Will Samyang/Pro-Optic/Bower lenses meter on my Nikon D5000?

Am planning to buy lenses (8mm fisheye, 35mm f/1.4 and 85mm f/1.4) made by Samyang. Just wanted to know if they would meter on my camera.

If they have the Nikon mount and all the properly placed connections then perhaps. Also do these lenses have built in focus and aperture motors? If not, no.

I know that the 8mm won't as there are no electronic components in it - I suspect that the other two are the same.

Provided these are the electronic current generation (*) they'll meter OK on a D5000 in all modes, including full Auto "green mode". You'll also have iris control from the body in all modes but I guess you'll prefer to work in A mode so YOU control aperture and DoF. In other words these lenses work exactly like Nikon lenses in MF modes. Now if you feel that you need to operate the iris ring manually just mount with the ring set to any value but F22 and voila you have a full manual lens.

If you run into the older pure mechanical ones you won't have light metering on the D5000, D90 and such but will work OK on the D200 upwards. You'll have to make a guess, take a 1st pic and then compensate exposure a bit. After some practice you'll dial the right compensation value right away. This is a Nikon marketing decision as the D5000 etc are deemed "amateur bodies" from Nikon's viewpoint.

* Designated AE, e.g.AE 8mm F3.5.