work there are several things to think about.
1 =do you want a directional or stereo microphone or one that does both I have a Boya SM80 which does both depending on which direction you putthe mic heads in
2 = some microphone have fixed leads and if they get damaged bang goes the mic so get one with leads that are replaceable like mine
3= Batteries some microphones have 9v square batteries not always easy to come by if out on a shoot the boya takes 2 AAA bateries
4= some microphone are bad at picking up wind rumble so a decent muffler is worth getting
5 = don 't get a microphone that sticks out behind the camera you may not be able to use the view finder.
this is mine showing the2 mic heads that swivel- detachable lead and buttons at the back and deadcat wind muffler.
volume control and batt compartment on other side.. I now use an AZden SMX30v or a Sennheiser MKE400,
If you or anyone interested in buying it let me know