Lens Diameter

[Dr. Dynamics]

How does lens diameter affect picture quality? For example compare a std 18-55 nikon lens with a 52mm diam against a 18-200mm used on the 18-55 range which has a 72mm diam?? Both having an f of 3.5:thumbup:

 

[reznap]

That's just the filter size.. or the diameter of the front element of the glass. It doesn't really have that much to do with the picture quality as far as I know. It might help (if it were larger) to render out of focus areas more smoothly and it will have some effect on the way lens flares look.

The biggest difference is that the larger it is, the more you'll pay for filters.

 

[Big Mike]

Yes, lens/filter diameter doesn't directly affect image quality.

But the design of the lens, specifically the maximum aperture, will determine what the diameter will be. And lenses with large maximum apertures, tend to be the higher quality lenses in a given line-up.

So as a generalization, lenses with bigger diameters, do tend to be higher quality.

 

[KmH]

For example compare a std 18-55 nikon lens with a 52mm diam against a 18-200mm used on the 18-55 range which has a 72mm diam?? Both having an f of 3.5

The difference is because of the maximum focal length, not image quality.

The 18-55 mm produces better overall image quality than the 18-200 because to get the 11+x focal length range of 18-200, a stacked series of design compromises have to be made.

Bigger pieces of glass cost more to make.

The longer the focal length, the larger diameter the front lens element has to be.

The larger the maximum aperture a lens is capable of, the larger diameter the front lens element has to be.