I have a Nikon D3200 camera. I want to buy a prime lens. I read some reviews online and understand that the "Nikon AF-S NIKKOR 50mm F/1.8G" would be a good lens to buy, but this is a FX lens.

Can someone please explain me how my camera, which has DX-format sensor, can support FX lenses?


2 Answers 2


It's quite simple:

A lens projects what is called an "image circle" onto the sensor. A DX-only lens is designed to project an image circle just big enough to cover that sensor. An FX lens is designed to project an image circle big enough to cover a FX frame.

Therefore an FX lens will work on a DX sensor properly.

(But it will have an effective "crop factor" of 1.5x as you are only using the inner section of the image circle, effectively "zooming" the lens in 1.5x. That said, on a DX body the crop factor applies to all lenses, both DX and FX.)


It would seem that based on the tech specs for your camera should work fine with the lens you specified. You shouldn't have any issues with autofocus.

Under "Tech Specs:Lens"


The only other thing you should be worried about is if your lens has a built in focus motor. Some of the older lenses don't and require your camera to have one built in. If your camera doesn't then you will have to rely on manual focus.

  • \$\begingroup\$ A few DX bodies can auto-focus FX lenses that lack a focus motor - the body incorporates a focus motor and has a mechanical AF coupling in the lens mount. The early entry-level D50 can do that. Higher end DX cameras like the D7000 can too. Entry-level bodies like the D3200 can't. You can still use older AF lenses in manual-focus mode (obviously undesirable for many photographers). \$\endgroup\$ Commented Oct 20, 2013 at 22:23

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