How can i tell if my nikon is a fake?

Try contact Nikonusa.com support.

There are serial numbers on all Nikon products. The serial numbers are on the outside of the nikon equipment and are very easy to find. Find them and send an email to Nikon Service. They will tell you the county of origin of the item. All newer Nikon Lenses intended for the US market have serial numbers that start with the letters "us" .

Remember, "If it sounds too good to be true, it probably is." I don't know if they ship to where you live, but amazon.com sells Nikon cameras.

Hi,
See the bottom of the cam.. There you will find one metal plate, which contains details of manufacturer, model no. serial no. and on this plate you will find the information regarding where you camera has been manufactured... Normally "Made in Japan" is treated as a best quality. "Made in Korea" Ok quality.." Made in China" is downgraded quality....
Hope this has helped you.. Please rate the answer. Thanks....

You can download a PDF copy of the manual from the manufacturer at http://support.nikontech.com/app/answers/detail/a_id/13948

If you want to purchase a paper copy, you can order one from http://www.nikonmall.com

The D90 came out in August of 2008 so how old can it be?

Hello,
The Nikon D90 works well with the Nikon AF 50mm lenses and most other brand Nikon fit AF lenses. If they are not AF you will lose autofocus and metering.
Do you know that on the D90 the lens becomes a 75mm but the aperture stays the same, so for instance the 50mm f/1.8 is a 75mm f/1.8.

I'm supposing by eyepiece you mean the rubber or plastic eyecup. The eyepiece is the whole unit that contains the lens. Nikon has a service center in many countries. If you have one in your country then they can order the part. I have ordered from Nikon. They find the part number if you tell them your model and can email you an order form. Alternately Binoculars.com is very good to deal with as is Adorama Camera in New York. Both will sell internationally.

This lens is too old for the D90, it has not got the electronics for metering and autofocus.
You can use it manually in M mode but you will have to set the aperture and shutter yourself.
The D90 manual has a section on compatible lenses, page 228 in my version.
This recommends CPU lenses for the D90, type G and D.