What is the difference between Nikon primes 50mm f/1.8G and 50mm f/1.8D?
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What does G and D stands for?
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What you should be looking at is the AF or AF-S in front of the lens type.
AF-S are the ultra fast auto-focusing lenses that All Nikon dSLR cameras can use and are necessary if you are shooting with an entry level camera.
Here is a link to all the Nikkor lenses available at this time
http://www.nikonusa.com/...index.page
If you drill down on those lenses you mentioned, you will find out for yourself what those terms mean.
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G means it has no aperture ring - the aperture can only be controlled by the camera.
D means it adds distance data to the info transmitted to the camera.
This is a good site for decoding Nikkor lens nomenclature;
http://www.bythom.com/lensacronyms.htm
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