Nikkor 18 - 300mm

[Poider]

Have purchased the nikkor 18 - 300mm a few weeks ago, but have been too busy to try it, I have finally gotten the chance and have a few questions, I have the 55 - 300mm and have done some photo tests.
I put the d7000 on a tripo and took some photos of a wall from about 3 meters away at various focal lengths, with the 55 - 300mm and the 18 - 300mm at the 300mm end of the 18 - 300mm I was able to get 6 tiles vertically and 5 horizontally,
at the 300mm end of the 55 - 300mm I was able to get 3.5 tiles vertically and 2.5 horizontally.
I would estimate that from 3 meters away the 300 end of the 18 to 300 is the equivalent to 200 on the 55 - 300,
Is this normal?
Peter

[Brocken]

Hi Peter,

this article contains a response by Nikon to the problem you've described: http://www.cameralabs.com/features/18200_issue/

[Poider]

thank you I will test in sunlight tomorrow and if longer distances make a difference i will rest easy
Peter

[Brocken]

It looks as though Nikon have had to accept non-linearity of the angle of view across the zoom range as the price to be paid for acceptable sharpness at all focal lengths.

If the Nikon explanation is correct, then the discrepancy between the two lenses should disappear when they are set at infinity.

[Manfred M]

This is pretty common in the way all zoom lenses are rated; the focal length ratings are for infinity only. It's the dirty little secret that the lens manufacturers don't tell you about.

My pro f/2.8 70-200mm Nikkor at the 200mm setting is darn close to what a fixed 135mm does if I were to repeat the test you are doing.