One night I got a phone call from my friend. He purchased a Nikon D7000 with Nikon 18-200mm VR2 lens. After half year playing with the kit, he considered to add on a prime lens with big aperture to shoot indoor portraits and art exhibits in museums. He had been looking at Nikon 50mm 1.8 and Nikon 35mm 1.8 for a while and needed my advice.
I recommended the Nikon 35mm 1.8 in the beginning. The full name of the lens is AF-S DX Nikkor 35mm f/1.8G. Where AF-S indicates the lens has built-in silent motor for auto-focus, DX means the lens is designed for APS-C sensor digital SLR cameras, and G means the lens has no aperture ring. Since my friend’s Nikon D7000 is a APS-C camera, the Nikon 35mm 1.8 prime lens can be perfect match. Its big aperture and 35mm medium wide angle make it easy to capture objects in small indoor spaces. The Nikon 35mm 1.8 was first released in February 2009 and became popular in Nikon users.
My friend was happy with my introduction of the Nikon 35mm 1.8 prime lens. He also expected some knowledge about Nikon 50mm 1.8 lenses before making final decision.
There are two model of the Nikon 50mm 1.8 lenses, AF Nikkor 50mm f/1.8D and AF-S Nikkor 50mm f/1.8G.
The Nikon 50mm 1.8D was first release in 2002. It is the least expensive Nikon lens selling about $100. The Nikon 50mm 1.8D is loved by many professional photographers for its high image quality at such low cost. However the Nikon 50mm 1.8D has no auto-focus motor so that the auto-focus function will not work when use it on a camera body without built-in auto-focus motor such as Nikon D5100, D5000, D3100, D3000 and so on.
The latest released Nikon 50mm 1.8G is an upgrade of the Nikon 50mm 1.8D. It has built-in silent motor and no limits with camera bodies. Surely it cost more for the feature.
One thing need to be aware. The Nikon 50mm 1.8 lenses are designed for full frame digital SLR cameras. The actual focal length will be equivalent to 75mm when used on a APS-C digital camera like Nikon D7000. In comparison with Nikon 35mm 1.8 lens, it will be hard to capture whole image of a big or a group of objects in a small room. However the focal length of 75mm will be perfect for portraits.
Finally my friend selected Nikon 50mm 1.8G although I believe Nikon 50mm 1.8D will be good enough on his Nikon D7000. The DX format of Nikon 35mm 1.8 is a concern. You never know when you will change to a full frame digital camera.
(The sample picture was from the official site of Nikon.)