I saw nikon Nikon AF 70-300mm f/4.0-5.6G which works on both DX and FX sensor camera. I have Nikon D3300 which have DX sensor.

As lens works on FX sensor if we use this lense on DX camera what would be the focal length?

i'm assuming it would be 1.5*300 = 450 mm or not? (1.5 Nikon DX crop factor)

what will be the actual focal length with 2X teleconverter?( 900mm? )


1 Answer 1


Yes, you have it right. The '35mm equivalent' is the focal length x the crop factor, so a 300mm lens on a sensor with a 1.5x crop factor would be 450mm equivalent.

Adding a 2x converter to that will make it a 900mm equivalent. You will go from f5.6 to f11 with the 2x converter though.

  • \$\begingroup\$ Your answer starts out with "yes you have it right" and then goes on to explain how the OP has it wrong... interesting. \$\endgroup\$
    – user
    Mar 28, 2016 at 13:21
  • \$\begingroup\$ I did? I don't see that. I explained the 'logic' behind the numbers. OP's terminology was wrong in one or two places, but the basic premise they had was correct as far as my reading of their question goes. Their numbers are right, just in '35mm equivalent terms' not 'actual focal length' terms. Common misconception, but in very simplistic terms a 300mm lens on a 1.5x crop factor sensor would "be" a 450mm lens. \$\endgroup\$
    – floodpants
    Mar 30, 2016 at 7:29

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