There is no magical size/weight advantage

Started 6 months ago | Discussions thread
Photo Pete
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Re: But there is an optical size and weight advantage!
In reply to olyflyer, 6 months ago

Photo Pete wrote:

The only thing that the designer of the CX 70-300 couldn't make significantly smaller than the FX 70-300 would be the front element diameter.

I guess you mean the rear element, not the front. The front element is dependent on the aperture, the rear on the sensor size.

Weight, main lens diameter and even length could be made less if required due to the smaller light cones required within the lens to cover the smaller sensor. Whether Nikon choose to do so is another matter.

The idea that length is not affected by being able to deal with narrower light cones is a fallacy.

The length is affected by the shorter flange back distance.

No, I mean the front element can't be made much smaller due to its physical relationship with the entrance pupil size.

Length also depends on how 'severe' the telephoto group is. A lens which is projecting a much smaller image circle can make the telephoto group far more 'aggressive' without compromising quality at the image edges.
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Photo Pete

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